Haem 2.69-2.76 Flashcards
Nail changes in IDA?
Koilonychia
Reticulocytes and MCV?
Immature red cells; a marker of BM function. Very high levels (reticulocytosis) when red cells are being lost e.g. haemolytic anaemia/bleeding. Larger so push up MCV. May be low in deficiencies or BM failure (chemotherapy, aplastic anaemia)
Four causes of normocytic anaemia?
Anaemia of chronic disease (vasculitis, malignancy), renal failure, mixed anaemia, MYELOMA
Ferritin?
Low usually diagnostic of IDA; moderate/high less helpful as can just be inflammation. Very high may be haemochromatosis.
TIBC/transferrin?
TIBC is indirect measure of transferrin. Blood’s capacity to bind iron. High in pregnancy and IDA to maximise binding; low in anaemia of chronic disease as less transferrin (and more ferritin) produced
Transferrin sat?
Normal in anaemia of chronic disease, low in IDA (not enough Fe), low in pregnancy because more transferrin produced
Serum Fe?
Highly variable, but low in IDA, low in anaemia of chronic disease (because held IC in ferritin instead), normal in pregnancy
Gene most commonly affected in haemochromatosis?
HFE
Features of haemochromatosis?
Diabetes (iron stored in B cells), cardiomyopathy, pituitary failure/hypogonadism, arthritis (chondrocalcinosis), bronzed skin, liver cirrhosis
Causes of secondary (aquired) haemochromatosis?
Severe chronic haemolysis, multiple frequent blood transfusions, excess dietary iron/parenteral iron
Four causes of “decreased production” anaemia?
Haematinics deficiency, anaemia of chronic disease, bone marrow failure, epo deficiency (renal failure)
Two main causes of “increased destruction” anaemia?
Haemolysis (AI, sickle cell, G6PD, hereditary spherocytosis), bleeding
Tests when investigating anaemia?
FBC (MCV); do haematinics. If normal, may be increased destruction. Do LFTs (increased bilirubin), blood film (reticulocytes/blasts), DAT = direct antiglobulin test; looks for Abs bound to RBCs, haptoglobin levels (low in haemolysis)
What is haptoglobin?
Protein that binds to free Hb released from cells. In Intravascular haemolysis, Hb escapes, haptoglobin binds (so levels drop) and then complex removed in spleen, causing splenomegaly.
What is myeloma?
Clonal plasma cell neoplasm; produces monoclonal Ab or fragments of Ab.
Features of myeloma?
Hypercalcaemia (lytic lesions), renal impairment (Abs deposited in epithelium), anaemia (usually normocytic, renal impairment and BM dysfunction), bony pain (lytic lesions). High risk of cord compression. “CRAB”. Also may see raised ESR, high total protein with normallow albumin, low WCC.
Myeloma pathology?
Cytokines lead to increase bone resorption/decreased formation and hypercalcaemia. M proteins/light chains cause renal failure. Deregulated apoptosis/BM invasion/cytokines leads to decreased RBCs/WBCs
Investigating myeloma?
Do serum free light chains; see elevation/abnormal ratio. Also do plasma electrophoresis; see monoclonal band at one weight (ie M protein/paraprotein band) and probable reduction in other Ig. Do bone marrow biopsy (clonal plasma cells >10%). Skeletal survery (X-ray/MRI) for lytic lesions. Likely to be rouleaux on blood film (reflects raised ESR)
Actual diagnosis of multiple myeloma?
- BM biopsy >10% clonal plasma cells
- Presence of paraprotein in serum/urine
- End organ damage (CRAB).
Need 3/3.
Most common paraprotein?
Mostly IgG, some IgA, rest are light chains only
What are Bence-Jones proteins?
Free light chains in the urine; seen in 2/3 multiple myeloma cases
Causes of raised white cells?
Reactive, primary marrow problem e.g leukaemia
Considerations in thrombocytopenia?
Are they well/unwell, bleeding. Check coag and repeat FBC. NB: clumping on film can be artefact cause of “thrombocytopenia”.
Causes of low platelets?
- Decreased production (haematinic deficiency, bone marrow failure [leukaemia etc.], rare hereditary causes)
- Increased destruction (sepsis, DIC, immune (ITP, TTP, HUS, SLE, APS, hypersplenism))
Causes of thrombocytosis? (Vast majority are acquired)
- Essential/primary (ET, PV, CML, MF) i.e. myeloproliferative disorders. Can be separatated into Philadelphia +ve (CML) and -ve.
