Association of PTPN22 single nucleotide polymorphisms (-1123G/C, +788G/A and +1858C/T) with inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a class of chronic inflammatory disorders including, Crohn's disease (CD) and ulcerative colitis (UC). The PTPN22 gene is thought to be a T-cell negative regulator, regulates immune cell activation, and an important risk factor for human autoimmunity. This study aimed to investigate the potential association of PTPN22 gene single nucleotide polymorphisms (SNPs) with inflammatory bowel disease in Egyptian patients and their relation to clinical disease characteristics. Three SNPs in the PTPN22 gene (-1123G/C, +788G/A, and +1858C/T) were investigated in 90 IBD patients (19 with CD and 71 with UC) and 81 apparently healthy controls. These 3 polymorphisms were genotyped by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Allele and genotype frequencies were correlated with disease association and with clinical disease characteristics. No statistically significant differences in the genotype and allele frequencies of the PTPN22 gene SNPs (-1123G/C, +788G/A, and +1858C/T) were found between IBD patients and control subjects. In conclusion although the PTPN22 gene is involved in autoimmune diseases, it does not appear to be associated with IBD predisposition or its clinical characteristics in Egyptians.