Effect of variation in ITGAE on risk of sarcoidosis, CD103 expression, and chest radiography

The integrin alpha(E)beta(7) is believed to play a key role in retention of lymphocytes in mucosal tissues of gut, urogenital tract and lung. Five common single nucleotide polymorphisms spanning ITGAE, the gene encoding the alpha(E) (CD103) unit, were genotyped in 556 sarcoidosis patients and 465 controls. The -1088 A/G polymorphism was associated with sarcoidosis (P=0.004). An increased risk of disease was found for homozygous carriers of the A allele vs. carriers of the G allele (P=0.001, odds ratio=1.63 [1.22-2.17]). Analysis of lymphocytes from bronchoalveolar lavage and in vitro functional tests showed higher percentages of CD103+CD4+ T cells for the sarcoidosis risk genotype. Radiographic staging at disease outcome revealed prevalence of -1088 AA genotype in patients with fibrosis (P=0.01). A higher proportion of CD103+CD4+ T cells and ITGAE -1088 AA genotype might be associated with fibrosis formation in pulmonary sarcoidosis.