Haematopoietic growth factors as supportive therapy in HIV-infected patients

Neutropenia and anaemia are common problems in patients with HIV infection. Neutropenia can lead to a reduction in drug doses or to withdrawal of important myelosuppressive agents such as ganciclovir, zidovudine, cotrimoxazole and pyrimethamine, while anaemia may require the administration of blood transfusions.

Haematopoietic growth factors such as granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) are effective in the treatment of AIDS-related neutropenia. G-CSF appears to be better tolerated than GM-CSF. Moreover, GM-CSF can stimulate HIV replication in the absence of antiretroviral treatment. Thus G-CSF may offer a better treatment option in some patients. Doses of up to 300 micrograms G-CSF (filgrastim) per day rapidly reverse neutropenia in most HIV-infected patients. Subsequently, normal neutrophil counts can be maintained with intermittent doses (1-7 days a week). This allows greater use of myelosuppressive agents. Recombinant human erythropoietin is well tolerated and effective in the treatment of anaemia due to zidovudine when endogenous erythropoietin levels are < or = 500 IU/l. Recombinant human erythropoietin combined with CSF also appears to be well tolerated and effective in the treatment of combined cytopenias. Other haematopoietic growth factor combinations are currently being explored.

CSF and recombinant human erythropoietin, used alone or in combination, appear to be well tolerated and effective in the treatment of neutropenia and anaemia, respectively, in patients with HIV infection. G-CSF may be preferable to GM-CSF in some patients. However, the advantages of therapy with haematopoietic growth factors have to be balanced against the disadvantages of cost, inconvenience and discomfort associated with repeated subcutaneous injections. At present there is no clear evidence that CSF prolongs the survival of AIDS patients.