MUC5B Polymorphism in Patients with Idiopathic Pulmonary Fibrosis—Does It Really Matter?

Idiopathic pulmonary fibrosis (IPF) is a rare disorder concerning elderly people, predominantly men, active or former smokers, with a progressive nature and leading to premature mortality. The cause of the disease is unknown. However, there are some risk factors, among which genetic predisposition plays a role. The aim of our single-centered observational study was to assess the correlation between single nucleotide polymorphism (SNP) of the <i>MUC5B</i> gene (rs35705950) and the disease course, antifibrotic treatment effect, and survival in patients with IPF. A total of 93 patients entered the study, of whom 88 were treated with either nintedanib or pirfenidone. The GG genotype was found in 28 (30.1%) subjects, while the GT or TT genotypes were found in the remaining 65 (63.4%) and 6 (6.5%) patients, respectively. The T allele minor allele frequency (MAF) accounted for 38.2% of the whole group. Patients with different genotypes did not differ significantly regarding age, sex, pulmonary function tests' results, response to the antifibrotic treatment, or survival. However, we found a survival advantage in female patients and patients with higher pre-treatment TL,co. Treatment with antifibrotics significantly decreased the magnitude of FVC and TL,co decline compared to the time before treatment initiation, regardless of <i>MUC5B</i> status. In conclusion, we found high prevalence of T allele of <i>MUC5B</i> gene in patients with IPF; however, it showed no influence on disease trajectory, survival, or antifibrotic treatment effect in the presented cohort.