Glucocorticoid receptor polymorphisms in rheumatoid arthritis: results from a single centre

Until now, glucocorticoids (GCs) with their anti-inflammatory and immune suppressive effects are one of the most effective agents in therapy of several autoimmune disorders including rheumatoid arthritis (RA). Glucocorticoid receptor (GR) polymorphisms may result in variable sensitivity to glucocorticoids playing an important role in the development and control of symptoms in RA. We aimed to test whether the functional polymorphisms of the GR encoding gene (NR3C1) are associated with susceptibility to RA and with various clinical signs and symptoms.

146 patients were enrolled at the National Institute of Reumatology. Clinical diagnosis was based on the criteria of the American College of Rheumatism (ACR) 2010. Complex clinical, routine laboratory and immunlaboratory evaluations were performed. For genotyping of the GR polymorphisms N363S (rs6195), BclI (rs41423247) and 9β (rs6198) peripheral blood DNA was used, extracted with commercially available reagents. Genotyping was performed with routine molecular biological methods. Genetic data were compared to those obtained in a healthy control group (n=160) using Chi square or Fisher tests. Associations between GR genotypes and clinical and immunological parameters were determined with ANOVA.

The main finding of the present study is the lower frequency of the BclI in RA patients. Furthermore, regarding the laboratory and immunoserological parameters, the level of anti-DNA antibody was significantly higher in homozygous BclI carriers compared to heterozygous carriers, irrespective of the anti-TNF-alpha therapy.

Our results reveal that although GR polymorphisms are not key players in development or clinical course of RA, they might affect glucocorticoid action and, together with other endogenous and exogenous factors, interfere with the pathomechanism of RA. Our results reveal some possible factors (including BclI polymorphism), and therefore contribute to elucidate the implication of the combination of GR functional variants.