Background: Patients with chronic immune thrombocytopenia (cITP) have troubles with their immune system. Nevertheless, the exact role of the immune checkpoint pathway in the development of cITP remains unknown. We aimed to investigate the impact of programmed death-1 (PD-1, PDCD1) SNPs (rs1386349 rs2227982) on the susceptibility clinical features of cITP.

Methods: Thirty cITP pediatric patients thirty sex age-matched healthy children were included as a control group. PDCD1 polymorphisms using a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) system.

Results: As regards SNP (rs2227982), 24 (80.0%) of the cases group had genotype CC, 6 (20.0%) had genotype CT, and no one had genotype TT. There, 27 (90.0%) of the control group had genotype CC, 3 (10.0%) had genotype CT, and no one had genotype TT. There 54 (90.0%) of the cases group had Allele C, and 6 (10.0%) had Allele T. There were 57 (95.0%) in the control group had Allele C, 3 (5.0%) had Allele T, according to SNP (rs1386349). There, 25 (83.3%) of the cases group had genotype CC, 4 (13.3%) had genotype CT, 1 (3.3%) had genotype TT. There, 26 (86.7%) of the control group had genotype CC, 4 (13.3%) had genotype CT, no one had genotype TT, 54 (90.0%) of the cases group had Allele C, 6 (10.0%) had Allele T, 56 (93.3%) of the cases in the control group had Allele C, and 4 (6.7%) had Allele T.

Conclusion: The Pd1 gene polymorphisms (rs1386349 rs2227982) do not affect susceptibility or clinical features among cITP patients.