PR deficiency leads to increased serum IgG1 and IgG2c autoAb levels in aged female Nba2 mice. (A) Serum anti-chromatin IgM, IgG1 and IgG2c levels in female and male mice at indicated ages were determine by ELISA. Shown are medians (lines) and individual values (symbols). *, p < 0.05, **, p < 0.01 Mann-Whitney test. (B) Cumulative IgM, IgG1 and IgG2c in female and male mice at ages 8 and 10 mo. as calculated by area under curve (AUC, see text). Shown are means (lines) and individual values (symbols). *, p < 0.05, **, p < 0.01 unpaired t test of log-transformed data. (C) Total serum IgM, IgG1 and IgG2c levels at 10 mo. Shown are means (lines) and individual values (symbols). *, p < 0.05, **, p < 0.01 unpaired t test.