Haem1 Flashcards
In a patient with a deep venous thrombosis, for which of the following factors occurring in isolation at the time of the initial thrombotic event is there strongest indication for extending anticoagulation beyond six months?
A. Heterozygosity for factor V Leiden mutation.
B. Presence of a lupus inhibitor/anticoagulant.
C. Absence of a provoking stimulus.
D. Presence of an elevated homocysteine level.
E. Heterozygosity for prothrombin G20210A gene mutation.
B
QUESTION 50
Which one of the following statements is the best description of the molecular basis of a chimaeric protein (eg Bcr-Abl)?
A. Formation of disulphide bonds between cytosine residues on different peptides.
B. Post-transcription ligation of non-homologous messenger RNA (mRNA) molecules.
C. Hybrid messenger RNA (mRNA) synthesis from a bi-directional promoter.
D. Deletion of an exon from one gene.
E. In-frame ligation of the 5-end of one gene to the 3-end of another.
E
Give examples of diseases for each RBC-opathy
- Abnormality of GPI-linked proteins
- Red cell enzyme deficiency
- Haemoglobin abnormality.
- Red cell membrane abnormality.
- Haematinic deficiency. B12/Folate
- Paroxysmal Nocturnal Haemoglobulinemia.
- G6PD, Pyruvate Kinase deficiency
- Thalassemia, Sickle cell anaemia
- Spherocytosis, elliptocytosis
- B12/Folate/Iron deficiency
Why do you get leg ulcers in haemolytic disorders?
Leg ulcers may develop in patients with sickle cell anemia and other hemolytic disorders, as a result of decreased red blood cell (RBC) deformability and endothelial changes
QUESTION 51
Which of the following best explains the morphological appearance of red cells pictured below?
A. Abnormality of GPI-linked proteins.
B. Red cell enzyme deficiency.
C. Haemoglobin abnormality.
D. Red cell membrane abnormality.
E. Haematinic deficiency.
D. This is elliptocytosis
Of the following antiplatelet actions, which best describes the mechanism of clopidogrel?
A. Phosphodiesterase inhibition.
B. COX1 acetylation.
C. ADP receptor blocking. ADPase on endothelial cells. Granules released from platelets which leads to further platelet aggregation
D. GP IIb/IIIa blockade.
E. Factor Xa inhibition.
C
QUESTION 64
Which of the following is most characteristic of a patient with haemophilia A with 8% baseline factor VIII activity?
A. Spontaneous cutaneous purpura.
B. Spontaneous gastrointestinal haemorrhage.
C. Spontaneous deep muscle bleeds.
D. Spontaneous haemarthroses.
E. No spontaneous bleeding.
E. >5% activity = no bleeding
A is platelets not factors.
B doesn’t happen. (Can get haematoma)
A 69-year-old woman presents with severe pancytopenia and peripheral blood macrocytosis associated with a low serum vitamin B12 level.
Which one of the following investigation results most strongly supports a diagnosis of pernicious anaemia?
A. Positive anti-parietal cell antibody.
B. Positive intrinsic factor antibody.
C. Elevated fasting plasma homocysteine level.
D. Elevated fasting serum gastrin level.
E. Reduced red cell folate level.
B
Which of the following findings is most specific for the diagnosis of pernicious anaemia?
A. Increased serum homocysteine.
B. Increased serum methylmalonate.
C. Positive gastric parietal cell antibodies.
D. Increased serum gastrin.
E. Positive intrinsic factor antibodies.
E. Highly specific
A 21-year-old Filipino woman has been referred for investigation of anaemia. Her blood counts and iron studies are as follows:
Which of the following is the most likely diagnosis?
A. alpha+-thalassaemia trait (a-/aa).
B. alpha0-thalassaemia trait (–/aa).
C. HbH disease (–/-a).
D. beta0-thalassaemia trait.
E. beta+-thalassaemia trait.
C. HbH disease (–/-a).
A & B only give mild anaemia
In D&E, HbF makes up the majority of Hb with variable amounts of HbA2
A 65-year-old woman, established on haemodialysis for nine months, is maintained on erythropoietin 4,000 units twice a week intravenously. Previously her haemoglobin (Hb) had remained steady in the range of 105 – 115 gm/L. She now presents with a Hb of 89 gm/L on routine testing. There have been no changes to her erythropoietin dose or other medications. Her mean corpuscular volume (MCV) is 84 fL [78-98], her serum iron is 13 μmol/l [13-35], iron saturation is 18% [15-46], serum ferritin is 630 μg/l [20-300] and her reticulocyte count is 30 x 109/L [12-100].
Which of the following is the most likely cause for her erythropoietin resistance?
A. Inflammation.
B. Pure red cell aplasia.
C. Vitamin B12 deficiency.
D. Iron deficiency.
E. Hyperparathyroidism.
A
A 78-year-old woman has a history of hypertension on amlodipine, and has been found to have a persistently elevated platelet count for several months. She presents to the emergency department with abdominal pain. Her full blood examination and serum biochemistry are as follows:
Which of the following is the most likely cause of her elevated serum potassium?
A. Pseudohyperkalaemia.
B. Renal tubular acidosis.
C. Chronic renal impairment.
D. Haemolytic anaemia.
E. Lactic acidosis.
A
A previously well 37-year-old man presents with lethargy and easy bruising over several weeks. Physical examination is unremarkable apart from occasional bruises.
His full blood examination shows:
His blood film is shown below.
The most likely diagnosis is:
A. essential thrombocythaemia.
B. occult haemorrhage.
C. primary myelofibrosis.
D. occult carcinoma.
E. chronic myeloid leukaemia.
A
A 47-year-old woman has coagulation studies performed as part of preoperative assessment prior to elective hysterectomy for menorrhagia.
Which of the following is the most likely interpretation of these results?
A. Tranexamic acid therapy.
B. Disseminated intravascular coagulation.
C. Heparin exposure.
D. Von Willebrand disease.
E. Lupus anticoagulant.
E
Which of the following is the most common mechanism of a Febrile Non-Haemolytic Transfusion reaction (FNHTR) to transfusion of packed red cells?
A. Bacterial contamination of donor product.
B. Immediate hypersensitivity to proteins of donor origin.
C. Interaction between donor antibodies with recipient granulocytes.
D. Interaction between donor granulocytes with recipient antibodies.
E. Interaction between donor red cells with recipient red cell antibodies.
D
QUESTION 29
Which of the following is the greatest cause of mortality occurring more than 100 days following allogeneic peripheral blood cell stem transplantation for acute leukaemia?
A. Hepatic veno-occlusive disease.
B. Graft-versus-host disease.
C. Transplantation-related lung injury.
D. Transplantation-related infection.
E. Recurrent leukaemia.
E
A 72-year-old woman who is taking warfarin for an embolic stroke secondary to atrial fibrillation presents to the emergency department after a simple fall. On examination she has a few small bruises on her legs but is otherwise well. Her pulse is 68 bpm and irregular and her blood pressure is 175/95 mmHg. Her full blood examination is normal however her serum creatinine is elevated at 170 mcg/L [50-100 mcg/L] and her INR is elevated at 7.1.
In addition to regular monitoring, which of the following is the best management strategy for her elevated international normalised ratio (INR)?
A. Withhold warfarin.
B. Withhold warfarin and administer Vitamin K1.
C. Withhold warfarin and administer Vitamin K1 and prothrombin complex concentrate.
D. Withhold warfarin and administer Vitamin K1, prothrombin complex concentrate with fresh plasma.
E. Withhold warfarin and administer prothrombin complex concentrate with fresh plasma.
B
A 58-year-old woman has been unwell for several weeks with back pains. She has no past medical history of note. She is a smoker of 25 pack years. On examination she is tender over the mid thoracic spine and over several ribs. The rest of the examination is unremarkable. Blood tests show:
A CXR shows lytic lesions in several thoracic vertebrae with clear lung fields. Spinal X-rays confirm several lytic vertebral lesions. Immunoglobulins are normal. Serum and urine electrophoresis and immunoelectrophoresis are negative. Mammography is normal. CT scanning of chest and abdomen shows the vertebral lesions but no other masses, no organomegaly and no lymphadenopathy. Thyroid and pelvic ultrasound are normal. A bone scan shows no increased uptake.
