Hematopoietic growth factors as adjuncts to antiretroviral therapy

Abstract

Anemia and neutropenia are common complications of HIV infection. Antiretroviral therapy with zidovudine exacerbates bone marrow suppression by inhibiting proliferation of blood cell progenitor cells. In addition, treatment for opportunistic infections or malignancies can involve the use of myelosuppressive drugs. As a consequence, severe anemia and neutropenia can result, thereby limiting the utilization of antiretroviral drugs. Since antiretroviral therapy can increase survival, drugs that ameliorate myelosuppression are important adjuncts in the treatment of HIV-infected patients. Three hematopoietic growth factors are effective in the treatment of anemia or neutropenia. In four placebo-controlled trials, erythropoietin (EPO) at doses up to 600 U/kg/wk decreased mean transfusion requirements by 37%, increased mean hematocrit by 4.5% and corrected anemia in the majority of patients receiving zidovudine over a 12-week period. In a separate study, granulocyte colony-stimulating factor (G-CSF) corrected leukopenia and isolated neutrophil defects in 22 patients with AIDS without altering HIV expression. When erythropoietin was added to the regimen, combined G-CSF and EPO corrected both anemia and leukopenia and lessened subsequent zidovudine toxicity. Similarly, granulocyte macrophage-colony-stimulating factor (GM-CSF) corrected leukopenia and pre-existing neutrophil defects in patients with HIV infection. In controlled and uncontrolled trials, GM-CSF also appears to reduce toxicity from zidovudine, ganciclovir, and antineoplastic therapy. New combinations of hematopoietic stimulants are being used to decrease the toxicity from combination antiretroviral therapy with alpha interferon and cytotoxic chemotherapy in the treatment of AIDS-related malignancies.(ABSTRACT TRUNCATED AT 250 WORDS)