Value of CXCL13 in diagnosing asymptomatic neurosyphilis in HIV-infected patients

Diagnosing asymptomatic neurosyphilis (ANS) in HIV-infected patients is difficult. A recent report suggested that CXCL13 is a promising diagnostic marker for neurosyphilis in HIV-positive patients. However, whether CXCL13 can be a diagnostic marker for ANS in HIV-infected patients remains unknown. The purpose of our study was to determine the role of CXCL13 in diagnosing ANS in HIV-infected patients. This study comprised two study and three control groups. Two study groups included 12 HIV-infected patients with ANS and 25 patients with syphilis and HIV co-infection (without ANS). Three control groups included 9 patients with ANS without HIV infection, 25 HIV-infected patients without syphilis and 10 healthy volunteers. Concentrations of CSF CXCL13 were measured before and after neurosyphilis therapy. Our results showed that CSF CXCL13 concentrations were significantly increased in all of the HIV-infected patients with ANS, the 25 HIV patients with syphilis and the 9 ANS patients without HIV, but not in the patients of the other two control groups. CSF CXCL13 concentrations declined in the two study groups of patients following neurosyphilis therapy. Therefore, CSF CXCL13 concentrations could improve the diagnosis of ANS in HIV-infected patients.