Which of the following tests should next be performed?
A. 24 hour urine calcium.
B. Bone marrow examination.
C. Biopsy of a bone lesion.
D. Vitamin D levels.
E. Parathyroid hormone related peptide levels.
B. This woman presents with the CRAB acronym of multiple myeloma - and it’s likely nonsecretory. The other option would be serum free light chains which picks up nonsecretory disease
A 26-year-old female has been found to be homozygous for the HFE gene C282Y polymorphism, when screened for haemochromatosis. Her serum ferritin is 18 micrograms/L [15-200 micrograms/L] and her transferrin saturation is 82% [
Which of the following is the most appropriate next step in her management?
A. Venesection.
B. Observation.
C. Liver biopsy.
D. Imaging of liver for iron loading.
E. Desferrioxamine.
B
Question 51
The following mutations (Cys282Tyr and His63Asp) are associated with hereditary haemochromatosis. Which one of the following genotypes provides the greatest risk for the development of clinical disease?
A. Heterozygous Cys282Tyr.
B. Heterozygous His63Asp.
C. Double-heterozygote for Cys282Tyr and His63Asp.
D. Homozygous Cys282Tyr.
E. Homozygous His63Asp.
D
QUESTION 78
Which of the following situations is most likely to result in a false negative FDG-PET (Fluorodeoxyglucose-Positron Emission Tomography) scan when restaging a patient with aggressive lymphoma post-chemotherapy?
A. Necrosis at site of previous involvement.
B. Fibrosis at site of previous involvement.
C. Brown fat.
D. Uncontrolled diabetes.
E. Recent surgery.
D
A 67-year-old man with longstanding rheumatoid arthritis treated with methotrexate, prednisolone and celecoxib presents unwell with fatigue and anorexia. On examination his arthritis is quiescent but he has two mouth ulcers. His full blood examination is shown below.
The most appropriate drug to administer is:
A. folic acid.
B. filgrastim.
C. folinic acid.
D. cholestyramine.
E. prednisolone.
C
Which of the following transfusion reactions is leucodepletion most effective in preventing?
A. Febrile non-haemolytic transfusion reaction.
B. Transfusion associated graft versus host disease.
C. Anaphylaxis.
D. Transfusion related acute lung injury.
E. Delayed haemolytic transfusion reaction.
A
QUESTION 7
Hepcidin and ferroportin regulate systemic iron absorption by inhibition of:
A. enterocyte brush border iron reduction.
B. enterocyte apical iron uptake.
C. iron oxidation by hephaestin.
D. enterocyte basolateral iron release.
E. iron binding to transferrin.
D
QUESTION 38
Other than bacterial infections, opportunistic infection with which of the following is most likely to occur in a patient after induction chemotherapy for acute myeloid leukaemia (AML)?
A. Candida albicans.
B. Mycobacterium tuberculosis.
C. Cytomegalovirus.
D. Cryptosporidium.
E. Toxoplasma gondii.
A
A blood film showing acanthocytes and Howell-Jolly bodies is taken from a patient with
coeliac disease.
Which of the following is the most likely explanation for this appearance?
A. Malnutrition.
B. Hyposplenism.
C. Iron deficiency.
D. Hypothyroidism.
E. Folate deficiency.
B
QUESTION 46
Some autosomal recessive diseases have high prevalence in particular populations, even though they
are often fatal (e.g. Alpha thalassaemia in South East Asia; G6PD deficiency in the Mediterranean).
Which of the following is the most likely explanation?
A. Consanguinity.
B. High mutation rates in specific populations.
C. Survival advantage in heterozygous carriers.
D. Survival advantage in wild type homozygotes.
E. Founder effect.
C
A 30-year-old female presents with a painful swollen left calf. Duplex study demonstrates a proximal
deep vein thrombus extending into the ileofemoral venous system. The following laboratory results
are obtained:
Prothrombin time (PT) 16 sec [11 – 18 sec]
Activated partial thromboplastin time (APTT) 43 sec [25 – 36 sec]
Dilute Russell Viper venom test Lupus anticoagulant detected
Anticardiolipin IgG negative
Anticardiolipin IgM negative
Anti-beta 2 glycoprotein 1 moderate positive
Treatment with anticoagulation with heparin followed by warfarin therapy is commenced. Repeat
testing at 12-weeks confirms a positive anti-beta 2 glycoprotein 1. What is the most appropriate
duration of anticoagulation?
A. 3 months.
B. 6 months.
C. 12 months.
D. 24 months.
E. Lifelong.
E
QUESTION 64
A 37-year-old male is found to have some persistently enlarged lymph nodes (<2 cm diameter) in the
left posterior triangle. A biopsy reveals follicular, Grade 1, B-cell non-Hodgkin lymphoma. Staging
procedures including computed tomography (CT) scan, positron emission tomography (PET) scan and bone marrow biopsy confirm the disease is confined to a single lymph node region in the neck.
Which of the following management strategies is most appropriate?
A. Watch and wait.
B. Oral chlorambucil.
C. Radiotherapy.
D. Multiagent chemotherapy.
E. Combined modality therapy.
C
QUESTION 68
A 29-year-old woman is referred for evaluation after she was found to be heterozygous for
factor V Leiden mutation on screening. This screening was initiated when her great aunt sustained a
calf vein thrombosis following hip arthroplasty. She is currently 16-weeks pregnant and has no
personal history of venous thromboembolic disease.
Which of the following should be recommended for the remainder of her pregnancy?
A. Low molecular weight heparin.
B. Aspirin.
C. No thromboprophylaxis.
D. Surveillance ultrasonography of the lower limbs.
E. Warfarin.
C
QUESTION 74
A 67-year-old diabetic man with atrial fibrillation is taking warfarin for primary prophylaxis and is
scheduled for inguinal hernia repair. His echocardiogram shows no structural abnormality. His
international normalised ratio (INR) is 2.9. Which of the following preoperative anticoagulant
management strategies is most appropriate?
A. Withhold warfarin therapy for four days before surgery and administer low-molecular-weight
heparin (LMWH) for these four days, ceasing 24 hours prior to surgery.
B. Withhold warfarin therapy four days before surgery and administer vitamin K1 on the eveningprior to surgery if his INR> 1.5.
C. Withhold warfarin for two days prior to surgery.
D. Continue warfarin up until the time of surgery then administer prothrombin complex
concentrate on the day of surgery.
E. Withhold warfarin therapy for four days before surgery. Commence intravenous infusion of
unfractionated heparin two days prior to surgery, ceasing four hours prior to surgery.
B
QUESTION 40
Poisoning with which of the following causes a shift in the Hb-oxygen dissociation curve to the left?
A. Carbon monoxide.
B. Cyanide.
C. Gamma-hydroxy-butyrate (GHB).
D. Methanol.
E. Aspirin.
A
A 74-year-old ex-smoking male with a history of ischaemic heart disease presents with a hip fracture requiring surgical fixation within a few days. He is plethoric and there are no specific respiratory or cardiac abnormalities on examination. Chest X-ray is normal and ECG shows left bundle branch block.
His full blood count shows:
Which one of the following would be the most appropriate initial therapy?
A. Venesection.
B. Intravenous radioactive phosphorus.
C. Hydroxyurea.
D. Therapeutic anticoagulation.
E. Interferon α.
A. It is critical that the thrombocytosis and increased RBC mass is controlled pre-op otherwise the risk of arterial thrombosis is unacceptably high.
A 48-year-old previously well man, currently smoking 10 to 20 cigarettes/day, presents with the progressive onset over several months of lethargy and headache. He takes no medications.
Examination reveals him to be plethoric and hypertensive with no other significant findings.
Full blood examination shows:
Which one of the following would most strongly support a diagnosis of polycythaemia vera?
