Clinical Haematology

Clinical Haematology

1. Iron deficiency anaemia

   • caused by defective synthesis of haemaglobin, resulting in cell that are smaller than normal (microcytic) and contain reduced amounts of haemoglobin (hypochromic)
   • Iron stores comprise ferritin, a labile and readily accessible source of iron, and haemosiderin, an insoluble form found predominately in macrophages.
   • LAB INVESTIGATION
     • FBC, film.
       • Confirm anaemia: reduced Hb conc, reduced mean cell volume (MCV), reduced mean cell Hb, reduced mean cell Hb conc.
         • Reduced Hb late indication of deficiency.
         • Some analysers determine % of hypchromic cells
       • Microcytic hypochromic red cells with pencil cells & target cells.
     • Haematinic assay
       • demonstrate reduced serum ferritin conc in straight forward iron defeciency.
       • as an acute phase protein, serum ferritin conc maybe normal or raised in inflammatory or malignant disease.
         • eg, rheumatoid disease.

2. Macrocytic Anaemia

   • rise in MCV of RBC above normal range
   • causes of macrocytosis fall into 2 groups
     • A) deficiency in vit B12/ folate in which bone marrow is megaloblastic
       • Vit B12 usually due to pernicious anaemia
       • Blood film: oval macrocytes, hypersegmented neutrophil nuclei.
       • Severe case: WBC & platelet count fall (panocytopenia)
     • B) other causes, in which the bone marrow is normoblastic
   • • Serum vitamin B12 assay • Serum and red cell folate assays • Liver and thyroid function • Reticulocyte count • Serum protein electrophoresis • For vitamin B12 deficiency: serum parietal cell and intrinsic factor antibodies, radioactive vitamin B12 absorption with and without intrinsic factor (Schilling test), possibly serum gastrin concentration • For folate deficiency: antigliadin, anti-endomysial and antireticulin antibodies • Serum antigliadin and anti-endomysial antibodies (intrinsic factor Ab & peritenial cell Ab)