CD79A and pelvic inflammatory disease: A combination of IgA, IgG, TREC and KREC demonstrated the best AUC 0.77 (95% CI = 0.71–0.82) for “Antibody PID” diagnosis but neither TREC or KREC nor combination of two yielded good diagnostic ability (AUC 0.54, 95% CI = 0.47–0.61), Table 3.