A. Raised serum vitamin B12 level.
B. Elevated total red cell mass.
C. Normal marrow karyotype.
D. Elevated serum uric acid level.
E. Lowered serum erythropoietin level.
Answer: E
A 72-year-old man with a history of chronic obstructive pulmonary disease (COPD) presents with an intercurrent lower respiratory tract infection. Apart from plethora and pulmonary signs associated with his respiratory disease, no other abnormalities are found.
Full blood examination shows:
The most likely cause of the elevated haematocrit is:
A. dehydration.
B. chronic hypoxaemia.
C. polycythaemia vera.
D. spurious polycythaemia.
E. low affinity haemoglobin.
B. The EPO level is raised.
What are the main features of polycythaemia vera?
- JAK2 mutation
- increased RBC mass
- Splenomegaly
- Normal arterial O2
- elevated WBC and platelets
What is the mechanism in polycythaemia vera?
Mechanism
Acquired JAK2 exon mutation (95% of cases) —> proliferation of all three haematopoietic cells lines (megakaryocytes, RBCs, myeloid) —> prominent overproduction of RBCs and to a lesser extent, WBCs and platelets w/ low EPO level.
What are the clinical findings in polycythaemia vera?
Clinical findings
Expanded blood volume & viscosity —> headache, dizziness, blurred vision, fatigue
Histamine release from basophilia —> fatigue
Epistaxis and GI bleeds —> abnormal platelet function and mucosal blood vessel engorgements
Plethora, engorged retinal veins
Splenomegaly
Thrombosis is major cause of morbidity and death - due to viscosity and abnormal platelets. MUST control disease before any surgery
Epidemiology of polycythaemia vera?
Epidemiology
Men in their 60s, v rare under 40
What are the lab findings in polycythaemia vera?
Elevated HCT - >54/51% M/F respectively
Elevated RBC mass
Elevated WBC and PLT counts
Normal morphology of all three lines
Basophilia and eosinophilia
Low EPO levels
JAK2 mutation positive
BMBx - hyper cellular, panhyperplasia w/ absent iron stores (transferred to circulating RBCs)
Very high B12 due to secretion of transcobalamin III from WBCs
Hyperuricaemia
Iron deficiency from bleeding & phlebotomy - microcytosis w/ normal HCT
Elliptocytosis from progressive hypersplenism
What is the diagnostic criteria for polycythaemia vera?
Major Criteria (2 Mj + 1Mn or 1st Mj + 2Mn)
Hb more than 185 in men, 165 g in women, or elevated red cell mass greater than 25%
Presence of JAK2 617V greater than F or other similar mutations
Minor Criteria
BMBx: hypercellularity w/ prominent erythroid, granulocytic, and megakaryocytic proliferation.
Serum erythropoietin level below normal range.
Endogenous erythroid colony formation in vitro.
What is the differential diagnosis of polycythaemia vera?
Spurious - elevated HCT due to volume contraction / diuretis
Secondary
- Hypoxia and smoking - carboxyhaemoglobin levels may be elevated
- renal lesions (tumor, EPO secreting tumor (rare))
- Abnormal Hb (rare)
- CML if very high WCC
- Myelofibrosis if abnormal RBC morphology and nucleated RBCs
- ET is ultra high PLT count
What is the treatment of polycythaemia vera?
Phlebotomy to maintain HCT <45%, need should gradually decrease as iron stores diminish, avoid supplementation.
Decreases thrombotic complications
Low iron diet increases intervals between phlebotomy
If unable (high req, thrombocytosis, intractable pruritus) —> hydroxurea 1st, anagrelide 2nd
Reduction of platelet count reduces complications
Avoid alkylating agents - increases risk of conversion to acute leukaemia
All patients should receive aspirin, reduces thrombosis w/o risk of excessive bleeding
Allopurinol for hyperuricaemia
Antihistamines for itch, SSRIs if intractable
What is the prognosis of polycythaemia vera?
Indolent, median survival 11-15 years
Arterial thrombosis major cause of morbidity and mortality
May convert to myelofibrosis or CML
5% to AML (rare)
What is pseudohyperkalemia?
Pseudohyperkalemia is a rise in the amount of potassium that occurs due to excessive leakage of potassium from cells, during or after blood is drawn.
Usually a lab artefact due to haemolysis during venepecture (excessive vacuum, too fine gauge), excessive tourniquet time, fist clench, delay in processing or tube dropping.
Also can occur in thrombocytosis (>500), leukocytosis (>70), or erythrocytosis (HCT >55%)
What are the features of essential thrombocythaemia?
Features
- elevated platelet count
- normal RBC mass
- absence of BCR-ABL gene
- uncommon
What is the mechanism of essential thrombocythaemia?
Mechanism
Unknown cause (high freq of JAK2 mutation) —> Proliferation of megakaryocytes —> thrombocytosis —> venous thrombosis
What is the epidemiology of essential thrombocythaemia?
Epidemiology
50-60 year olds, slightly more in women, rare
What are the clinical findings in essential thrombocythaemia?
Clinical findings
Discovery of elevated platelet count
Venous thromboses at unusual sights (i.e mesenteric, hepatic or portal vein
Erythromelalgia (painful burning of the hands)
Mucosal bleeding due to faulty platelets
Splenomegaly in at least 25%
What are the lab findings in essential thrombocythaemia?
Elevated PLT over 1-2000
Mildly elevated WBC w/ immature myeloid forms
Normal haematocrit
Smear: Large platelets, but not giant or degranulated. Normal RBC morphology
BMBx: Megakaryocytosis w/ no other morphologic abnormalities
Cytogenetics: Absent BCR-ABL (need to do to rule out CML)
JAK2 mutation in 50% of cases
What is the differential diagnosis of essential thrombocythaemia?
Reactive thrombocytosis —> PLT count not as high (less than 1000)
Inflammatory disorders (RA, UC, chronic infection)
Iron deficiency —> but thrombocytosis only if significant anaemia
Splenectomy → temporary thrombocytosis
PCV - no erythryocytosis
Myelofibrosis - normal RBC morphology, no nucleated RBCS, no giant degranulated platelets
CML - BCR ABL negative.
What is the treatment of essential thrombocythaemia?
Control platelet count w/ oral hydroxyurea, prevents thrombotic events w/o toxicity
2nd line anagrelide (low dose) - high dose = headache peripheral oedema and CHF
Vasomotor sx (erythromelalgia and parasthesias) —> aspirin
Low dose aspirin may reduce risk of thrombotic complications
Severe bleeding —> plateletpheresis
What is the prognosis in essential thrombocythaemia?
Prognosis
Indolent, high long term survival with control of thrombosis
Late: fibrotic BM, massive splenomegaly and infarction
10-15% risk of progression to myelofibrosis, 1-5% risk of transformation to acute leukaemia
A 62-year-old man with a history of controlled hypertension presents with worsening lethargy over several months and more recently, weight loss, night sweats and easy bruising. Examination reveals anaemia, bruising and firm splenomegaly 12 cm below the left costal margin; no lymphadenopathy is evident.
Full blood examination reveals:
The blood film shows:
- teardrop poikilocytosis
- large degranulated platelet
- thrombocytopaenia
- nucleated RBC
The most likely diagnosis is:
A. metastatic carcinoma.
B. megaloblastosis.
C. primary myelofibrosis.
D. systemic lupus erythematosus.
E. chronic myeloid leukaemia.
C
What are the main features of myelofibrosis?
Features
- striking splenomegaly
- teardrop poikilocytosis
- leukoerythroblastic bloods w/ giant abnormal plt
- Hypercellular BM w/ reitculin or collagen fibrosis
What is the mechanism of myelofibrosis?
Mechanism
Increased secretion of platelet-derived growth factor —> bone marrow fibrosis —> extramedullary haematopoiesis (liver, spleen, LNs), reactivation of feral mesenchymal stem cells —> splenomegaly, leukoerythroblastic blood film w/ teardrop poikilocytosis —> anaemia, splenomegaly, BM failure
What is the epidemiology of myelofibrosis?
