The aim of our study was to determine if CXCL13, CXCL10 and CXCL8 can be used to facilitate the diagnosis of ocular syphilis by examining the concentrations of these biomarkers in the serum, aqueous humour (AH) and CSF of patients with ocular syphilis and correlating these results with the clinical presentation, HIV status and routine serological and CSF tests, and to assess the association between ocular syphilis and neurosyphilis. This evidence concerns the gene CXCL13 and neurosyphilis.