Immunomodulatory Treatment of Mycobacterium avium Complex Bacteremia in Patients with AIDS by Use of Recombinant Granulocyte-Macrophage Colony-Stimulating Factor

Abstract

Eight AIDS patients with Mycobacterium avium complex (MAC) bacteremia were randomized to receive azithromycin with or without granulocyte-macrophage colony-stimulating factor (GM-CSF) for 6 weeks to examine the effect of GM-CSF administration on clearance of mycobacteremia and on monocyte function. Superoxide anion production was significantly increased ex vivo in monocytes from patients receiving GM-CSF but not in those from patients receiving azithromycin alone. Relative to monocytes obtained from untreated healthy controls, median differences in viable intracellular MAC at 2, 4, and 6 weeks were −0.76, −0.94, and −0.47 log₁₀ cfu/mL of lysate for cells from patients receiving GM-CSF versus −0.15, −0.11, and −0.19 log₁₀ cfu/mL for cells from patients receiving azithromycin alone. Although no effect on mycobacteremia was detected, the administration of GM-CSF to AIDS patients with MAC bacteremia resulted in activation of their blood monocytes, as evidenced by increased superoxide anion production and enhanced mycobactericidal activity. GM-CSF deserves further investigation in the treatment of mycobacterial infections.

Author notes

Presented in part: 35th Interscience Conference on Antimicrobial Agents and Chemotherapy, San Francisco, September 1995; IX International Conference on AIDS, Berlin, July 1993.

Informed written consent, approved by the Santa Clara Valley Medical Center Institutional Review Board, was obtained from all study subjects described herein.

Financial support: Immunex Research and Development Corporation, Seattle; partial salary support (C.A.K.) by funds provided by the State of California's Universitywide AIDS Research Program (R90-CC86SD) through the California Collaborative Treatment Group (CCTG).