Combination of the neutrophil to lymphocyte ratio and serum toluidine red unheated serum test titer as a predictor of neurosyphilis in HIV-negative patients

The present study explored the associations of the neutrophil to lymphocyte ratio (NLR) and the serum toluidine red unheated serum test (TRUST) titer with neurosyphilis (NS). The present retrospective study examined 87 NS patients and 80 Non-NS patients from an HIV-negative cohort and 1:1 age- and gender-matched healthy controls. The results demonstrated that the NLR was increased in both NS and Non-NS groups compared with that in the healthy controls (P<0.001 and P=0.01, respectively). The NLR and serum TRUST titer in the NS group were significantly higher than those in the Non-NS group (P=0.004 and P<0.001, respectively). The NLR was positively correlated with the serum TRUST titer (r=0.298, P<0.001). Age, elevated NLR and serum TRUST titer were distinctly associated with NS by binomial logistic regression analysis [odds ratio (OR)=1.10, P<0.001; OR=1.36, P=0.028; OR=3.07, P<0.001; respectively]. The cut-off values for the NLR and serum TRUST titer were 1.97 and 1:8, respectively. A significantly higher sensitivity of 90.8% was obtained for screening out NS with a combination of the NLR and serum TRUST titer compared with each test alone. Age, elevated NLR and serum TRUST titer were associated with NS. The combination of NLR and serum TRUST titer is a potential predictor for NS, and the reduced NLR and serum TRUST titer at the 6-month follow up suggested that the NLR and serum TRUST titer were biomarkers for monitoring the disease course.