Polymorphisms in the CD14 gene associated with pulmonary function in farmers

Rationale and Objectives: Farmers experience airway obstruction, which may be attributable in part to endotoxin inhalation. CD14 is a receptor for endotoxin. Materials and Methods: Based on our findings of increased circulating CD14 associated with the CD14/ -159 T allele, we hypothesized that carriers of this allele would have decreased lung function among endotoxin-exposed individuals. CD14/-159TT farmers (n = 19) had significantly lower lung function as measured by FEV₁ (p = 0.028) and mean forced expiratory flow during the middle half of the FVC (FEF_25-75) (p = 0.05) compared with farmers with the C allele (n = 78). Also, farmers with the CD14/-1619GG genotype (n =11) were associated with lower lung function (FEV₁, p = 0.008; FEF_25-75, p = 0.009) compared with farmers with the A allele (n = 86). Results: No association between CD14/-550 and lung function was observed (FEV₁, p = 0.32; FEF_25-75, p = 0.11). Increased prevalence of wheezing was reported in farmers homozygous for CD14/-159T (p = 0.013) or CD14/-1619G (p = 0.019) compared with farmers with the CC or AA genotype, respectively. No association was found between TLR4/Asp299Gly and lung function or wheeze. Conclusion: We conclude that the CD14/-159 or CD14/-1619 loci may play a role in modulating lung function and wheeze among agricultural workers.