Tumor Necrosis Factor Alpha and Pulmonary Function in Saskatchewan Grain Handlers

Objective: The objective of this study was to estimate the contribution of lifestyle (cigarettes) and tumor necrosis factor (TNF) alpha polymorphisms at position 308 of the tumor necrosis factor alpha gene promotor (TNF-308*1/*2) to pulmonary function among grain handlers. Methods: Employed male grain handlers (157) provided occupational and respiratory symptom information, pulmonary function measurements, and DNA for genotyping. Results: The genotypes of 101 were TNF-308*1/*1, 47 were *1/*2, and nine were *2/*2. Current smokers whose genotype was *2/*2 or *1/*2 had lower values compared with other combinations of genotype and smoking status. Among *1/*1 homozygotes, current smokers had better percent of predicted forced expiratory volume in 1 second (P = 0.04) mean values than nonsmokers and better percent of predicted forced vital capacity than exsmokers (P = 0.017) or nonsmokers (P = 0.008). Conclusions: These results indicate the complexity of determining which workers will develop acute and chronic adverse pulmonary conditions in response to exposure to grain dust and the toxins in cigarette smoke interacting with their genotype.