Alveolar macrophage activation in HIV infection.
Alveolar macrophage function is critical to the pulmonary immune response to infection. It is not known whether alveolar macrophages from HIV-infected individuals function normally in vivo. We have measured neopterin concentration, a marker of macrophage activation, in induced sputum, serum and saliva samples from control and HIV-infected subjects, with and without intercurrent lower respiratory tract infection (LRTI). Induced sputum (IS) neopterin concentration was increased in non-AIDS HIV positive (NAHIV) subjects (mean 3.5 nmol/l) compared to controls (mean 0.6 nmol/l) (P = 0.01) and it was further increased in patients with AIDS (mean = 27.7 nmol/l) (P = 0.002). When only those without LRTI were considered, the difference between the NAHIV and AIDS groups remained significant (P = 0.007). Those with LRTI had a significantly higher IS neopterin concentration (mean 53.2 nmol/l) than those without LRTI (mean 3.9 nmol/l) (P = 0.001). Contamination of the sample with saliva was not significant as there was no correlation between IS and saliva neopterin concentration (R = 0.1) and the concentration of neopterin was not related to the proportion of alveolar macrophages in IS samples (R = 0.2). Similarly there was no correlation between IS and serum neopterin concentration (R = 0.1). These results indicate that alveolar macrophages from NAHIV and AIDS subjects were in an activated state in vivo and that LRTI caused further stimulation (reflected in higher IS neopterin concentrations).
Division of Infectious Diseases, St. George's Hospital Medical School, London, U.K.
M R
MR
Evans
M H
MH
Wansbrough-Jones
D000328:Adult; D001708:Biopterins / Q000031:analogs & derivatives / Q000032:analysis; D005260:Female; D015658:HIV Infections / Q000276:immunology*; D006801:Humans; D008262:Macrophage Activation; D016676:Macrophages, Alveolar / Q000502:physiology*; D008297:Male; D019798:Neopterin; D013183:Sputum / Q000737:chemistry
D001708:Biopterins; D019798:Neopterin