Background: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive dyspnea and worsening lung function due to remodeling of the lung, including epithelial mesenchymal transition. ADAM33 is a disintegrin and metalloprotease domain-containing protein, which may be related to lung fibrosis by exerting angiogenesis and remodeling of the lung. Thus, we evaluated the association of single-nucleotide polymorphisms (SNPs) of ADAM33 with the risk of IPF.
Methods: A total of 237 patients with IPF and 183 healthy subjects participated in the present study. Nine polymorphisms were selected. Genotyping was performed by single-base extension. Polymorphisms and haplotypes were analyzed for associations with the risk of IPF using multiple logistic regression models controlling for age, gender, and smoking status as covariates.
Results: All SNPs were in Hardy-Weinberg equilibrium. The minor allele frequency (MAF) of rs628977G>A in intron 21 was significantly lower in subjects with surgical IPF than in normal controls in the recessive model [33.2 vs. 38.0 %, p = 0.02, OR = 0.40 (0.19-0.84)]. When the subjects with clinical IPF were included, the difference in MAF persisted with a p value of 0.03 [OR = 0.50 (0.27-0.94)].
Conclusions: ADAM33 rs628977G>A was marginally associated with a decreased risk of IPF in a recessive model.