RECOMBINANT HUMAN GRANULOCYTE-COLONY-STIMULATING FACTOR INCREASES CIRCULATING CD34 POSITIVE CELLS IN PATIENTS WITH AIDS

In a gene therapy-based treatment of AIDS, it would be desirable to ha ve as many transduced target cells as possible. A limiting factor is t he number of target cells. In this study, we investigated whether it w as possible to increase the absolute number of one possible target cel l, i.e., the circulating hematopoietic progenitor cells (CD34 cells) i n patients with AIDS, using the recombinant human granulocyte colony-s timulating factor (G-CSF). Eight patients with AIDS were treated with G-CSF for neutropenia (<1.0 x 10(9)/l). Treatment consisted of daily s ubcutaneous injections with 300 mu g G-CSF for 3-5 consecutive days. W ithin 5 days of initiation of G-CSF therapy, an increase in the absolu te neutrophil count (ANC) was seen in all patients. There was a median increase in ANC from 0.4 to 3.4 x 10(9)/l. In addition, G-CSF treatme nt significantly increased the absolute number of CD34 cells. The medi an increase in CD34 cells was from 0.8 to 2.2 x 10(6)/l. Finally, usin g a highly sensitive HIV-1 RNA PCR, we found that treatment of AIDS pa tients with G-CSF did not lead to enhanced HIV replication. These obse rvations indicate that G-CSF may be used to mobilize CD34 cells in pat ients with AIDS, e.g., for a gene therapy protocol.