Improvement in neutrophil and monocyte function during highly active antiretroviral treatment of HIV-1-infected patients

Objective: To investigate the effect of highly active antiretroviral treatm ent (HAART) on neutrophil and monocyte function in patients with moderately advanced HIV-1 infection. Design: Eighteen HIV-1-infected patients with CD4 T cell counts below 350/m u l, no concomitant active infection, and no previous use of protease inhib itors were treated with indinavir or ritonavir and two reverse-transcriptas e inhibitors and were followed up for 9 months. Ten age- and sex-matched he althy subjects were included as controls. Methods: The functional activity of neutrophils and monocytes was measured by assessing chemotaxis towards a bacterial peptide, killing activity again st Candida albicans, and oxidative burst as measured by chemiluminescence p roduction. Results: Neutrophils and monocytes from the treatment group exhibited a sig nificantly diminished baseline chemotactic and fungicidal activity compared with healthy controls (P < 0.001). After starting HAART, there was a signi ficant improvement in chemotaxis and fungicidal activity of phagocytic cell s (P < 0.001). Values of chemotaxis reached normal ranges in 13 out of 18 p atients (72%) for neutrophils and eight out of 18 (44%) for monocytes, wher eas phagocyte killing was rarely restored to normal values (3/18 cases for monocytes and 0/18 for neutrophils). The administration of HAART was also a ssociated with significantly increased phagocyte chemiluminescence producti on in response to phorbol-12-myristate 13-acetate or opsonized C. albicans (P < 0.01). Conclusion: The functional improvement of two critical components of innate antimicrobial immunity, such as neutrophils and monocytes, may contribute to the improved cell-mediated immune responses against opportunistic infect ions in HAART-treated patients. (C) 1999 Lippincott Williams & Wilkins.