Background Rheumatoid arthritis (RA) is a disease characterized by chronic inflammation of synovial tissue, and progressive destruction of the joints. In RA patients a high prevalence of serum vitamin D deficiency/insufficiency was described. Vitamin D has a central role in the immune system and also correlates with increased levels of estrogen receptor α.
Objectives The study analyzed the relationships between polymorphisms in the gene for vitamin D receptor (VDR) and the development and/or progression of the disease.
Methods A total of 156 patients were enrolled with a diagnosis of RA (median age 55.6 years; 78% of them women; control group of 50 subjects). Development of the disease was scored by positive antibodies against cyclic citrullinated peptide (anti-CCP), rheumatoid factor (RF), CRP. Disease progression was assessed by the modified Sharp-van der Heijdeovou method Total Sharp Score (TSS). Polymorphisms were detected by PCR and subsequent restriction analysis (rs4516035 EcoRV; rs7975232: ApaI; rs731236: TaqI).
Results The results show the relation of polymorphism VDR rs4516035 to seropositivity for anti-CCP in the distribution of genotypes (P=0.03), with a higher prevalence of the TT genotype when compared to the CC + CT variants (p=0.007, OR =3.2). The relationship was found also in the frequency of alleles (p=0.04). Further, a borderline relationship of this polymorphism to RF IgA levels (P=0.06) was detected. A relationship of polymorphism VDR rs731236 with the disease progression evaluated by TSS (p=0.02) was demonstrated, with the highest TSS in the patients carrying the GG variant.
Conclusions The results show that the GG variant of VDR rs731236 polymorphism was associated with a worse prognosis of RA. Moreover, the VDR rs4516035 polymorphism was related to the seropositivity for anti-CCP, with a significant prevalence of TT genotype in positive RA patients.
Disclosure of Interest None declared