Steven A. Miles, MD

Anemia is a common complication of HIV infection. Erythropoietin (Procrit, Epogen) can correct anemia. When given to patients with HIV infection, erythropoietin ameliorates anemia and improves quality of life. Given these three facts, one wonders why an effective drug such as erythropoietin is not used appropriately in patients with HIV infections.

The article by Hambleton provides a compendium of the causes of hematopoietic defects in HIV-infected individuals. For the busy practicing physician who treats patients with HIV, these defects are not trivial. Cytopenias are a continuous problem that impact on most clinical decisions. For example, anemia and neutropenia are more common in patients with 100 CD4 cells/mcL or less. In general, these patients also have the highest titers of virus and are at greatest risk of developing symptomatic Mycobacterium avium or cytomegalovirus infection. Thus, physicians often find themselves trying to decide which patients should undergo a more extensive evaluation and which should receive "less" myelosuppressive therapy.

The occurrence of Kaposi's sarcoma (KS) in patients with HIV infection is more than 7,000 times higher than in the non-HIV infected population. The reason for this association is unclear but may involve decreased immune surveillance as a result of the profound cellular immune deficiency caused by HIV, a sexually transmitted KS-inducing virus, whose KS-transforming capabilities may be enhanced by HIV, or a direct or indirect effect of HIV itself in susceptible individuals.