CD40LG and rheumatoid arthritis: Levels of IgM against IGKC2−19 HNE were significantly 1.93- (p < 0.0001) and 2.12-fold (p < 0.0001) greater in RA patients than in OA patients and HCs, respectively (Fig. 3l, left panel), and AUC values were 0.86 (with 83.3% sensitivity and 66.7% specificity) for detecting RA and 0.58 (with 68.6% sensitivity and 51.7% specificity) for detecting OA (Table 2).