Acquisition of the rheumatoid arthritis HLA shared epitope through microchimerism.

摘要: Objective HLA–DRB1 alleles associated with risk of rheumatoid arthritis (RA) encode similar HLA–DRB1 sequences, called the shared epitope (SE). The most common SE sequences are QKRAA and QRRAA. Nevertheless, a substantial number RA patients lack SE. Bidirectional fetal–maternal trafficking results in long-term persistence fetal cells mother maternal her offspring, process known as microchimerism. This study was undertaken to discover whether who can acquire it through microchimerism. Methods We studied total 86 female subjects were genotypically negative for SE, comprising 52 34 healthy controls. We developed specific real-time quantitative polymerase chain reaction assays SE-encoded QRRAA, used them test DNA extracted from peripheral blood mononuclear cells. Results Microchimerism found significantly more often than controls (odds ratio 4.1 [95% confidence interval 1.6–10.0], P = 0.003). Concentrations microchimerism also higher among (P 0.002). In separate analyses type, prevalence versus 17% 3% (9 1 34; 0.03) QRRAA 40% 18% (21 6 0.04), respectively. Microchimerism concentrations 0.03). Conclusion These indicate that persistent cell exchange, suggesting SE-encoding could be factor RA.