Fig 1: Receiver operating characteristic (ROC) curves for the salivary immunoglobulin gamma-3 chain C region (IGHG3) and lactoferrin (LTF) for the diagnosis of systemic lupus erythematosus (SLE). The area under the curve (AUC), sensitivity, and specificity of sIGHG3 were 0.75, 78%, and 64.6%, respectively, with a cut-off value of 2.26 pg/mL for the diagnosis of SLE compared to healthy controls (HCs). The AUC, sensitivity, and specificity of salivary LTF were 0.84, 91.9%, and 60.6%, respectively, with a cut-off value of 4.36 pg/mL for the diagnosis of SLE.