Anaemia is a common problem and increases in frequency with stage of HIV infection, ranging from 3% of asymptomatic patients to 12% of patients with CD4+ T cell counts of <200 cells/μL (or a CD4+ T cell percentage of <14% of lymphocytes) and 37% of patients with the acquired immunodeficiency syndrome (AIDS) in one large surveillance study.3 Anaemia has been associated with reduced survival in a number of studies, independent of other risk factors such as CD4+ T cell count and HIV viral load.3,4 The cause for this association has not been determined. This relationship is more pronounced in patients who remain anaemic after commencing cART. 5 Causes of anaemia are often multifactorial. Common causes of anaemia include anaemia of inflammatory disease (previously termed anaemia of chronic disease), drugs such as zidovudine, cotrimoxazole, amphotericin B, ganciclovir, ribavirin and dapsone, and both opportunistic and non-opportunistic infections. Other causes are malignancy (lymphoma and Kaposi’s sarcoma involving the gastrointestinal tract) and hypersplenism (often associated with liver disease such as chronic viral hepatitis). Rarer, important causes include Castleman’s disease, human parvovirus B19 infection, thrombotic thrombocytopenic purpura haemophagocytic syndrome. Anaemia of inflammatory disease may be due to HIV infection, other infections or cancer. Zidovudine and lamivudine may cause a macrocytosis.1,6 Low B12 levels are not uncommon but true B12 deficiency is rare.7 Similarly, while direct antiglobulin tests are often positive, ranging from 18 to 43% of people with HIV infection,8 autoimmune haemolytic anaemia is rare.9
The ideal treatment for anaemia is to identify and manage the underlying cause (e.g. treat HIV or other infections or remove causative drugs). Human parvovirus B19 infection is a rare but interesting cause of pure red cell aplasia in severely immunodeficient patients; it responds to cART and intravenous immunoglobulin therapy.1 If the cause of the anaemia cannot be corrected, then exogenous erythropoietin may improve haemoglobin levels and quality of life.10,11 However, it is not effective in patients with high endogenous levels (>500 IU/L). Treatment with erythropoietin may reduce the risk of mortality while blood transfusion therapy may increase this risk.12,13 Consequently, only patients with symptomatic anaemia without a correctable cause should be considered for transfusion.