Expression of CXCL2 in the Serum and Cerebrospinal Fluid of Patients with HIV and Syphilis or Neurosyphilis

The potential mechanisms for blood–brain barrier damage and the diagnosis of neurosyphilis in HIV patients co-infected with syphilis (HIV-S) are unclear. The aim of the study was to determine the expression of CXCL2 in the serum and cerebrospinal fluid (CSF) of HIV-S patients. A total of 34 HIV patients and 7 controls were enrolled in a HIV clinical cohort for diagnosis of neurosyphilis in Taiwan. Serum and CSF concentrations of CXCL2 were determined by ELISA. Neurosyphilis was defined as a CSF white blood cell count of ≧20 cells/μl or a reactive CSF Venereal Disease Research Laboratory (VDRL). Demographics and medical histories were collected. All the patients with HIV-S were males. Most (80 %) had sex with men (MSM) and serum rapid plasma reagin (RPR) titers of ≧1:32. The medium age was 37 (range 21–68) years. The medium CD4 T cell counts at the time of the diagnosis of syphilis were 299 (range 92–434) cells/μl. Eight patients (24 %) had neurosyphilis based on a reactive CSF VDRL test (n = 5) or increased CSF white blood cell counts of ≧20 cells/μl (n = 3). The concentrations of CSF CXCL2 were significantly higher in patients with HIV and neurosyphilis as compared to HIV with syphilis, HIV, and controls (p = 0.012). There were no significant differences in serum concentrations between the four groups. There was a correlation between CSF CXCL2 concentrations with neurosyphilis (p = 0.017), CSF white blood cell count (p = 0.001), and CSF protein levels (p = 0.005). The CSF level of CXCL2 can be used to distinguish those with or without neurosyphilis in HIV infected patients.