Haematology Flashcards
IRON DEFICIENCY ANAEMIA
What is the physiology of iron?
- Bone marrow requires iron to produce Hb which is mainly absorbed in the duodenum + proximal jejunum enhanced by vitamin C + inhibited by tannin (tea)
IRON DEFICIENCY ANAEMIA
What are some causes of iron deficiency anaemia?
- Increased loss = menorrhagia, GI bleeding (?colorectal cancer), hookworm
- Inadequate intake/increased needs = poor diet, puberty growth, pregnancy
- Malabsorption = IBD, coeliac disease
IRON DEFICIENCY ANAEMIA
What is the clinical presentation of iron deficiency anaemia?
- Symptoms = fatigue, SOB, headaches, dizziness, palpitations
- Generic signs = (conjunctival) pallor, tachycardia + tachypnoea
- Pica = consumption of non-food materials
- Koilonychia, angular stomatitis, atrophic glossitis + brittle hair/nails
IRON DEFICIENCY ANAEMIA
What investigations would you do in iron deficiency anaemia?
- FBC = low Hb, low MCV + normal reticulocytes
- Blood film = hypochromic microcytic RBCs, target cells + pencil poikilocytes
- Iron studies
- ?2ww suspected colorectal cancer for colonoscopy if ≥60
IRON DEFICIENCY ANAEMIA
What would iron studies show in iron deficiency anaemia?
- Low = ferritin, iron + transferrin saturation (proportion of transferrin bound to iron)
- High = total iron binding capacity (total space on transferrin for iron to bind)
IRON DEFICIENCY ANAEMIA
What is the management of iron deficiency anaemia?
Side effects of the treatment?
- Diet = red meat, oily fish, green veg (broccoli, spinach), dried fruit (raisins)
- PO iron supplementation (ferrous sulfate/fumarate)
- Note SE: constipation, black coloured stools, nausea + abdo pain
THALASSAEMIA
What is thalassaemia?
What is the epidemiology?
- Autosomal recessive disorders caused by ≥1 gene defect, resulting in a reduced rate of production of ≥1 alpha/beta globin chains making RBCs more fragile
- Common in Mediterranean, Middle East + East Africa
THALASSAEMIA
How is alpha thalassaemia classified?
- 1–2 alpha globin alleles affected = hypochromic + microcytic but Hb often ok
- 3 = hypochromic microcytic anaemia with splenomegaly (Hb H disease)
- 4 = death in utero due to foetal hydrops
THALASSAEMIA
How is beta thalassaemia classified?
- Minor = 1 abnormal and 1 normal gene
- Intermedia = 2 defective or 1 defective + 1 deletion
- Major = homozygous for deletion genes
THALASSAEMIA
What is the clinical presentation of beta thalassaemia…
i) minor?
ii) intermedia?
i) Mild microcytic anaemia which only needs monitoring
ii) Jaundice + hepatosplenomegaly, monitoring ± blood transfusions
THALASSAEMIA
What is the clinical presentation of beta thalassaemia major?
- Presents in first year with failure to thrive, hepatosplenomegaly, jaundice, microcytic anaemia
- Extramedullary haemopoiesis = hepatosplenomegaly, bone marrow expansion (maxillary overgrowth + frontal bossing)
- HbA2 + HbF raised but HbA absent
THALASSAEMIA
What investigations would you do in thalassaemia?
How do you differentiate from iron deficiency anaemia?
What investigation is diagnostic?
- FBC = low Hb + MCV
- Film = hypochromic + microcytic RBCs
- Serum ferritin NORMAL
- Hb electrophoresis = diagnostic
- DNA testing via CVS
THALASSAEMIA
What is the management of thalassaemia?
What is a complication of this and how is it managed?
- Blood transfusions (regular in beta thalassaemia major)
- Require iron chelation with desferrioxamine to avoid overload + organ failure (cardiomyopathy, cirrhosis, DM, arthritis)
- Splenectomy ± curative bone marrow transplant
B12 DEFICIENCY ANAEMIA
What is the physiology of vitamin B12?
- Absorption occurs in the terminal ileum + is intrinsic factor (secreted by gastric parietal cells) dependent for transport across the intestinal mucosa
B12 DEFICIENCY ANAEMIA
What are some causes of B12 deficiency anaemia?
- Malabsorption = Crohn’s, coeliac, ileal resection
- Dietary (vegans) as B12 high in fish, meat, dairy
- Autoimmune (pernicious) = atrophic gastritis leads to destruction of parietal cells > intrinsic factor deficient
B12 DEFICIENCY ANAEMIA
What is the clinical presentation of B12 deficiency anaemia?
