THU0012 Clonal analysis of vh and vl mrna in single b and plasma cells from rheumatoid arthritis synovium and peripheral blood

Abstract

Background Genetic polymorphisms, such as the polymorphisms of vitamin D receptor (VDR) and oestrogen receptor (ER) genes play an important role in bone metabolism and the pathogenesis of osteoporosis. Little is known about the role of VDR and ER gene polymorphisms in rheumatoid arthritis (RA), although hormonal factors are highly involved in the evolution of autoimmune disorders. Objectives We assessed VDR BsmI, ER XbaI and ER PvuII polymorphisms in 50 RA patients as well as 50 healthy subjects. Methods Gene polymorphism was assessed in peripheral blood mononuclear cells taken from RA patients and healthy controls. After the PCR amplification of DNA isolated from these cells using specific primer pairs, DNA was digested with BsmI, PvuII and XbaI restriction enzymes. B versus b, X versus x and P versus p alleles, as well as homozygote and heterozygote genotypes were determined by agarose gel electrophoresis. Genotypes were then correlated with the bone density (assessed by DEXA), serum osteocalcin and urinary pyridinolin crosslink concentrations. Disease activity of RA was assessed by ESR and CRP. Results There is difference between VDR and ER polymorphisms in RA patients versus controls. A significantly higher percentage of RA patients carry the VDR Bb heterozygote genotype. XbaI and PvuII ER genotypes are also different in RA patients versus controls. There is a correlation between the VDR and ER genotypes, as well as bone density, biochemical markers and laboratory markers of RA activity. Conclusion It is likely, that VDR and ER polymorphisms are involved in bone metabolism as well as inflammatory events underlying RA.