Background: PTPN22 gene, located on the long arm of chromosome 1, encodes PTPN22 protein, known as lymphoid tyrosine phosphatase (Lyp). The function of Lyp is suggested to be negative regulation of T-cell reaction through dephosphorylation of Src family kinases – Lck and Fyn, negative regulatory kinase Csk and other signaling molecules. Several studies suggested that individuals lacking the C allele of the C1858T PTPN22 gene polymorphism may have reduced capacity to downregulate T-cell response. Therefore, they may present changes in immunological reaction and be more susceptible to autoimmunity.
The aim of this study was to examine the association of the rs2476601 (C1858T) PTPN22 gene polymorphism with transplanted kidney function.
Material/Methods: The study enrolled 269 Caucasian renal transplant recipients (166 males, 103 females, mean age 47.63±12.96 years). Genotyping of the rs2476601 (C1858T) PTPN22 gene polymorphism was performed using the PCR-RFLP method.
Results: Comparison of the distribution of genotypes and alleles of the rs2476601 PTPN22 gene polymorphism among patients with delayed graft function (DGF) and without DGF revealed no statistically significant differences (OR=0.69, 95%CI=0.37–1.28, p=0.29) for TT+CT vs. CC genotypes. Similarly, there were no statistically significant differences in regard to the studied polymorphism and acute rejection (OR=0.79, 95%CI=0.41–1.52, p=0.52) or chronic allograft nephropathy (CAN) occurrence (OR=1.22, 95%CI=0.64–2.32, p=0.61).
Conclusions: We found no association between rs2476601 (C1858T) PTPN22 gene polymorphism and transplanted kidney function.

Keywords: acute rejection, CAN, DGF, kidney allogaft, PTPN22