Differential examination of bronchoalveolar lavage cells in tobacco cigarette and marijuana smokers.

Cells derived from bronchoalveolar lavage (BAL) were obtained from 19 healthy non-smokers (NS) and from 43 healthy smokers of tobacco and/or marijuana. Thirteen subjects smoked tobacco cigarettes only (TS) (mean +/- SE: 17.4 +/- 5.5 pack-years). Thirty subjects smoked marijuana; of these, 14 smoked marijuana only (MS) (149.1 +/- 102.7 joint-years) and 16 smoked marijuana and tobacco (MTS) (43.3 +/- 7.2 joint-years and 18.4 +/- 3.2 pack-years). Cell counts were expressed as total number recovered and as number of cells per milliliter of BAL fluid returned. Cell differentials were performed on Giemsa-stained cytopreps. Total cell number was significantly increased in the MTS, TS, and MS compared with that in the NS (p less than 0.01). Heavy tobacco smoking (greater than 10 pack-years) was associated with higher total cell numbers in BAL than was light tobacco smoking (less than 10 pack-years). The MTS had a higher total BAL cell yield per milliliter than did the TS or the MS (p less than 0.004). Marijuana smoking had a significant effect on cell yield independent of the presence or absence of concomitant tobacco smoking (p less than 0.05). Macrophages were the predominant cells in the BAL of TS, MS, and MTS, as well as in the BAL of NS (greater than or equal to 90%). The number of neutrophils (as total recovered or per milliliter of BAL fluid) was significantly higher in the BAL fluid of all MTS and TS than in that of NS (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)