- Anaemia Sx = fatigue, SOB, headaches, dizziness, palpitations
- B12 deficiency = dorsal column affected (proprioception, loss of vibration, peripheral neuropathy paraesthesia, neuropsych mood disturbance), glossitis (beefy-red sore tongue)
B12 DEFICIENCY ANAEMIA
What investigations would you do in B12 deficiency anaemia?
- FBC = low Hb, high MCV (macrocytic, megaloblastic)
- Haematinics = low B12
- Blood film = hypersegmented neutrophil nuclei
- Intrinsic factor Ab specific for pernicious, may have gastric parietal cell Ab
B12 DEFICIENCY ANAEMIA
What are some differentials of macrocytic anaemia which are normoblastic?
- Alcohol
- Liver disease
- Hypothyroidism
- Myelodysplasia
- Reticulocytosis
B12 DEFICIENCY ANAEMIA
What should you check before managing B12 deficiency anaemia?
What is the management of B12 deficiency anaemia?
- Folate > do not give folic acid as can cause subacute combined degeneration of the cord = distal sensory loss, ataxia + mixed U/LMN signs
- Initially IM hydroxocobalamin then maintenance with PO cyanocobalamin if diet-related or IM hydroxocobalamin every 2–3m
FOLATE DEFICIENCY ANAEMIA
What is the pathophysiology of folate deficiency anaemia?
- Develops over 4m of deficiency due to bodily reserves
- Folate is absorbed in the proximal jejunum
FOLATE DEFICIENCY ANAEMIA
What are some causes of folate deficiency anaemia?
- Increased demand = pregnancy, malignancy, haemolysis
- Decreased intake = poor diet (green vegetables)
- Decreased absorption = coeliac, Crohn’s, jejunal resection
FOLATE DEFICIENCY ANAEMIA
What is the clinical presentation of folate deficiency anaemia?
- Anaemia = fatigue, SOB, headaches, dizziness, palpitations
- NO neuropathy
FOLATE DEFICIENCY ANAEMIA
What investigations would you do in folate deficiency anaemia?
What’s the management?
- FBC = low Hb, high MCV, macrocytic megaloblastic
- Haematinics = low folate
- PO folic acid 5mg OD
HEREDITARY SPHEROCYTOSIS
What is the pathophysiology of hereditary spherocytosis?
- Autosomal dominant mutation of structural RBC membrane proteins leading to removal of abnormal membrane as it passes by spleen resulting in reduced SA:V + becoming spheroidal leading to extravascular haemolysis + destroyed by spleen
HEREDITARY SPHEROCYTOSIS
What is the epidemiology and clinical presentation of hereditary spherocytosis?
- Most common inherited haemolytic anaemia in Northern Europeans
- Anaemia, jaundice, splenomegaly + gallstones (due to increased bilirubin excretion)
HEREDITARY SPHEROCYTOSIS
What are the investigations for hereditary spherocytosis?
- FBC = raised MCHC, raised reticulocytes
- Film = spherocytes (no central pallor) + schistocytes (haemolysis)
- EMA binding test = diagnostic
HEREDITARY SPHEROCYTOSIS
What complication can occur in hereditary spherocytosis and why?
How does it present?
What is the management?
- Aplastic crisis due to parvovirus B19 infection
- Increased anaemia, extravascular haemolysis + jaundice without normal bone marrow (reticulocyte) response to create new RBCs
- Supportive, ?transfusion
HEREDITARY SPHEROCYTOSIS
What is the management of hereditary spherocytosis?
- PO folate replacement
- Splenectomy before 5y is curative > Hib, Men A + C, annual influenza, PCV 5 yearly, PO pen V for at least 2y
G6PD DEFICIENCY
What is G6PD deficiency?
- X-linked recessive haemolytic anaemia so predominantly affects males, more common in Mediterranean, Middle Eastern + African background
G6PD DEFICIENCY
What is the clinical presentation of G6PD deficiency?
- Neonatal jaundice often within 3d
- Anaemia, intermittent jaundice, splenomegaly + gallstones
G6PD DEFICIENCY
What investigations would you do in G6PD deficiency?
What is diagnostic?
What considerations would you take?
- Blood film = Heinz bodies + bite & blister cells
- Diagnostic = G6PD enzyme assay
- 3m after acute episode of haemolysis as RBCs with most severely reduced G6PD activity will have haemolysed so false negative results
G6PD DEFICIENCY
What is a complication of G6PD deficiency?
What can trigger it?
How does it present?
