Asociación del polimorfismo del Gen PD-1 (PD-1.3G/A) con el desarrollo de hepatitis autoinmune tipo 1 en población mestiza venezolana

Introduction: Autoimmune hepatitis (AIH) is a progressive liver disease showing genetic susceptibility. The inhibitory PD-1 molecule acts as a surface receptor. One of the SNPs, PD-1.3G/A has been associated with susceptibility to autoimmune diseases. Experimental findings suggest that PD-1 may play an important role in the development of autoimmune liver pathologies. Objective: to establish the PD-1 gene polymorphism (PD-1.3 G/A) and its potential association to type 1 AIH in Venezuelan mestizo patients. Methodology: 70 patients with type 1 AIH and 120 healthy individuals were studied, both groups being third generation Venezuelans. The determination of the polymorphisms was done through PCR, using specific oligonucleotide initiators followed by restriction enzyme digestion (PstI). Results: the most frequent allele in both population groups was the wild G allele (92.9% and 95.4%) with very similar frequencies. The most frequent phenotype was the wild homozygote genotype (G/G), both in patients and controls (87.2% and 90.8%, p=0.42) with higher values observed in the second group. The G/A genotype is more often found among patients (11.4% vs 9.2%, p=0.62). The A/A homozygote genotype was only present in one patient and in none of the controls (1.4% vs 0%, p=0.19). None of these differences was significant. Conclusion: no difference was found in the genotype distribution of the PD-1 gene (PD-1.3G/A) observed in patients and healthy individuals, which suggests that in our population the susceptibility for Type 1 AIH is not affected by this gene’s polymorphism.