Epidemiology
>50, insidious
What are the clinical findings in myelofibrosis?
Fatigue due to anaemia
Abdominal fullness and early satiety due to splenomegaly
Massive splenomegaly
Hepatomegaly in >50% of cases
Late: progressive thrombocytopaenia due to BM failure
Painful episodes of splenic infarction
Severe bone pain - esp upper legs
Cachexia
Portal HTN w/ ascites and varices due to hepatic haematopoeisis
Occasionally: transverse myelitis due to epidural myelopoeises
What are the lab results in myelofibrosis?
Labs
Anaemia
Variable WCC (low/N/high)
Smear: Significant poikilocytosis and teardrop RBCs, nucleated RBCs, left shifted myeloid series. Bizarre giant degranulated platelets
Triad: teardrop poikilocytos, leukoerythroblastic blood, giant abnormal platelets
BMBx: Dry tap usually but if early: hyper cellular with reticulin fibres on silver stain demonstrating fibrosis. Later: Collagen, no precursors
JAK2 mutation in 65% of cases, MPL in 40%
What is the classic finding on blood smear in myelofibrosis?
Triad: teardrop poikilocytos, leukoerythroblastic blood, giant abnormal platelets
What is the ddx of myelofibrosis?
Leukoertyhroblastosis —> severe infection, inflammation or infiltrated BM BUT no poikilocytosis/weird platelets
BM fibrosis —> metastatic ca, Hodgkin lymphoma, hairy cell leukaemia, need morphology
CML —> but normal RBCs w/ marked leucocytosis
PCV - elevated haematocrit
ET —> platelet elevation dominant
What is the treatment of myelofibrosis?
Tx
Mild —> nothing
Anaemia —> transfusion +/- EPO
Splenic enlargement / pain / severe thrombocytopaenia /high transfusion requirement —> splenectomy
Bone pain / Pulm htn —> RTx
Curative: Allo SCT
Hydroxurea or lenalidomide may help control anaemia
JAK2 inhibitors not on market yet
What is the prognosis in myelofibrosis?
Prognosis
Median survival - 5 years
End stage—> liver failure, bleeding from thrombocytopaenia, sometimes AML.
Name the microcytic anaemias
Iron deficiency
Thalassemia
Anemia of chronic disease
Lead toxicity
Name the macrocytic megaloblastic anaemias
Vitamin B12 deficiency
Folate deficiency
DNA synthesis inhibitors
Name the Macrocytic Nonmegaloblastic anaemias
Myelodysplasia
Liver disease Reticulocytosis Hypothyroidism
Bone marrow failure state
(eg, aplastic anemia, marrow infiltrative disorder, etc.)
Name the normocytic anaemias
Kidney disease
Mild form of most acquired etiologies of anemia
Under what circumstances does reticulocytosis occur?
- acute blood loss,
- recent replacement of a missing erythropoietic nutrient
- reduced red blood cell survival (ie, hemolysis)
What causes a severely microcytic anaemia?
Macrocytic?
A severely microcytic anemia (mean corpuscular volume [MCV <70 fL) is due either to iron deficiency or thalassemia, while a severely macrocytic anemia (MCV >125 fL) is almost always due to either megaloblastic anemia or to cold agglutinins in blood analyzed at room temperature.
How and where is dietary iron absorbed and stored?
Why does free iron not circulate?
- RBCs, ferritin and hemosiderin are major storage pools
- 10% of dietary iron is absorbed
- Absorbed in stomach, duodenum, jejunum under acidic conditions
- 70% of iron is in RBCs
- minor daily losses from sloughing of epithelial cells or insignificant blood losses
- free iron can produce ROS —> tissue damage, promotion of bacteria (who need it for growth
Describe the mechanism of iron transport and what affects it.
Iron transport
- across intestinal lumen by ferroportin (it is exported from the basolateral surface of the enterocyte to the circulation)
- ferroportin also facilitates transport of iron in macrophages and then to apotransferrin (transferrin) in RBCs for haemoglobin synthesis
- Hepcidin (produced during iron loading and inflammation) promotes degradation of ferroportin by binding it —> decreased release into circulation, sequestration of iron into macrophages, and decreased circulating iron
- menstrual blood loss plays a major role in iron metabolism
Anaemia of chronic disease —> body iron stores not deficient but not available for RBC production due to hepcidin stimulation
Hepcidin suppression: Fe deficiency, hypoxia, haemorrhagic or haemolytic anaemias —> release of stored iron and increased dietary absorption
In iron overload —> hepcidin deficiency
What is ferritin and what is it’s role in assessing anaemia?
Ferritin
- intracellular storage protein
- <30 indicates iron deficiency
- good marker of total body iron stores
- low ferritin seen almost only in iron deficiency
- do not reflect iron stores alone, normal-high levels does not exclude
- elevated in inflammation, infection, malignancy (blood and solid), liver, kidney disease, high BMI, post-menopause
- serum iron is poor measure, is a negative acute phase reactant in acute inflammation
- level testing not currently available
What is transferrin and what is it’s role in assessing anaemia?
Transferrin
- carrier protein for iron
- carries iron to transferrin receptor which endocytoses complex into cell which then releases iron for use or stores it
- liver synthesis apotransferrin so high levels in Fe+ defiency or high oestrogen states, low levels may be due to liver disease or inflame, it is also a negative acute phase reactant
What is the role of the soluble transferrin receptor in assessing anaemia?
Soluble transferrin receptor
- useful if presence of inflammation is obfuscating result (i.e. in inflammation)
- upregulated when iron needs are increased (i.e. deficiency, or PCV)
- not an acute phase reactant
- testing not currently rebateable
What is the transferrin saturation? When is it useful?
Transferrin saturation
- calculated ratio between serum iron and TIBC - hence influenced by anything that affects serum iron
- elevation may be earliest indicator of hereditary haemochromatosis
What are the major causes of iron deficiency?
Chronic blood loss (most important)
- Esp GI
- Aspirin/anti-inflams even w/o structural lesion
- menorrhagia or uterine bleeding
- repeated blood donations
- chronic haemoglobinuria (uncommon): traumatic haemolysis (valve), or other intravascular haemolysis i.e. PNH.
Menorrhagia and Pregnancy
- iron deficient unless supplemented, diet alone doesn’t cut it
Decreased absorption
- coeliac disease, surgical stomach resection or jejunal bypass
What are the clinical findings of iron deficiency anaemia?
Clinical findings
Anaemia —> fatigue, tachycardia, palpitations, SOBOE
Severe: skin and mucosal changes, smooth tongue, brittle nails, spooning (koilonychia) and cheilosis (inflamed corners of mouth)
Dysphagia due to oesophageal webs (Plummer-Vinson syndrome) in severe iron deficiency
Pica: often for foods not rich in iron
What are the lab findings in iron deficiency anaemia?
Lab findings
Initially iron deficiency w/o anaemia followed by anaemia and normal MCV, then hypo chromic microcytic anaemia
Ferritin <30 (or <15 is v specific but not sensitive)
Ferritin is an acute phase reactant so unreliable in response to inflammation - not ruled out if normal or elevated
Transferrin elevates to compensate leading to transferrin saturations of less than <15% (Serum iron : TIBC) however this ratio will be low in anaemia of inflammation too
Anisocytosis (size) & poikilocytosis (shape) in more severe disease, followed by severe hypochromia, target cells, or pencil/cigar-shaped cells.
What is the differential diagnosis of iron deficiency anaemia? How do you exclude them?
DDx
Anaemia of chronic disease (normal or increased iron stores in BM macrophages, normal or elevated ferritin, serum iron and transferrin saturation is low, TIBC and transferrin n/low
Thalassaemiea - greater degree of microcytosis for level of anaemia with normal or elevated RBC count (unlike every other cause of anaemia). Similar smear to severe iron deficiency
What is the treatment of iron deficiency anaemia?