- Reactive (infection/inflammation/surgery/IDA, haemorrhage)
Difference between polycythaemia and erythrocytosis?
Poly is increased number of red cells; erythrocytosis is increase in red cell mass
Essential thrombocythaemia/cytosis?
One of the four myeloproliferative disorders. Isolated rise in platelets. Usually asymptomatic. Exclude reactive cause. Blood film may show megakaryocytes. Test JAK2/MPL/calreticulin; positive is usually enough for diagnosis. If negative, do biopsy (look for AML/primary myelofibrosis).
Treating ET?
Aspirin (risk of clotting) +/- cytoreduction with hydroxycarbamide
Investigating polycythaemia?
See if primary (myeloproliferative) or secondary (smoking, altitude, epo tumour/injections, sleep apnoea). Do HCT, ferritin, epo, film, JAK2 (+ve in 95% PV).
Polycythaemia vera?
Myeloproliferative; primary cause of polycythaemia. JAK2 +ve in 95%. Get itch/sweats/splenomegaly/gout/plethora; risk of CVA/MI/DVT. Raised RBCs and HCT; platelets and WBCs may be elevated. Splenomegaly can be part of diagnostic criteria.
What are the myeloproliferative and lymphoproliferative disorders?
- Myelo = PV, ET, CML, MF. They are related/may evolve to AML and myelodysplastic syndrome.
- Lympho = ALL, CLL, lymphoma, myeloma etc.
Treating polycythaemia vera?
Aspirin, VENESECTION is mainstay, mild chemo (hydroxycarbamine)
Key difference between primary and secondary polycythaemia?
Epo low in PV (JAK2 allows independence from epo) while high in the others (hypoxia mediated).
High and low Hb?
Low = do MCV; high = ferritin, JAK2, epo levels etc. to look for PV.
Primary myelofibrosis?
Another myeloproliferative disorder. Present with sweats, splenomegaly, progressive pancytopenias (ie anaemia sx, bleeding, infection) as get proliferation of abnormal cell clone causing replacement of haematopoetic tissue with fibrosis. 5 years life expectancy. Diagnosed on BM biopsy.
Primary vs secondary myelofibrosis?
Primary = ‘de novo’; secondary progresses from ET/PV etc.
Why get massive splenomegaly/hepatomegaly in MF?
Extramedullary haematopoeisis; occurs in liver/spleen; get abnormal tear-drop poikilocytes.
Treatment of MF?
Symptomatic (e.g. splenectomy), cytoreduction, JAK2 inhibitor, HSCT.
Genes linked with MF?
JAK2, PML, calreticulin.
CML?
Myeloproliferative. Present with raised WCC, symptoms of hepatosplenomegaly, RUQ pain. +/- fever, sweats. Can present with leukostasis (WBC>100); get blurred vision, headaches as cells clump [ischaemia and haemorrhage]. Caused by proliferation of mature granulocytes and their precursors.
Diagnosing CML?
Peripheral blood count/appearance, (BM biopsy) and cytogenetics. In peripheral blood, may see low/normal/high platelets, normocytic anaemia, high WCC, early myeloid cells, leukoerythroblastosis. Bone marrow is more to rule out acute leukaemia.
Stages of CML to be diagnosed in?
- Chronic stage; sweats, weight loss, hepatosplenomegaly but usually asymptomatic.
- Accelerated; bleeding, petechiae, ecchymoses; fever (now due to infection not increased metabolism).
- Blast phase (like acute leukaemia)
Cause of CML?
Translocation of 9:22 chromosomes to give “Philadelphia c’some”; novel gene is BCR-ABL; resulting novel TK causes proliferation.
Treating CML?
TKI (imatinib, dasatinib (can cause pleural effusion), PCR monitoring for disease level. Can do HSCT. Very treatable.
Managing IDA?
If Hb below ~7, can consider RBC transfusion. Give oral iron or IV iron if more severe. Get constipation and black stool.
Causes of chondrocalcinosis?
Gout, pseudogout, hypercalcaemia, Wilson’s, haemochromatosis, osteoarthritis
Investigating haemochromatosis?
Transferrin sat %, ferritin (if low ferritin, diagnosis unlikely), genotype (HFE), liver biopsy.
Alcohol and anaemia?
Toxic to bone marrow in excess; get fewer, structurally abnormal precursors to RBCs hence macrocytic anaemia. Chronic excess may be linked with folate deficiency “malnutrition of alcohol”; gives megaloblastic red cells and low platelets (myeloid precursors ie also need folate) hence bleeding risk.
Investigating apparent B12 deficient anaemia?
