Effects of Genetic Polymorphisms of Programmed Cell Death-1 in Susceptibility with Rheumatoid Arthritis in Najaf Population

Abstract

Background: The prevalence of Rheumatoid Arthritis (RA) has been raised in Iraq. The medical costs of such increased prevalence are high. Global studies have revealed polymorphisms of PD1 (Program Death 1) gene to be associated with Rheumatoid Arthritis (RA). This polymorphism can cause changes in various metabolic variables. Methods: The current study consists of 100 RA patients and 100 healthy control individuals. Variable parameters data included Anti-Cyclic cytrulinated peptide expression (ACCP), Rheumatoid factor (RF), C-Reactive Protein (CRP) in serum and Erythrocytes sedimentation rate (ESR) leveles. Genotyping of PD1gene polymorphism is carried out by RFLP-PCR. Various statistical analyses were applied to analyze the data. Results: The estimation of immunological and biochemical data pointed out significant differences in Gender, RF, ACCP, CRP, ESR and age in RA when compared with those of the control group. The genotyping results were found to be consistent with Hardy-Weinberg equilibrium. The analysis of the genotype distribution under various inheritance models highlighted significant differences in SNP of PD1 gene polymorphism among RA patients when compared with the control group under the dominant homozygote, heterozygote and recessive homozygote. The genotype and allele frequencies of the PD1 SNP rs11568821; genotype GA was significantly increased in RA compared with controls (45% and 24%, respectively) (P=0.0020),(OR =2.5909),(95% CI 1.4-4.7) . Subjects who carried A allele were significantly more likely to develop RA three folds AA(OR=3.3529, 95% CI=1.1691-9.6160, P=0.0244). Clinical characteristics were observed to change significantly with respect to the genotype distribution of the investigated SNP. Conclusion: PD1 gene polymorphisms (rs11568821) is implicated in the pathogenesis of Rheumatoid arthritis in Najaf population.