Treatment
Identify cause
Ferrous sulcate, go slower and lower for compliance
Should be halfway toward normal within 3 weeks, full return to baseline after 2 months, continue for 3-6 months to replenish iron stores
Failure mostly due to non compliance, sometimes poor absorption due to stomach achlohydria - give ascorbic acid
Other: incorrect dx, ongoing GI blood loss
Parenteral iron
Indications: Intolerance to oral, refractory to oral, GI disease (usually inflammatory)
New formulation is iron oxide coated in a carbohydrate
Iron deficit = % iron deficit x normal RBC volume
I.e. if the Hb is 75% of normal then it’s 0.25 x 27ml/kg (normal RBC volume) = 337.5 grams
The dose is then iron deficit + 1 gram = 1.4gm
A 65-year-old woman, established on haemodialysis for nine months, is maintained on erythropoietin 4,000 units twice a week intravenously. Previously her haemoglobin (Hb) had remained steady in the range of 105 – 115 gm/L. She now presents with a Hb of 89 gm/L on routine testing. There have been no changes to her erythropoietin dose or other medications.
Her mean corpuscular volume (MCV) is 84 fL [78-98],
her serum iron is 13 μmol/l [13-35], iron saturation is 18% [15-46],
serum ferritin is 630 μg/l [20-300] and her reticulocyte count is 30 x 109/L [12-100].
Which of the following is the most likely cause for her erythropoietin resistance?
A. Inflammation.
B. Pure red cell aplasia.
C. Vitamin B12 deficiency.
D. Iron deficiency.
E. Hyperparathyroidism.
A. Inflammation.
B. Pure red cell aplasia. – reticulocyte count normal
C. Vitamin B12 deficiency. – not macrocytic
D. Iron deficiency. – not microcytic, ferritin up so can’t say
E. Hyperparathyroidism. – not significant
What are the essential features of the anaemia of chronic disease?
Essentials
- mild-mod normocytic or microcytic anaemia
- normal-increased ferritin
- normal-reduced transferrin
- underlying chronic disease
What are the mechanisms of the anaemia of chronic disease?
Mechanism
- EPO resistance
- inflammatory cytokines diminishing RBC production
- in the elderly: decreased EPO production due to reduced nephron mass and low level chronic inflammation. Normal serum iron
- low serum iron in inflammatory states
What are the lab findings in the anaemia of chronic disease?
Lab findings
- HCT rarely below 60% of baseline (except in renal failure)
- normal or mildly reduced MCV
- minimally changed reticulocyte count
- low serum iron
- low serum transferrin
- normal to elevated serum ferreting (if <30, coexistent iron deficiency)
- in organ failure and elderly: normal iron studies
- if ferritin super elevated —> soluble transferrin receptor (high = iron deficiency
- BMBx - absent iron staining, sequestration of iron in marrow macrophages but very rarely done.
- ultimate test: Hb response to oral iron in setting of inflammation if iron deficiency is suspected.
What are the indications for EPO therapy?
EPO indicated in:
- Hb <10 & anaemia due to RA, IBD, Hep-C, Zidovudine in HIV, myelosuppresive chemo w/ solid malignancy and palliative intent, CKD with GFR <60.
- Aim for Hb 100-120, risk of VTE and ATE
What is the significance of marked erythroid hyperplasia in the bone marrow?
A sign of ineffective erythropoiesis (expansion of the erythroid compartment of the bone marrow that does not result in the adequate production of reticulocytes in the peripheral blood).
In a transfusion-dependent patient with idiopathic acquired sideroblastic anaemia, the most appropriate treatment for prevention of transfusional iron overload is:
A. vitamin C.
B. phlebotomy.
C. desferrioxamine.
D. ethylene-diamine tetra-acetic acid (EDTA).
E. pyridoxine.
C
Aside from being an anticoagulant for blood samples, what else is EDTA used for?
Lead poisoning chelation
What are the diagnostic essentials for sideroblastic anaemia?
Diagnostic essentials
- ringed sideroblasts in the BM
- elevated serum Fe+ and transferrin saturation
What is the mechanism and causes of sideroblastic anaemia?
Mechanism
Reduced ability to synthesise or incorporate heme into protophyrin IX —> accumulation of iron in RBC precursor mitochondria
Causes
- subtype of MDS most commonly
- chronic alcholism
- lead poisoning
- drugs: isoniazid, chloramphenicol
- chronic infection/inflamattion
- inherited: x-linked
What are the clinical and lab findings of sideroblastic anaemia?
Clinical findings
- anaemia
Labs
- sideroblastic MDS: Normal or slightly elevated MCV
- all others: low
- HCT of 20-30% (moderate anaemia)
- elevated serum iron and transferrin saturation
- smear: dimorphic RBCs (normal and hypo chromic), in lead poisoning: basophilic stippling, elevated serum lead
- BMBx is diagnostic: marked erythroid hyperplasia with ringed sideroblasts (erythroid cells with iron deposits in mitochondria encircling nucleus) on Prussian blue iron stain.
What is the treatment of sideroblastic anaemia?
Treatment
- occasionally transfusions
- do NOT respond to EPO therapy
- occasionally pyridoxine
- remove offending toxin/drug in secondary forms
What is required for diagnosis of sideroblastic anaemia?
BMBx is diagnostic: marked erythroid hyperplasia with ringed sideroblasts (erythroid cells with iron deposits in mitochondria encircling nucleus) on Prussian blue iron stain.
What are the causes of B12 deficiency?
Dietary deficiency (rare)
Decreased production of intrinsic factor
- Pernicious anemia
- Gastrectomy
Helicobacter pylori infection Competition for vitamin B12 in gut
- Blind loop syndrome
- Fish tapeworm (rare)
Pancreatic insufficiency
Decreased ileal absorption of vitamin B12
- Surgical resection
- Crohn disease
Transcobalamin II deficiency (rare)
What are the essentials of diagnosis for B12 deficiency?
- Macrocytic anemia.
- Megaloblastic blood smear (macro-ovalocytes and hypersegmented neutrophils).
- Low serum vitamin B12 level.
What is the physiology of B12 absorption and utilisation?
Physiology
B12 a cofactor in conversion of homocysteine to methionine, and for conversion of methylmalonylcoenzyme A (CoA) to succinyl CoA —> annulment of Okazaki fragments during DNA synthesis of erythroid progenitor cells
Dietary B12 is animal in origin —> —> absorbed by ileum —> liver stores 2-5mg while daily utilisation is 3-5mcg —> takes 3 years for iron deficiency to occur
What are the clinical findings of B12 deficiency?
Clinical findings
Slow onset mod-severe anaemia
May be asymptomatic
Later: leukopaenia and thrombocytoapaenia
Mucosal disturbance —> glossitis
Anorexia and diarrhoea
Neurology - peripheral nerves 1st —> parasthesia —> posterior column involvement —> loss of balance or proprioception or both —> later: dementia, neuropsychiatric abnormalities, decreased vibration and position sense
Non-hematologic complications can occur w/ NORMAL FBC
What are the lab findings in B12 deficiency?
Labs
Low serum B12 (cobalamin <170, symptomatic <100
Best confirmed with an elevated level of serum methylmalonic acid (can also be elevated i kidney disease
MCV >110 (but can have normal MCV, esp with Fe deficiency or thalassaemia)
Smear: Macro-ovalocytes (megaloblastic), hyper segmented neutrophils, reduced reticulocyte count, in severe cases: reduced WCC and PLTs (B12 deficiency affects all cell lines
Elevated LDH and indirect bilirubin due to intramedullary destruction of abnormal RBCs, similar to peripheral haemolytic anaemias
BMBx - erythroid hyperplasia, megaloblastic changes in erythroid precursors: abnormally large cell size, asynchronous maturation of the nucleus and cytoplasm (normal cytoplasm maturation, impaired DNA synthesis —> abnormal nucleus)
What is the ddx of B12 deficiency anaemia?
DDx
Other megaloblastic anaemias —> but B12 will be normal
MDS - different morphology, normal B12 and methylmalonic acid levels
What is the treatment of B12 anaemia?