Serum B12, Ab to IF (PA). Rx = B12 injection. Could also be low folate although this is less common.
Causes of B12 deficiency?
- Poor intake (alcohol, vegan diet)
- Poor gastric activation (PPI, gastroenteritis)
- Poor absorption (coeliac, PA, ileal resection, Crohn;s, chronic diarrhoea).
Baseline bloods in haemorrhage?
FBC, group and save, clotting (inc fibrinogen).
What does cryoprecipitate contain?
Factor VIII (haemophilia), fibrinogen, factor XIII, vWF. Essentially is concentrate of FFP and is suitable for use as a volume expander.
What is INR a measure of, essentially?
PT
Causes of haemolytic anaemia? NB: will often see reticulocytosis to compensate.
- Intrinsic (hereditary) = hereditary spherocytosis (membrane defect), defective Hb (sickle cell, thalassaemia), defective red cell metabolism (G6PD/pyruvate kinase deficiency), PNH.
- Extrinsic (acquired) = immune e.g. AIHA, hypersplenism.
Hereditary spherocytosis?
Abnormal red cell membrane; cells are mostly functional but spleen destroys them. Get increased bilirubin (hence pigmented gallstones), increased LDH. Splenectomy is treatment. Get jaundice, HA, splenomegaly, fatigue.
Suspect mixed anaemia?
Do red cell distribution width; wide = mixed.
Tumours associated with raised epo?
HCC, renal cell carcinoma, haemangioblastoma
COPD and polycythaemia?
May be plethoric; indication for home o2.
Platelets in CML?
May be high/normal/low; can drop in accelerated phase to give bleeding/petechiae.
Factors in extrinsic pathway?
Only VII; vit K dependent hence why warfarin primarily increases PT.
Intrinsic pathway factors?
VIII, IX, XI, (XII). APTT.
Vit K dependent factors?
10, 9, 7, 2.
Key features of bleeding history?
Family history, easy bruising, gum bleeding, prolonged bleeding from minor wounds, menorrhagia/post partum bleeding, post op bleeding/need for transfusion/return to theatre.
Investigating child with haemarthrosis and long APTT?
FBC normal. Intrinsic problem. Do correction study (ie mix with normal plasma); if corrects then is factor deficiency. If not then lupus antibody. Do factor assay; here is very low VIII (Haemophilia A).
Severity of haemophilia A?
Different mutations can cause it; get different levels of residual active factor VIII. <1% = severe; 1-5% mod; 5-40% = mild.
Significance of low VIII?
Not needed for initiation, but key for amplification/propagation so cannot generate stable clot.
Haemophilia A?
Most severe bleeding disorder. Usually X-linked recessive (can get mild phenotype in heterozygous girls). Get easy bruising, palpable haematomas. Bleed into weight-bearing joints and muscles; can get degenerative joint disease. Treat with recombinant factor VIII.
Diagnosing haemophilia A?
Differentials are haemophilia B and VWD. Diagnosis based on low levels of VIII assay. Genetics help with risk of transmission etc. Expect long APTT with normal PT.
Haemophilia A management?
Recombinant FVIII, synthetic ADH (DDAVP) in mild promotes endothelial release of FVIII via VWF, analgesia/physio/immobilisation/education.
Drugs to avoid in Haemophilia A?
Aspirin, NSAIDs, heparin.
Haemophilia B?
Mutation in factor IX; low levels. Less common than A. AKA Christmas disease. APTT high; PT normal. Do correction study. X linked, recessive. Treat with IV recombinant factor IX; longer t1/2 than VIII so done less frequently. Same presentation.
Transexamic acid in haemophilia?
Antifibrinolytic; can be useful for surgery/prophylaxis etc.
VWD?
AD inheritance. Low vWF. Present with easy bruising post of bleeding, menorrhagia, mucocutaneous bleeding. Commonest inherited bleeding problem.
Functions of vWF?
- Binds platelets to subendothelium
- Binds platelets to each other
- Binds and stabilises FVIII.
Why is APTT long and FVIII low in VWD?
vWF binds and transports FVIII!
Investigating VWD?
PT normal; APTT may be prolonged. Do VWF assay for quantity and quality! As normal levels present in type 2.
Types of VWD?
- Mild quantitative defect. Usually asymptomatic. AD
- Qualitative defect; can be harder to detect. AD
- Severe quantitative defect. AR!
(Also get acquired and platelet-type [non-hereditary]).
Elevated VWF?
Thrombosis risk factor! In TTP, get defect in enzyme that cleaves vWF. Prone to arterial thrombosis.