Granulocyte colony-stimulating factor increases CD4⁺ T cell counts of human immunodeficiency virus-infected patients receiving stable, highly active antiretroviral therapy: Results from a randomized, placebo-controlled trial

Thirty human immunodeficiency virus (HIV)-infected patients with CD4⁺ T cell counts <350 cells/mm³ who had received stable, highly active antiretroviral therapy (HAART) for at least 24 weeks were randomized to receive either placebo or granulocyte colony-stimulating factor (G-CSF; 0.3 mg/mL 3 times a week) for 12 weeks. Blood samples were collected at specified time points. G-CSF treatment enhanced the total lymphocyte count (P = .002) and increased CD3⁺ (P = .005), CD4⁺ (P = .03), and CD8⁺ (P = .004) T cell counts as well as numbers of CD3^-CD16⁺CD56⁺ NK cells (P = .001). The increases in CD4⁺ and CD8⁺ cell counts resulted from increases in CD45RO⁺ memory T cells and cells expressing the CD38 activation marker. Lymphocyte proliferative responses to phytohemagglutinin and Candida antigen decreased, whereas NK cell activity and plasma HIV RNA did not change during G-CSF treatment. After 24 weeks, all immune parameters had returned to baseline values. This study suggests that G-CSF treatment of HIV-infected patients receiving stable HAART increases the concentration of CD4⁺, CD8⁺, and NK cells without inducing changes in the virus load.