Haematological complications of HIV infection.

South Africa is in the midst of the world's largest human immune deficiency virus (HIV) epidemic with an estimated 5.6 million people infected. Haematological manifestations of HIV are common and diverse, occurring at all stages of infection. Haematological emergencies occurring in this setting include the high-grade lymphomas, particularly Burkitt lymphoma, and thrombotic thrombocytopenic purpura (TTP). Immune thrombocytopenic purpura (ITP), opportunistic infections and drug side-effects are also frequent causes of cytopenias. A bone marrow biopsy has a high diagnostic utility in HIV patients presenting with unexplained cytopenias and/or fevers. It is not widely realised that HIV is also a prothrombotic state with an increased incidence of thromboembolic disease. Highly active antiretroviral therapy (HAART) is now widely available in South Africa and is a crucial adjunct to therapy of haematological complications. Medical professionals across all disciplines need to be alert to the haematological complications of HIV infection.