Treatment
IM daily for first week, weekly for first month, monthly for life
Oral when corrected, even if pernicious anaemia as will be passively diffused if unable to be actively transported - continue indefinitely
Concurrent folic acid required due to intestinal mucosal disruption for several months
Hypokalemia may occur in first few days esp if anaemia severe
Neurology reversible if <6 months duration
A 46-year-old man with hypertension and previous end stage renal failure due to glomerulonephritis,
received a kidney transplant 15 years ago. His creatinine has been stable at 110-130 μmol/L
[60 - 120 μmol/L] for the last five years. During this time his immunosuppression has been unchanged
and consists of azathioprine 100 mg daily and prednisolone 5 mg daily.
His general practitioner is concerned about his reported mean corpuscular volume (MCV) of 106 fL
[80 – 96 fL]. Which of the following is the most likely cause?
A. Folate deficiency.
B. Azathioprine.
C. Myelodysplasia.
D. Haemolysis.
E. Hypothyroidism.
B
What is the differential diagnosis in B12 deficiency?
Other megaloblastic anaemias —> but B12 will be normal
MDS - different morphology, normal B12 and methylmalonic acid levels
What is the treatment of B12 deficiency anaemia?
Treatment
IM daily for first week, weekly for first month, monthly for life
Oral when corrected, even if pernicious anaemia as will be passively diffused if unable to be actively transported - continue indefinitely
Concurrent folic acid required due to intestinal mucosal disruption for several months
Hypokalemia may occur in first few days esp if anaemia severe
Neurology reversible if <6 months duration
A 42-year-old woman presents with several weeks of lethargy and is found to be clinically anaemic and mildly icteric. There is no history or clinical evidence of overt blood loss. She has a normal varied diet and is on no medication.
Her full blood count shows:
The blood film shows macrocytosis and a hypersegmented neutrophil
The most likely diagnosis is:
A. pernicious anaemia.
B. Evans’ syndrome (autoimmune haemolytic anaemia and thrombocytopenia).
C. aplastic anaemia.
D. hypothyroidism.
E. alcoholic liver disease.
A. Results in B12 deficiency –> megaloblastic anaemia
What are the causes of folate deficiency?
Dietary deficiency
Decreased absorption
- Tropical sprue
- Drugs: phenytoin, sulfasalazine, trimethoprim-sulfamethoxazole Concurrent vitamin B12 deficiency
Increased requirement
- Chronic hemolytic anemia
- Pregnancy
- Exfoliative skin disease
Excess loss:
- hemodialysis
Inhibition of reduction to active form
- Methotrexate
What are the essentials for diagnosis of folate deficiency?
- macrocytic anaemia
- megaloblastic smear (macro-ovalocytes and hypersegmented neutrophils
- normal serum B12 levels
- reduced serum folic acid levels
What is the physiology of folate?
Physiology
- real name: pteroylmonoglutamic acid
- citrus and leafy greens
- stored for 2-3 months
- absorbed throughout entire GI tract
- absorption impaired by drugs or full length mucosal disruption
- increased requirements in pregnancy, haemolytic anaemia and exfoliative skin disease
What are the signs and symptoms of folate deficiency?
Signs and symptoms
- anaemia
- mucosal megaloblastic changes
- NO neurological abnormalities
What are the lab findings in folate deficiency?
Macrocytic anemia.
Megaloblastic blood smear (macro-ovalocytes and hypersegmented neutrophils).
Normal serum vitamin B12
Low red blood cell folate (preferred as reflects stores over lifespan of RBC)
What is the ddx of folate deficiency?
- B12 deficiency - check level
- alcoholic nutritional deficiency —> no megaloblastic changes but TARGET cells
- hypothyroidism assoc w/ pernicious anaemia
What is the treatment of folic acid deficiency?
Tx
Daily PO folic acid, similar response as in B12 replacement
- MUST check B12, large doses of folic acid will correct bloods but will allow ongoing neurologic damage.
Graft-versus-host disease is a major complication of allogeneic stem cell transplantation for haematological malignancy in adults.
Which one of the following has the least influence on the risk of developing graft-versus-host disease?
A. Age of recipient.
B. Donor-recipient ABO blood group incompatibility.
C. In vitro T cell depletion of the graft.
D. Type of HLA-matched donor (sibling versus unrelated).
E. Donor-recipient HLA mismatch.
B. Donor-recipient ABO blood group incompatibility.
The major cause of death in patients more than six months following cardiac transplantation is:
A. graft-versus-host reaction.
B. opportunistic infection.
C. rejection.
D. malignancy.
E. coronary artery disease.
E
A 42-year-old man with acute myeloid leukaemia undergoes allogeneic stem cell transplantation from a human leucocyte antigen (HLA)-matched sibling. He is progressing well for the first 10 days, but then complains of abdominal pain and leg swelling.
He is noted to have marked ascites, moderate peripheral oedema and jaundice.
Liver function tests are as follows:
An abdominal ultrasound confirms large volume ascites with an enlarged liver (span 18 cm). The spleen is normal in size.
The most likely explanation for his condition is:
A. graft-versus-host disease.
B. cytomegalovirus hepatitis.
C. hepatosplenic candidiasis.
D. portal vein thrombosis.
E. veno-occlusive disease.
E. veno-occlusive disease.
Which of the following is the greatest cause of mortality occurring more than 100 days following allogeneic peripheral blood cell stem transplantation for acute leukaemia?
A. Hepatic veno-occlusive disease.
B. Graft-versus-host disease.
C. Transplantation-related lung injury.
D. Transplantation-related infection.
E. Recurrent leukaemia.
E
What are the early post hematopoetic stem cell transplant complications?
Mucositis (most common)
Haemorrhagic cystitis
Prolonged and severe pancytopaenia
Infections
CMV
EBV
Viral hepatitis
Acute GVHD
Graft failure
Transplant related lung injury
Hepatic veno-occlusive disease
Transplant related MAHA
What is the most common early HSCT transplant complication?
What causes it?
How do you treat it?
Mucositis
- most common short-term complication
- etoposide and MTx
- can be oropharyngeal and intestinal
- intubation if supraglottic
- may need TPN
- topical and systemic analgesia and opioids
When does severe pancytopaenia occur in HSCT? How is it managed? When do infections occur?
Prolonged & severe pancytopaenia
- common, lasts up to 4 weeks
- empiric anti fungal tx if persistent unexplained fever in setting of use of broad-spectrum abc
- antiviral prophylaxis usually given
- serious infections (pneumonia, bacteraemia, fungaemia, viraemia) in up to 50% - more common in matched unrelated donors (MUDS) than auto or sibling allografts.
- recombinant growth factors (filgrastim) started 24-72 hours post stem cell infusion reduce neutrophil recovery time
- severe thrombocytopaenia —> transfuse <10, or 50 if surgery required.
- severe anaemia —> transfuse, sometimes EPO
What is the timeline of infection in HSCT?
Infections
Early (0-30 days) - mucosal and skin injury —> aerobic bacteria (esp coag -ve staph, viridans step, gram -ve’s candida and HSV).
Mid 1-3 months: T-cell dysfunction, hypogammaglobulinaemia —> encapsulated bacteria (pneumococcus, H.influenzae), viruses (CMV, PHP), molds and candida
Later 3-12 months - t-cell reconstitution, chronic GVHD —> encapsulated bacteria, CMV, PJP, HZV, EBV and hepatitis
What causes CMV and EBV infection in HSCT?
CMV
- due to impaired viral immunity in first year, acute or chronic GVHD
- CMV positivity = higher peritransplanatation mortality rate. - treated prophylactically and preemptively to prevent pneumonitis and viraemia but can still occur
EBV
- most common in patients who are EBV naive, in patients receiving T-cell depleted grafts, or receiving ATG for in-vivo t-cell depletion.
- causes posttrantplant lymphoproliferative disorder (PTLD) in HSCT, t-cell depleted grafts, and those undergoing intensive tx for GVHD
What role does viral hepatitis play in HSCT?
