Urgent Investigation in Patients with Pancytopenia of Unknown Aetiology
| Test | Rationale |
|---|---|
| Repeat full blood count | To exclude artefactual result (e.g. blood from drip stream, clotted sample) |
| Reticulocyte count | A low reticulocyte count in the context of pancytopenia suggests a defect in the marrow rather than a peripheral consumptive problem |
| Blood film for attention of haematologist | Critical to assess for morphological diagnostic clues (e.g. leukaemic blast cells) |
| Group and save, direct antiglobulin test | In case transfusion is required; the DAT will be positive in autoimmune haemolytic anaemia (e.g. Evans syndrome) |
| Serum B12 and folate | To exclude remediable deficiencies resulting in megaloblastic anaemia |
| Serum ferritin | Likely to be elevated in acute infection/inflammation; grossly elevated in haemophagocytic syndrome |
| ALT, ALP, bilirubin, albumin | May be abnormal in acute hepatitis, EBV and CMV infection; unconjugated hyperbilirubinaemia also seen in haemolysis |
| LDH | Typically elevated in haemolysis, B12 and folate deficiency, high grade lymphoma, hepatitis |
| PT, APTT, fibrinogen | To assess for disseminated intravascular coagulation |
| Acute viral serology (EBV, CMV IgM and IgG) | Potential causes of unexplained acute onset pancytopenia |
| Chronic viral serology (HIV, Hepatitis B/C) | Each can cause pancytopenia; recognized association between hepatitis and marrow aplasia |
| Autoimmune profile | Rare presentation of SLE, and other connective tissue disorders |
| Lipid profile | Elevated triglycerides in haemophagocytic syndrome |
DAT, direct antiglobulin test; ALT, alanine transaminase; ALP, alkaline phosphatase; LDH, lactate dehydrogenase; PT, prothrombin time; APTT, activated partial thromboplastin time; EBV, Epstein-Barr virus; CMV, cytomegalovirus; HIV, human immunodeficiency virus; SLE, systemic lupus erythematosus.