COTININE LEVELS IN SERUM AND BRONCHOALVEOLAR LAVAGE FLUID

Cotinine is a major metabolite of nicotine. This study was planned to investigate the relationship between bronchoalveolar lavage (BAL) fluid cotinine levels and serum cotinine levels in smokers and nonsmokers with various pulmo- nary diseases and to investigate whether these levels are affected by passive smok- ing. Serum and BAL fluid cotinine levels were measured in 27 patients. BAL cotinine levels were measured using a sensitive ELISA kit produced to measure cotinine in saliva. Plates were read by ∝Quant (BioTek, USA) micro plate reader. All patient serum cotinine levels were detectable except for one nonsmoker patient. How- ever, BAL fluid cotinine levels were measurable in only 6 patients (two of them were nonsmokers). A significant positive correlation was seen between serum and BAL fluid cotinine levels (r=0.726; p=0.000). Serum cotinine levels were signifi- cantly higher in present smokers than non-smokers (21.0±16.01; 5.35±7.65; p=0.004). However, there were no significant differences in BAL fluid cotinine levels be- tween smokers and nonsmokers. Passive smoking can increase nicotine metabo- lites in serum and other body fluids, including BAL fluid. Since BAL fluid and serum cotinine levels were well correlated, there is no need to use invasive proce- dures, such as bronchoscopy and expensive, time consuming BAL fluid analyses. Serum cotinine levels can give a rough idea of smoking status. BAL fluid cotinine meaurements should be done for only scientific reasons.