The Use of Hematopoietic Growth Factors in HIV Infection and AIDS-Related Malignancies

Abstract

Human immunodeficiency virus (HIV) infection is associated with multiple defects in immune regulation and hematopoiesis. These defects include decreased proliferation of hematopoietic progenitor cells and increased destruction of mature cells. There are also disturbances of regulatory cytokines. As a result, hematopoietic cytopenias are common and the tolerance of myelosuppressive therapy is poor. One successful approach to the management of these clinical problems is the use of hematopoietic growth factors. To date, three agents have been studied in patients with HIV infection. In a Phase I trial, granulocyte macrophage-colony stimulating factor (GM-CSF) corrected leukopenia and pre-existing neutrophil defects in patients with HIV infection. In uncontrolled trials, GM-CSF also appears to reduce toxicity from zidovudine, ganciclovir, alpha-interferon, and antineoplastic therapy. In a placebo-controlled trial, erythropoietin (EPO) decreased transfusion requirements and corrected anemia in the majority of patients receiving zidovudine. In a Phase I/II trial, granulocyte colony-stimulating factor (G-CSF) also corrected leukopenia and neutrophil defects in patients with AIDS without altering HIV expression. Combined G-CSF and EPO treatment corrected both anemia and leukopenia and reduced zidovudine toxicity. New combinations of hematopoietic stimulants are being used to decrease the toxicity from cytotoxic chemotherapy in the treatment of AIDS-related malignancies. Future treatments with other recombinant cytokines may result in both reduction in myelosuppression from drug therapy and, possibly, reconstitution of the immune and hematopoietic systems of HIV-infected patients.