ROC analysis
In the CIS-RRMS group, ROC analysis identified both CXCL13 (AUC = 0.959) and IL-8 (AUC = 0.939) in cerebrospinal fluid (CSF) as significant predictors for the conversion from clinically isolated syndrome (CIS) to relapsing-remitting multiple sclerosis (RRMS).
The optimal cut-off value for IL-8 in CSF was determined to be 45.6 pg/ml, as calculated by the Youden’s J statistic, which maximizes the sum of sensitivity (0.9) and specificity (0.836). For CXCL13 in CSF, the optimal cut-off value was 0.210 pg/ml, also determined by Youden’s J statistic, with sensitivity of 0.95 and specificity of 0.873. This test showed higher sensitivity. Alternatively, if a higher cut-off value (1.795) were selected, both sensitivity and specificity would be more balanced, both approximately at 0.9, with SE = 0.900 and SP = 0.909. The data are summarized in the Figure 4 and depicted in the