4-HYDROXY-1-(3-PYRIDYL)-1-BUTANONE-HEMOGLOBIN ADDUCTS AS BIOMARKERS OF EXPOSURE TO TOBACCO-SMOKE, VALIDATION OF A METHOD TO BE USED IN MULTICENTER STUDIES

Hemoglobin (Hb) adducts of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB), a metabolite of two tobacco-specific nitrosamines [4-(methylnitrosamino )-1-(3-pyridyl)-1-butanone and N'-nitrosonornicotine], were measured a s biomarkers of exposure to tobacco smoke as part of a study on geneti c alterations and susceptibility to lung cancer among nonsmokers. HPB- Hb adducts were measured after collection of RBCs by Ficoll gradient i n six collaborating centers, release of HPB by alkaline hydrolysis fro m Hb, clean-up by solid-phase extraction, and analysis of an electron- capturing derivative by gas chromatography-electron capture mass spect rometry. Prior to analysis of samples from study subjects, the reprodu cibility of this approach was validated in blood from donors. The coef ficient of variation of reproducibility of paired aliquots from five s amples ranged from 7 to 25%; the within-sample reproducibilities of fo ur and eight aliquots were 4 and 16%, respectively. The study subjects consisted of 18 smokers and 52 never-smokers. HPB-Hb adduct levels we re significantly higher (P = 0.02) in smokers (26 +/- 13 fmol HPB/g Hb ) than in never-smokers (20 +/- 8 fmol HPB/g Hb), There was no differe nce between sexes. These results suggest that the level of HPB-Hb addu cts, measured using a method modified to facilitate use in multicenter studies, can be a useful biomarker of exposure to tobacco smoke.