CD40LG and rheumatoid arthritis: Quantitative analysis results showed that the level of RF_IgA in peripheral blood of RA patients was 42.25 (24.56, 81.64) IU/mL; the level of RF_IgG was 24.21 (10.06, 67.33) U/mL, and the level of RF_IgM was 46.32 (7.55, 145.86) IU/mL.