We investigated 30 patients with idiopathic pulmonary fibrosis (IPF) and 103 healthy volunteers for the cytokines polymorphisms of the IL-1α, IL-1β, IL-1R, IL-1RA, IL-2, IL-4, IL-6, IL-10, IL-12, tumor necrosis factor-α, interferon-γ, transforming growth factor-β, IL-1β, IL-2, IL-4, and IL-4RA genes. The strongest correlation of a genotype with the disease was found for gene polymorphisms at the promotor region of IL-4, where the CT genotypes at the positions (-590) and (-33) were more frequent in the IPF group (P < 0.0001, P corr < 0.0022; vs P < 0.0001, P corr < 0.0022).
Our results support the idea of the pathogenic role of cytokine gene polymorphisms in the etiology and pathogenesis of IPF, with emphasize on the IL-4 promotor gene polymorphisms.