Association study of ghrelin receptor gene polymorphisms in rheumatoid arthritis

Objective Ghrelin is a newly characterised growth hormone (GH) releasing peptide widely distributed that may play an important role in the regulation of metabolic balance in inflammatory diseases such as rheumatoid arthritis (RA) by decreasing the pro-inflammatory Th I responses. In this study we investigated the possible contribution of several polymorphisms in the functional Ghrelin receptor to RA susceptibility. Methods A screening of 3 single nucleotide polymorphisms (SNPs) was performed in a total 4950 RA patients and 990 healthy controls of Spanish Caucasian origin. Genotyping of all 3 SNPs was performed by real-time polymerase chain reaction technology, using the TaqMan 5'-allele discrimination assay. Results We observed no statistically significant deviation between RA patients and controls for the GHSR SNPs analysed. In addition, we performed a haplotype analysis that did not reveal an association with RA susceptibility. The stratification analysis for the presence of shared epitope (SE), rheumatoid factor (RE) or antibodies anti cyclic citrullinated peptide (anti-CCP) did not detect significant association of the GHSR polymorphisms with RA. Conclusion These findings suggest that the GHSR gene polymorphisms do not appear to play a major role in RA genetic predisposition in our population.