HIV-1 infection does not impair human alveolar macrophage phagocytic function unless combined with cigarette smoking.
OBJECTIVE
Macrophages are an important reservoir for the HIV and contribute to innate lung defense by their ability to phagocytose, digest, and process invading pathogens. We hypothesized that HIV-1 infection may lead to a defect in the phagocytic activity of alveolar macrophages.


METHODS
In order to test this hypothesis, the phagocytic activity of alveolar macrophages from asymptomatic HIV-1 seropositive subjects was compared to healthy seronegative control subjects. Macrophages from one cohort were fed with Escherichia coli and from another cohort with opsonized sheep RBCs (SRBCs), and the phagocytic index was determined at different time intervals.


METHODS
A tertiary-care, urban, university-based referral center.


METHODS
Asymptomatic HIV-1 seropositive subjects and healthy seropositive control subjects recruited from local community.


RESULTS
No differences were found in the phagocytic activity between alveolar macrophages from the first cohort of eight seropositive and nine seronegative subjects. Although not statistically significant, there was a trend toward a lower phagocytic activity of HIV-positive smokers compared to HIV-positive nonsmokers. Opsonized phagocytic capacity (using opsonized SRBCs) was further analyzed in a second set of five HIV-positive subjects and five healthy control subjects. Whereas HIV status did not affect opsonized SRBC uptake, a history of smoking was associated with a statistically significant depression in phagocytic index.


CONCLUSIONS
Although there is no significant impairment of phagocytic capacity in HIV-positive subjects compared to HIV-negative control subjects, cigarette smoking produces a significant depression in phagocytic activity that is amplified in HIV-positive smokers.
Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210, USA.
Andreas
A
Elssner
Jo E
JE
Carter
Thomas M
TM
Yunger
Mark D
MD
Wewers
D000328:Adult; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D004912:Erythrocytes; D004926:Escherichia coli; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D006679:HIV Seropositivity / Q000276:immunology; D015497:HIV-1; D006801:Humans; D016676:Macrophages, Alveolar / Q000276:immunology*; D008297:Male; D009895:Opsonin Proteins; D010587:Phagocytosis; D012907:Smoking / Q000276:immunology*
D009895:Opsonin Proteins