The relationships of renal function markers with disease activities and neurosyphilis in HIV-negative patients with syphilis.

OBJECTIVES

To investigate the associations between renal function markers and disease activities and neurosyphilis in patients with syphilis.

METHODS

A total of 390 HIV-negative syphilis patients were included in the study. Serum blood urea nitrogen (BUN), creatinine (CR), and estimated glomerular filtration rate (eGFR) were used as markers of renal function. Binary logistic regression models and restricted cubic splines were performed to investigate the associations of renal function markers with neurosyphilis.

RESULTS

BUN and CR were positively correlated with serum TRUST titer and cerebrospinal fluid (CSF) protein, whereas eGFR was inversely correlated with serum TRUST titer, CSF-protein and erythrocyte sedimentation rate. Renal function markers were associated with neurosyphilis, and the adjusted odds ratios (95% CIs) for the highest versus lowest tertiles of BUN and CR were 1.81 (1.04-3.13) and 2.27 (1.22-4.22). Multivariable-adjusted restricted cubic spline analyses suggested there were dose-response relationships of BUN and CR with neurosyphilis (P for linearity < 0.05). Furthermore, the addition of BUN or CR to the conventional model improved risk reclassification of neurosyphilis.

CONCLUSIONS

Renal function markers were associated with disease activity of syphilis and the likelihood of neurosyphilis in HIV-negative patients with syphilis. These findings highlight the critical role of renal function monitoring in syphilis management.