Omentin-1 Genetic Variation (rs2274907) and Serum Level Serve as Prospective Markers for Rheumatoid Arthritis in Pakistan

Abstract Background Rheumatoid arthritis (RA) is second leading arthritis worldwide which is characterized by severe joint inflammation. There are several environmental and genetic factors that can influence its pathogenesis. Omentin-1, produced by omental adipose tissues has anti-inflammatory property. The study is designed to evaluate the association between Omentin-1 serum levels and single nucleotide polymorphisms (rs2274907 and rs2274908) with susceptibility to Rheumatoid arthritis (RA). Methods and Results The study involved 792 participants, 396 RA patients and 396 healthy controls. It was found from ELISA that serum Omentin-1 levels were significantly different between cases and controls (p < 0.0001). After DNA extraction Amplification Refractory Mutation System and Allele-specific Polymerase Chain Reaction were performed. Genotype association analysis showed significant distribution in genotype frequency of rs2274907 (χ2 = 72.6, p < 0.001) in RA patients. According to genetic models, co-dominant AT (4.02 times) and dominant (3.95 times) genotypes for rs2274907 could increase the risk of RA. Allele association analysis suggested that the patients with the T allele conferred higher risk (1.73 times, p < 0.0001) for development of RA. There was no association found for rs2274908 variations. Multi-locus analysis between the targeted polymorphisms showed that TG haplotype was involved in progression of RA (OR = 1.79, p < 0.0001) while AG haplotype have a protective effect towards the disease (OR = 0.44, p < 0.0001). These haplotypes can be inherited with 90% linkage disequilibrium. Conclusions It is evaluated from the results that the genetic variant of Omentin-1 polymorphism (A/T rs2274907) may act as possible molecular and genetic targets for early diagnosis of RA and help to develop better therapeutic protocols.