Viral hepatitis
- third most common cause of liver disease in transplant patients
- can reactivate HBV at 3-6 months due to impaired cellular immunity
- HBsAg +ve = prophylactic antiviral tx pre-chemotherapy and for 3/12 after.
- if -ve, need vaccination before transplant
- HCV has little impact but is a risk factor for hepatic veno-occlusive disease and GVHD
- faster progress of HCV to fibrosis and cirrhosis, decompensation and malignancy in HSCT. Third leading cause of late deaths after transplant - need definitive management after 6 months and no evidence of GVHD.
What causes GVHD in HSCT? Who gets it? How do you reduce it?
Donor immunocompetent T-cells and NK cells recognise host antigen as foreign —> immune reaction
- mainly in allograft setting (not auto or syngeneic (twin)
- severity of GVHD inversely related to risk of relapse due to relationship with graft-versus-leukaemia effect.
- reduction achieved by optimising donor and graft type and post-transplant immunosuppresion.
- least with peripheral blood HSCT, worst with umbilical cord HSCT
When does acute GVHD occur, what does it affect, what are the risk factors, pathogenesis and treatment?
- common, within first 100 days
- skin, mucosa, gut, and liver
- erythematous macular skin rash —> blistering (like burns), severe abdominal pain, profound diarrhoea, hyperbilirubinaemia.
- Stage 1 skin up to stage IV (systemic). III-IV have a bad prognosis.
- RFs: HLA mismatch, MUD grafts, grafts from a parous female donor, older age
- pathogenesis: acute cytokine storm (TNF and IL-1) released due to damaged host tissue from induction —> increased MHC expression —> recognition of minor HLA differences by T-cells —> proliferation and cytokine release —> further recruitment of t-cells and macrophages —> release of TNF and IL-1 —> vicious cycle of inflammation and tissue damage
- prophylaxis better than treatment: graft t-cell depletion (but increased risk of graft failure and rate of relapse due to graft vs tumour effect
- prevention: CNi (renal toxicity) + MTx (but mucositis), sirolimus and MMF have less toxicity. Can also use gut decontamination with metro, IVIG or less intensive regiment
- high dose steroids and ATG does not work.
Who gets chronic GVHD?
What are the risk factors?
What are the clinical features
How do you manage it?
- 40-80% of long term survivors, incidence rising as older patients get transplants
- RFs: peripheral blood transplants, mismatch or unrelated donors, second transplant, donor leukocyte infusions
- greatest risk for chronic GVHD is acute GVHD
- 2-12 months post transplant - skin, eyes, mouth, liver, fascia, any organ
- chronic lichenoid skin changes, dry eyes and mouth, impaired ROM from fibrosis of dermis and fascia. Resembles scleroderma or other autoimmune diseases
- immunosuppression with steroids, tacrolimus and MMF are mainstays, hydroxychloroquine works well too.
- major cause of death: profound immunodeficiency, need prophylaxis against encapsulated organisms
- patients with frequent infections and low Ig levels should get IVIG
What are the risk factors for, and treatment of HSCT graft failure?
Graft failure
- associated with HLA mismatch, more frequent in MUD grads
- other RFs: aplastic anaemia, t-cell depletion, infusion of lower number of stem cells (cord blood), nonmyeloablative transplants, GVHD, splenomegaly
- poor graft function can be treated with growth factors (G-CSF or GM-CSF), and EPO.
- Failure: second stem cell infusion
What are the early pulmonary complications of HSCT transplant? Treatment?
Transplantation-relation lung injury (TRLI)
- acute inflame response —> severe lung injury
- allogenic transplant
- early tx w/ corticosteroids and etanercept (anti-TNF) reduces extent
Interstitial pneumonitis (usually CMV) is frequently fatal - reduced w/ anti-infective prophylaxis and CMV-ve blood products (leukodepletion, CMV -ve donors), tx w/ ganciclovir or foscarnet + IvIg
Autograft - diffuse alveolar haemorrhage
RTx or pulm toxins, MTx or carmustine
What is Sinusoidal Obstruction Syndrome? What are the risk factors? Pathogenesis? Treatment? Outcomes?
Hepatic veno-occlusive disease (Sinusoidal Obstruction Syndrome)
- very common, potentially lethal
- 10-60% of patients, 50% of post-transplant deaths
- weight gain, tender hepatomegaly, jaundice and ascites —> fulminant multiorgani failure
- 8-10 days post inductions
- RFs: prior liver damage, high levels of busulphan, >10-12 Gy total body irradiation, heavy induction, C282Y positivity of haemochromatosis gene
- pathology: elevated TNF —> sinusoidal endothelial damage —> sloughs —> obstructs hepatic circulation —> centrilobular hepatic injury and portal hypertension.
- Prevention is best treatment: avoid fludarabine or cyclophosphamide, use nonmyeloablative regiment
- Ursofalk reduces risk of this and grades III-IV GVHD
- Treatment is supportive, with defibrotide which is antithrombotic and fibrinolytic (avoid heparin and TpA)
What are the late complications of HSCT transplant?
- organ toxicity from chemo
- posttransplanation immunosuppression
- Chronic GVHD
- endocrine disease and heart failure
- increased risk of malignancy years later: acute leukaemia’s, solid tumours, MDS, disease and regimen dependent, increased prevalence after total-body irradiation
- late infections (months), usually in assoc w/ GVHD or GVHD therapy
- Vaccines: pneumococcus, H.influenzae, Hep-B, polio, ADT, influenza - recommence at 18 months
Ocular
- cataract formation
- dry eyes due to chronic GVHD
Bronchiolitis obliterans
- HSCT recipients, fatality rate 50%
- no response to steroids
MSK
- OP, and avascular necrosis
- bisphosphonates
Neuropsych disorders
- usually due to cranial irradiation
What are the long-term immune effects of HSCT transplant?
- host immunity suppressed months-years
- worse after allograft
- related to severity of induction, acute GVHD, ongoing immunosuppression for GVHD
- complete reconstitution may take years due to less active (or even absent) thymic function the older you get.
Which HLA loci must be matched in allo-HSCT?
Donor must be matched with the patient (recipient) at the HLA loci (HLA A, B, C, DR) that specify major histocompatibility antigens.
Where are donor stem cells collected from in allo-HSCT?
- umbilical cord blood units may also be used.
- bone marrow
- more commonly through leukopheresis of the blood after mobilizing hematopoietic stem cells from the bone marrow with filgrastim (G-CSF).
What is the initial period of pancytopaenia following induction and HSCT-transplant?
There is a period of pancytopenia in the gap between the effect of the chemotherapy given to the patient and the time it takes the infused hematopoietic stem cells to grow into bone marrow, usually 10–14 days.
What is the major cause of morbidity and mortality in allo-HSCT?
How is it managed?
GVH is the major cause of morbidity and mortality during an allogeneic SCT. Immunosuppression must be given during allogeneic stem cell transplantation to reduce the incidence and severity of GVH reaction.
CnI plus MTx
Assuming no complications, when does immunosuppression post HSCT transplant cease?
In most cases of allogeneic stem cell transplantation, the immunosuppression can be tapered and discontinued 6 or more months after transplantation.
What is the graft-versus malignancy (GVM) effect?
How does this relate to graft-versus-host disease?
What is the treatment implication?
Residual cancer cells can be recognized as foreign by the donor immune system and killed.
Intensity of GVHD correlates with GVM (rate of graft failure is inversely proportional to severity of GVHD)
Reducing the intensity of the induction regimen, relying for cure more on the GVM effect than the myeloablation. Allo-SCT is now being offered up to age 60 in some cases.
When is allo-HSCT curative?
Acute leukaemias (AML, ALL)
MDS
CML (refractory to TKIs)
Severe aplastic anaemia
What is the main dose-limiting toxicity of chemotherapy?
How can you improve it?
Bone marrow failure
Autograft - G-CSF is given –> stem cells are collected from peripheral blood pre treatment –> induction Ctx (to kill cancer) –> reinfused post
How long does the severe pancytopaenia post induction and HSCT transplant last? How is it managed?