- Acute (intravascular) haemolysis
- Infection, fava bean, henna + drugs (antimalarials primaquine, sulfa-drugs, ciprofloxacin)
- Fever, malaise, dark urine (Hb + urobilinogen)
G6PD DEFICIENCY
What is the management of G6PD deficiency?
- Avoid precipitants
- ?Transfusion if needed
SICKLE CELL DISEASE
What is the pathophysiology of sickle cell disease?
- Autosomal recessive condition leads to amino acid substitution of glutamine > valine causing abnormal HbS variant
- This polymerises when deoxygenated into sickle shape making them more fragile (haemolysis) + prone to getting trapped in microvasculature (thrombosis) leading to ischaemia/infarction
SICKLE CELL DISEASE
What are the different phenotypes in sickle cell disease?
What is the epidemiology and why is this significant?
- Heterozygous = trait, homozygous = disease
- More common in African descent in areas traditionally affected by malaria as having sickle-cell trait reduces severity of falciparum malaria making them more likely to survive + pass the gene on
SICKLE CELL DISEASE
What is the general clinical presentation of sickle cell disease?
- HbF unaffected so usually manifests when HbF decreases around 6m
- All have moderate anaemia with detectable jaundice from chronic haemolysis
SICKLE CELL DISEASE
What are the various acute presentations of sickle cell disease?
- Vaso-occlusive painful crises
- Sequestration crises
- Aplastic crises
- Acute chest syndrome
SICKLE CELL DISEASE
What is the clinical presentation of…
i) sequestration crises?
ii) aplastic crises?
i) Pooling of blood in spleen leads to severe anaemia + shock, if >2x = splenectomy
ii) Parvovirus B19 = acute sudden anaemia
SICKLE CELL DISEASE
What can cause vaso-occlusive painful crises?
How do they present?
- Triggers = cold, infection, dehydration
- Affects bones of limbs + spine, can lead to avascular necrosis
- Hand-foot syndrome = dactylitis
SICKLE CELL DISEASE
What is the clinical presentation of acute chest syndrome?
What are some potential causes?
- Pleuritic chest pain, fever, SOB, CXR = pulmonary infiltrates
- Infective or non-infective (pulmonary vaso-occlusion, fat emboli)
SICKLE CELL DISEASE
What are the investigations for sickle cell disease?
What is the definitive diagnostic investigation?
- Prenatal Dx with CVS and detected on neonatal heel prick test at 5d
- FBC = normocytic anaemia, high reticulocytes
- Blood film = sickled RBCs, Howell-Jolly bodies + schistocytes
- Definitive = Hb electrophoresis showing high HbSS + absent HbA
SICKLE CELL DISEASE
What are some long-term complications of sickle cell disease?
- Short stature + delayed puberty
- Hyposplenism due to sequestration + infarction so increased infection risk
- Stroke
- Chronic renal failure
SICKLE CELL DISEASE
What is the management of acute crises in sickle cell disease?
- PO/IV analgesia titrate to effect, IV fluids, oxygen, ?NIV
- Infection = Abx
- Blood transfusion if severe anaemia
- Exchange transfusion if severe (e.g., neuro complications)
SICKLE CELL DISEASE
What is the chronic management of sickle cell disease?
- PO hydroxyurea to increase HbF levels as prophylaxis for painful crises
- PCV vaccine every 5y, may have prophylactic pen V
- Bone marrow transplantation curative + offered if failed response
HAEMOLYTIC ANAEMIA
What is the pathophysiology of haemolytic anaemias?
- Extravascular = RBC destruction within reticuloendothelial system (spleen + liver) > sickle cell, hereditary spherocytosis
- Intravascular = RBC destruction within blood stream so release of contents into circulation > G6PD, AIHA, paroxysmal nocturnal haemoglobinuria
HAEMOLYTIC ANAEMIA
How are the causes of haemolytic anaemias split?
Inherited –
- Hereditary spherocytosis, G6PD, sickle cell disease
Acquired –
- Immune coombs +ve = autoimmune or alloimmune (transfusion reactions)
- Non-immune = paroxysmal nocturnal haemoglobinuria, microangiopathic haemolysis
HAEMOLYTIC ANAEMIA
What is the typical biochemical picture seen in haemolysis?
How does this differ between intravascular and extravascular?
- Both = increased unconjugated bilirubin, LDH + reticulocytes
- Intravascular = haemoglobinuria + decreased haptoglobin which binds to free Hb in blood (not seen in extravascular)
HAEMOLYTIC ANAEMIA
What are the 2 types of autoimmune haemolytic anaemia?
- Warm = IgG mediated extravascular haemolysis where spleen tags cells for splenic phagocytosis occurring at body temp
- Cold = IgM mediated where IgM fixes complement causing direct intravascular haemolysis (cold agglutinins) occurring in cold <4 degrees
HAEMOLYTIC ANAEMIA
What are the causes of warm and cold autoimmune haemolytic anaemia?
