I85PREP
⌘ K
Egyptian Board Clinical Pathology study materials
Egyptian Board Clinical Pathology study resources

Egyptian Board Clinical Pathology: Haematology and Blood Transfusion Medicine

Egyptian Board Clinical Pathology · Work through your exam, one topic at a time.

All guide sections

Haematology and Blood Transfusion Medicine

Haematology and transfusion questions test the path from a full blood count to a safe component: what the numbers mean, whether the film supports them, whether the coagulation result is real, and whether the unit is compatible.

Core rules

  • Anaemia is classified by MCV plus the reticulocyte response: low reticulocyte count indicates a production defect, high indicates loss or haemolysis.
  • Iron deficiency: low ferritin is the best single test, but ferritin is an acute-phase reactant, so a normal value does not exclude deficiency in inflammation. Anaemia of chronic disease shows low iron, low transferrin and normal or high ferritin.
  • Suspected EDTA-induced platelet clumping must be checked on a film and, if confirmed, repeated in citrate.
  • PT/INR monitors warfarin; APTT monitors unfractionated heparin or an anti-Xa assay. A 1:1 mixing study that corrects immediately suggests factor deficiency; failure to correct suggests an inhibitor; time-dependent correction suggests a factor VIII inhibitor.
  • DIC: thrombocytopenia, prolonged PT and APTT, low fibrinogen, raised D-dimer, schistocytes.
  • ABO/Rh grouping needs concordant forward (cell) and reverse (serum) grouping; a discrepancy must be resolved before issue.
  • Antibody screen and crossmatch are not interchangeable; follow local policy when the screen is negative.
  • Storage: red cells 2–6 °C, platelets 20–24 °C with agitation, fresh frozen plasma at or below –25 °C.
  • Suspected reaction: stop the transfusion, maintain the line with saline, check patient and unit identity first, then investigate.

Worked example

An APTT of 68 s (normal 26–36) corrects to 33 s on immediate mixing and remains corrected at two hours. This indicates a factor deficiency rather than a lupus anticoagulant or a specific inhibitor. The next step is specific factor assays guided by the bleeding history, not simply repeating the APTT.

Traps

  • Reporting cold agglutinin artefact (high MCV with high MCHC) as true macrocytosis.
  • Accepting a reverse group mismatch as clerical without documented resolution.
  • Treating group O red cells as universally compatible for plasma.
  • Missing a delayed haemolytic reaction because the patient only developed anaemia and jaundice days later.