Fig. 1.

Relationship between anti‐measles immunoglobulin (Ig)G and anti‐citrate synthase (CS) IgG antibody titers in the undivided serum bank of systemic autoimmune diseases (SAD) serum samples (n _SAD = 374 = n _RA 73 + n _SLE 92 + n _SSc 157 + n _other 52). Qualitative (positive, negative) anti‐measles IgG results were compared to quantitative anti‐CS IgG results (expressed in arbitrary units, based on our in‐house standard), using Mann–Whitney U analysis. Significantly higher anti‐CS IgG titers were detected in the anti‐measles IgG‐seropositive compared to ‐seronegative SAD patients. Boxes show interquartile ranges (IQR); whiskers indicate lowest and highest values; horizontal lines represent medians.