- Warm = idiopathic, lymphoproliferative neoplasms (CLL, lymphoma), SLE
- Cold = idiopathic, mycoplasma, EBV
HAEMOLYTIC ANAEMIA
What is the clinical presentation of warm and cold autoimmune haemolytic anaemia?
- Warm = jaundice, splenomegaly
- Cold = acrocyanosis, Raynaud’s
HAEMOLYTIC ANAEMIA
What is the management of warm and cold autoimmune haemolytic anaemia?
- Warm = steroids, rituximab or splenectomy
- Cold = keep warm (?blood warmers)
HAEMOLYTIC ANAEMIA
What are the features of paroxysmal nocturnal haemoglobinuria?
What is the management?
- Early adulthood nocturnal episodes of intravascular haemolysis > anaemia, dark urine (haemoglobinuria) in morning
- Flow cytometry diagnostic, eculizumab
HAEMOLYTIC ANAEMIA What is microangiopathic haemolytic anaemia? What causes it? How does it present? What's the management?
- Mechanical destruction of RBCs
- TTP, HUS + DIC
- Fever, renal failure, abdo pain, schistocytes on blood film
- Plasma exchange to remove vWF multimers
ALL
What is acute lymphoblastic leukaemia (ALL)?
What is the epidemiology?
What are some risk factors?
- Abnormal proliferation of lymphoid progenitor cells (usually B-lymphocytes)
- Accounts for 80% of leukaemia in children + peaks at 2–5y
- Trisomy 21 + immunocompromised
ALL
What is the general clinical presentation of ALL?
What causes the various clinical presentations of ALL?
- Fever, weight loss, night sweats, lymphadenopathy
- Infiltration with leukaemic blast cells > bone marrow (pancytopaenia), reticuloendothelial, other organs
ALL
How does ALL present in terms of…
i) bone marrow infiltration?
ii) reticuloendothelial infiltration?
iii) other organ infiltration?
i) Anaemia (pallor, lethargy, SOB), neutropaenia (infection) + thrombocytopaenia (bruising, petechiae, epistaxis)
ii) Hepatosplenomegaly
iii) CNS (CN palsies), bone pain, testicular swelling
ALL
What investigations would you do in ALL?
What is diagnostic?
- FBC + blood film = pancytopaenia, blast cells
- CXR if ?mediastinal mass, LP if ?CNS involvement
- Bone marrow examination via ASPIRATION = diagnostic
ALL
What are some complications of ALL?
- CNS development
- Growth impact
- Infertility
- Cardiac + renal toxicity
ALL
What is the management of ALL?
What are good prognostic factors in ALL?
- Supportive = IV fluids, transfusions, allopurinol to protect kidneys from tumour lysis syndrome
- Chemo = remission, consolidation & CNS protection + maintenance
- Ages 2–10, female, WCC <20, no CNS disease, Caucasian
AML
What is acute myeloid leukaemia (AML)?
- Neoplastic proliferations of myeloid precursor cells
- Commonest acute leukaemia in adults, over 75y affected
AML
What are some causes of AML?
- Myelodysplastic + myeloproliferative syndromes
- Radiation + chemotherapy
AML
What is the clinical presentation of AML?
- Bone marrow failure (pancytopaenia) = anaemia, neutropaenia + thrombocytopaenia
- Infiltration = lymphadenopathy, hepatosplenomegaly + gum hypertrophy
AML
What are the investigations for AML?
What is diagnostic?
- FBC = pancytopaenia, may present in DIC
- Blood film = blast cells + auer rods
- Bone marrow examination via ASPIRATION diagnostic
AML
What is the management of AML?
- Supportive = IV fluids, transfusions, allopurinol
- Chemotherapy or bone marrow transplant but generally poor prognosis
CLL
What is CLL?
What is the epidemiology?
- Monoclonal proliferation of functionally incompetent malignant B cells
- Most common in those >60y
CLL
What is the clinical presentation of CLL?
- Often none but incidental lymphocytosis on FBC
- Anaemia, hepatosplenomegaly + B symptoms (weight loss, fever, night sweats)
CLL
What are the investigations for CLL?
- FBC = anaemia + lymphocytosis
- Blood film = smudge/smear cells
- Immunophenotyping (flow cytometry) diagnostic
CLL
What are the complications of CLL?
- Richter transformation to high grade lymphoma = CLL > large B cell lymphoma
- Hypogammaglobulinaemia
- Warm autoimmune haemolytic anaemia