Microsatellite polymorphism in intron 2 of human Toll-like receptor 2 gene is associated with susceptibility to acute pancreatitis in Japan

This study evaluated the association of the polymorphisms in the Toll-like receptor (TLR)2 and TLR4 genes with acute pancreatitis (AP) in Japan. The numbers of guanine-thymine [(GT)_n] repeats in intron 2 of the TLR2 gene were counted in 202 unrelated patients with AP (80 with severe and 122 with mild disease) and in 286 healthy controls, using polymerase chain reaction and Genescan analysis. The alleles were divided into three subclasses: (GT)₁₆ or less as the S allele; between (GT)₁₇ and (GT)₂₂ as the M allele; and (GT)₂₃ or more as the L allele. Asp299Gly and Thr399Ile polymorphisms in the TLR4 gene were examined by polymerase chain reaction-restriction fragment length polymorphism analysis. Patients with AP had more S alleles (p < 0.001; odds ratio = 2.37; 95% confidence interval = 1.78-3.17) and fewer M alleles (p < 0.001; odds ratio = 0.40; 95% confidence interval = 0.31-0.52) than did healthy controls. Genotypes SS and SL were more common, whereas MM and ML were less common in patients with AP. In subgroup analyses, the genotypes including S alleles were more common in patients with severe AP than in controls. No Asp299Gly and Thr399Ile polymorphisms were detected. In conclusion, microsatellite polymorphism in intron 2 of the TLR2 gene was associated with susceptibility to AP and its severity in Japan.