CXCL8 and neurosyphilis: The combination assay of CSF CXCL13, CXCL10 and CXCL8 (Model 1) had 90.4% sensitivity, 82.9% specificity, and yielded an AUC of 0.949 (95% CI 0.926–0.972) for the diagnosis of neurosyphilis (Table 1), and 77.9% sensitivity, 92.6% specificity, and yielded an AUC of 0.925 (95% CI 0.885–0.964) for the diagnosis of asymptomatic neurosyphilis (Table 2).