DECREASED EXHALED NITRIC-OXIDE IN SUBJECTS WITH HIV-INFECTION

Background - Nitric oxide (NO) may be an important component of the ho st defence against infections. Endogenously produced NO is present in exhaled air and may be representative of respiratory tract production of NO. Since subjects infected with HIV are prone to develop respirato ry infections, it was postulated that exhaled NO might be reduced in s uch individuals. Methods - The exhaled concentration of NO (n1/1) and minute ventilation (1/min) were measured and exhaled NO release (nl/ m in/m(2)) calculated in 36 subjects infected with HIV (20 non-smokers, 16 smokers) and 31 non-smoking subjects with no active medical conditi ons. Results - Exhaled NO from HIV positive individuals was less than from control subjects of similar age, height, and weight. Cigarette sm oking did not account for the decreased exhaled NO in HIV positive ind ividuals as both smoking and non-smoking HIV positive subjects had dec reased exhaled NO compared with control subjects. Conclusion - Exhaled NO is decreased in subjects infected with the HIV. Since NO functions in host defence against bacterial, viral, and fungal infections, redu ced exhaled NO may indicate a mechanism of impaired host defence in HI V infection.