NONSPECIFIC IMMUNITY IN AGED HEALTHY-SUBJECTS AND IN PATIENTS WITH CHRONIC-BRONCHITIS

We investigated the effects of aging on some functional activities (ch emotaxis, phagocytosis, nitroblue tetrazolium reduction and candidacid al activity) of peripheral polymorphonuclear and mononuclear phagocyte s in 96 healthy subjects and 89 patients with chronic bronchitis, aged 40 to 100 years. The subjects were divided according to age into youn ger (40-65 years) and older (66-100 years) individuals. No subject was taking any drug known to affect phagocytic functions. A few abnormali ties in PMN and monocyte functions were observed in aged healthy subje cts, in comparison to the younger ones; in fact, only the chemotactic response to complement-derived chemotactic factors was significantly i mpaired in elderly healthy individuals. On the contrary, multiple alte rations of phagocyte activities, i.e., chemotaxis, phagocytosis, and c andidacidal activity were observed in aged subjects with chronic bronc hitis, compared to healthy adults. However, the results obtained in ol der and younger patients with chronic bronchitis were superimposable. The present data suggest that the decline in functional activities of phagocytes in the aged could depend on the effect of the underlying ch ronic bronchitis on the cellular components of the non-specific host d efense system, rather than a direct effect of the aging process.