7-10 days
Transfusion and antibiotics
When is autografted stem cell transplant used?
DLBCL recurrence after chemo but still responsive to chemo
Responsive relapsed Hodgkin’s lymphoma
Recurred testicular germ cell tumours
What is the role of autologous stem cell transplant in mantle cell lymphoma and multiple myeloma?
Autologous stem cell transplantation is currently part of the standard of care for the treatment of mantle cell lymphoma and multiple myeloma, based not on curative potential, but the prolongation of remission and overall survival.
What are acanthocytes?
What causes them?
Acanthocytes arise from either of two mechanisms. Alterations in membrane lipids are seen in abetalipoproteinemia and liver dysfunction. Alteration in membrane structural proteins are seen in neuroacanthocytosis and McLeod syndrome.
In liver dysfunction, apolipoprotein A-II deficient lipoprotein accumulates in plasma causing increased cholesterol in RBCs. This causes abnormalities of membrane of RBC causing remodeling in spleen and formation of acanthocytes.
What is leucodepletion?
On what is it performed?
What are the benefits?
Leucodepletion is the removal of white blood cells from a blood component.
Applies to whole blood, red cells and platelets.
Benefits:
- Reduction in platelet refractoriness
- Reduction in febrile non-haemolytic transfusion reactions. (FNHTR)
- Reduction in CMV transmission risk
- Improved chance of finding an organ transplant match if required
- Reduction in storage lesion effect
- Possible reduction in transfusion associated graft vs host disease (TA-GVHD) risk
Leucodepletion by filtration of blood for transfusion is most likely to reduce the risk of which one of the following transfusion-associated events in the transfused recipient?
A. Hepatitis C.
B. Citrate toxicity.
C. Cytomegalovirus infection.
D. Malaria.
E. Anaphylactic reaction.
C
A 48-year-old previously well man is receiving a transfusion of four units of packed red cell concentrate via a peripheral intravenous line after presenting with melaena secondary to a bleeding duodenal ulcer. He has not been previously transfused. Admission biochemistry (including urea, electrolytes and creatinine) is normal and pre-transfusion blood counts are normal apart from anaemia (haemoglobin 64 g/L [135-170]). Less than five minutes after transfusion of the third unit of blood is commenced, he complains of feeling very unwell and abruptly develops fever, chills, rigors and profound hypotension.
In the absence of ABO, Rhesus or minor blood group donor-recipient incompatibility, the most likely diagnosis is:
A. bacterial contamination of the transfused blood.
B. transfusion-associated graft-versus-host disease.
C. electrolyte disturbance.
D. citrate toxicity.
E. reaction to plasticiser in infusion bag.
B
What blood can an AB- person receive?
O, A, and B negative blood only
(Negative can only receive negative, never positive)
What blood can an AB+ person receive?
A, B and O all positive or negative
Positive blood groups can receive negative matches.
What blood can an A+ person receive?
A-, A+ or O +/-
(Positive can receive negative or positive)
(O bloods do not have A or B antigens)
What blood can an A- person receive?
A- or O- only
Negative can only receive negative
O does not have A or B antigens but still carries rhesus status.
What blood can an B+ person receive?
B +/-, O+/-
Positive can receive positive or negative
O does not carry A or B antigens, only rhesus status
What blood can an B- person receive?
B- or O- blood.
Negative can only receive negative
O has no A or B antigens, only rhesus.
What blood can an O- and O+ person receive?
O- can only receive O-
O+ can receive both O+ and O-
No A or B can be given because the recipient will have antibodies
Negative can only receive negative
O does not have A or B antigens
How much will 1 unit of PRBCs raise the HCT by?
Approx 4%
When are frozen red blood cells used?
Rare blood types
Occasionally - severe leukoagglutinin reactions or anaphylactic reactions
Why are the A and B antigen important in blood types?
If you lack one, you have an IgM isoantibody to it (isoagglutinin) –> complement gets activated –> rapid intravascular lysis.
Why is type O negative blood used in emergencies?
What needs to be done to it?
It does not have A or B antigens, and thus can be given to anyone.
PRBCs can only be given (the plasma has to be separated out) because the donor plasma contains Anti-A or Anti-B antibodies.
Why is the Rhesus antigen important in blood typing?
Rh D antigen is highly immunogenic
Anyone who receives D+ blood when they are D- will subseuqnetly make highly active anti-D antibodies that cause severe lysis of subsequent transfusions of D+ red cells or to a future rhesus positive baby
Why is anti-D given to rhesus-negative mothers?
Stops allo-immunisation by destroying any Rh-D positive fetal erythrocytes that get through to the maternal system before the mother can make her own antibodies.
Prevents haemolytic disease (rhesus disease) of the newborn.
Okay if you have an RH+ mother and an Rh- fetus
What causes haemolytic transfusion reactions?
Acute
ABO incompatibility - isoagglutinin mediated
Mostly due to clerical errors and mislabelled specimens
Rapid intravascular haemolysis - most severe usually when the patient is under anaesthesia
Delayed
Minor RBC antigen discrepancies, less severe, IgG alloantibody mediates
5-10 days post transfusion
Most common antigens are duffy, Kidd, Kell and Rh C and E
SSx
Fever, chills, backache and headache
Apprehension, dyspnoea and hypotension
Generalised bleeding and oliguria
Severe: DIC, ARF due to ATN
Delayed: usually w/o SSx
Tx - hydration, maybe forced diuresis with mannitol
What is a leukoaggluttinin transfusion reaction?
Leucocyte rich blood products esp platelets cause - happens in 1-2% of transfusion
Fevers and chills within 12 hours post
No haemolysis
Responds to panadol and dipenhydramine, steroids
Less of an issue now with leuco depletion
Different to a hypersensitivity reaction
What is the cause of a blood product hypersensitivity reaction?
Exposure to allogeneic plasma proteins (not leukocytes)
Anaphylactic shock may develop in IgA deficient patients because of IgA antibodies in the plasma component of the donor product.
May require washed or frozen PRBCs next time.
Under what circumstances does contamination of blood products occur?
Platelets especially because they cannot be refrigerated
Gram positive contaimination will cause fever and bacteraemia but rarely sepsis.
Gram negative will cause septic shock, acute DIC and ARF due to transfused endotoxin - usually fatal.
Reduced by
Aseptic technique
Diverting first few ml of donated blood
Single donor products (instead of pooled)
POC bacterial screening to discard dodgy units
Which blood products can transmit viral diseases?
All blood products can.
Risk of post-transfusion viral hepatitis is very low.
Leukodepletion has greatly reduced CMB transmission, possibly equivalent to CMV-screened negative blood products.
What is tranfusion graft-versus-host disease?
Usually fatal, fever, rash, diarrhea, hepatitis, lymphadenopathy and severe pancytopaenia
Usually in patients with immune defects, malignant lymphoproliferative disorders, chemo or immunotherapy, immunosuppression, old patients getting cardiac surgery
HIV alone does not increase risk
Leukodepletion doesn’t avoid, need to irradiate the blood products if high risk.
What is TRALI? What causes it and how does it present?
Transfusion-related Acute Lung Injury
Allogeneic antibodies in donor plasma bind to recipient leukococyte antigens including HLA, granulocyte and monocyte specific.
Definition: Non-cardiogenic pulmonary oedema after a blood product transfusion without other explanation. Surgical and critically ill patients most susceptible.
Reduced with male only plasma, treated with supportive care.
At what platelet level is there a higher risk of spontaneous bleeds?
Life threatening bleeding?
When do you transfuse?
What do you aim for?
<80
<5
Given when less then 10
In thrombocytopaenia pre-op patients, goal is to get the platelet count >50
What are the causes of poor platelet response post transfusion?
Fever, sepsis
Splenomegaly
Lagre habitus
Low platelet dose in transfusion
Platelet alloimmunisation from prior transfusion
Prior pregnancy
Prior organ transplantation
May get alloantibodies directed at HLA antigens - can get HLA matched antigens if this is the case.
