Introduction: The genetic variations of co-stimulatory molecules can affect the extent of T cell activity during T-cell mediated immunity, especially in transplant patients. This study aimed to investigate the association of programmed cell death 1 (PDCD1) and programmed cell death 1 ligand 1 (PDCD1LG1) gene polymorphisms with clinical outcome of kidney transplantation.
Materials and methods: A total of 122 patients with a kidney transplant were included in this retrospective study. Patients were classified into two groups of biopsy-proven acute allograft rejection (AAR) and stable graft function (SGF) during the 5-year follow-up period. Four single nucleotide polymorphisms in PDCD1 and PDCD1LG1 were determined in the groups of patients as well as in 208 healthy control individuals.
Results: The frequencies of PD-1.3 (+7146 G>A), PD-1.9 (+7625 C>T), PD-L1 (8923 A>C), and PD-L1 (+6777 C>G) genotypes and alleles were not significantly different between the AAR and SGF groups. In comparison with healthy controls, PD-1.9 (+7625 C>T) genotype and T allele were significantly more frequent in all of the patients and in those with SGF. Overall, 27 of 122 kidney allograft recipients experienced delayed graft function, and a higher frequency of PD-1.9 (+7625 C>T) genotype and T allele was observed in this group versus those without delayed graft function. Similarly, a significant high frequency of this genotype was found among the AAR subgroup of patients with delayed graft function.
Conclusions: Our results indicate that potentially functional genetic variation in PDCD1 can influence the outcome of kidney transplantation.