FIGURE 1.

Serum IgG4 titre discriminates between IgG4‐related disease (IgG4‐RD) and primary sclerosing cholangitis (PSC) with high sensitivity but low specificity. (A) Patients with IgG4‐RD had elevated serum IgG4 titres (Mann Whitney U test, p < .0001). Median ± interquartile range showing all points. While HC serum IgG4 was not measured, the normal range (.04–0.86 g/L) is indicated in green. (B) ROC curve for IgG4 titre classifying PSC vs IgG4‐RD. ROC curves show AUC ± 95% confidence intervals. N = 80 (PSC) and 38 (IgG4‐RD). ****Mann Whitney U test, p < .0001