The effect of long-term treatment with granulocyte colony-stimulating factor on hematopoiesis in HIV-infected individuals

This randomized, placebo-controlled trial examine the long-term effect of g ranulocyte colony-stimulating factor (G-CSF) on absolute numbers of CD34(+) progenitor cells and progenitor cell function in human immunodeficiency vi rus (HIV)-infected patients. G-CSF (300 mu g filgrastim) or placebo was giv en three times weekly for 12 weeks to 30 HIV-infected patients that had bee n treated with HAART for at least 24 weeks and not yet achieved CD4 counts above 350 CD4(+) cells/mu l. Blood samples were collected at weeks 0, 2, 4, 8, and 12, and again 12 weeks after termination of the G-CSF treatment. Si gnificant increase in absolute numbers of circulating CD34(+) cells was det ected in the treatment group (P = 0.006). The function of progenitor cells was examined in vitro using a colony-forming unit (CFU) assay, and increase in the number of CFU/ml was detected (P = 0.005). In order to estimate the effect of G-CSF on in vivo function of progenitors the white-blood count w as determined. Significant increase in white-blood count was found (P < 0.0 01), while hemoglobin and platelet count decreased (P = 0.001 and P = 0.013 , respectively). Significant increase in the CD4 count occurred, but correl ation between the numbers of progenitors and the CD4 count was not found. T hese data suggest that G-CSF mainly increases the number and differentiatio n of myeloid progenitors.