LYMPHOCYTIC SUBPOPULATION PROFILES IN BRONCHOALVEOLAR LAVAGE FLUID AND PERIPHERAL-BLOOD FROM TOBACCO AND MARIJUANA SMOKERS

The effect of heavy, habitual marijuana use compared with tobacco smok ing on the composition of bronchoalveolar and peripheral blood lymphoc ytic phenotypes was examined. Bronchoalveolar lavage (BAL) and periphe ral blood (PB) samples were taken from 14 nonsmokers (NS), 14 tobacco smokers (TS), 19 heavy, habitual marijuana smokers (MS), and 9 marijua na and tobacco smokers (MTS). In BAL fluid, marijuana use was associat ed with significantly higher alveolar macrophage concentrations, where as tobacco smoking was associated with significantly higher alveolar m acrophage, as well as higher bronchoalveolar lymphocyte and neutrophil concentrations. The bronchoalveolar T-lymphocytic phenotypic profiles of marijuana users differed from those of tobacco smokers. Tobacco, n ot marijuana, was found to have a significant effect toward lower perc entages of bronchoalveolar CD4 cells, toward higher concentrations of bronchoalveolar CD8 cells, and toward lower bronchoalveolar CD4:CD8 ra tios. Marijuana use had a significant effect toward lower percentages of bronchoalveolar CD8 cells. In peripheral blood, marijuana, but not tobacco, use was associated with significantly higher percentages of C D4 cells, lower percentages of CD8 cells, and higher CD4:CD8 ratios. T hese findings suggest that tobacco and marijuana have effects on bronc hoalveolar and peripheral blood immunoregulatory T-lymphocytic subpopu lations that differ in type or magnitude.