Immune and inflammatory function in cigarette smokers.

Tobacco smoking is associated with increased prevalence of various diseases, both in the respiratory tract and in distal organs. The possibility that tobacco smoke induced changes in immune and inflammatory processes may play a part in the aetiology and pathogenesis of many of these diseases was first recognised in the mid 1960s. The ensuing decade witnessed a steadily increasing research effort centred on toxico- logical aspects of chronic inhalation of tobacco smoke in relation to immune and inflammatory cell function in experimental animals. This work (reviewed by Holt and Keast') defined a discrete pat- tern of change in animals during the course of tobacco smoke exposure, with the following salient features: (1) systemically, biphasic fluctuations were observed in primary T cell dependent humoral and cellular immune responses, initial enhancement dur- ing the first few months of exposure eventually giving way to suppression in chronically exposed animals;