Fig. 2

APRIL and BAFF CSF levels specifically discriminate CNSL from other brain lesions. Receiver operating characteristic (ROC) curve of 116 patients with focal brain lesions demonstrates a CSF level of APRIL > 6.59 ng/ml with specificity of 93.7% and a sensitivity of 62.3% for active CNSL (area under the curve [AUC], 0.866; 95% confidence interval [CI], 0.800–0.932). A CSF level of BAFF > 299 pg/ml exhibits a specificity of 93.7% and a sensitivity of 47.1% for active CNSL (AUC, 0.831; 95% CI, 0.755–0.910). Bivariate elevation of APRIL and BAFF in CSF had a specificity of 96.1% and a sensitivity of 30.2% for CNSL (AUC, 0.643; 95% CI, 0.543–0.743). Elevation of APRIL and/or BAFF in CSF showed a specificity of 96.1% and a sensitivity of 77.3% for diagnosis of active CNSL (AUC, 0.831; 95% CI, 0.753–0.910)