Abstract:
Background: Previous studies have revealed an association between interleukin 17A
(IL-17A) polymorphisms and the prevalence of rheumatoid arthritis (RA) in Japanese
and Caucasian patients. It was hypothesized that IL-17A polymorphisms might also
affect RA susceptibility in the Pakistani population.
Methods: In this study, two polymorphisms including IL-17A SNPs rs8193036 and
rs2275913 were examined in a case – control study of Pakistani population through
Polymerase Chain Reaction - Restriction Fragment Length Polymorphism (PCR -
RFLP). Methylation Specific PCR was followed by bisulfite conversion of genomic
DNA to evaluate the methylation status of IL-17A promoter region
Results: The study showed association value of 8.760 and the p value 0.0125 for the
genotype data for SNP rs2275913. While no association was found between
rs8193036 and RA (p = 0.5223). IL-17A rs2275913 (A>G) was found associated with
decreased risk of RA. Methylation status of IL17A promoter showed statistically
significant association to RA (p = 0.0001).
Conclusion: The present study demonstrated that the IL17A SNP rs2275913 (A>G)
significantly decreases the risk of RA. While no association was found between
IL17A SNP rs8193036 (C>T) and risk of RA. Methylation status of the IL17A
promoter region is significantly associated with the disease. However, these results
were obtained from only a moderate-sized sample population. Replication of these
findings in larger populations from diverse ethnicity are required to confirm these
findings
