Th1/Th2 cytokines and chemokine CXCL13 levels in peripheral blood and cerebrospinal fluid of patients with neurosyphilis and their clinical significance

Abstract

Objective To investigate the Th1/Th2 cytokines and chemokine CXCL13 levels in peripheral blood and cerebrospinal fluid (CSF) of patients with neurosyphilis and their clinical significance. Methods Forty seven HIV negative patients with neurosyphilis, 36 syphilis patients without neurological involvement (syphilis group) and 23 patients without infectious intracranial diseases (control group) admitted in Hangzhou Third Hospital during July 2011 to December 2014 were enrolled in the study. CSF pressure, protein contents, white blood cell counts and IgG index were detected in patients with neurosyphilis. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of Th1 cytokines (IL-2, IL-12 and IFN-γ), Th2 cytokines (IL-6, IL-10) and CXCL13 in serum and CSF in three groups. Th1/Th2 cytokines, CXCL13 levels and CSF routine were also examined in neurosyphilis patients after treatment for 3 and 12 months. ANOVA, Kruskal-Wallis test and Spearman correlation were used for data analysis. Results The levels of IL-6 and IL-10 in serum and CSF from neurosyphilis patients were higher than those in syphilis group and control group(χIL-62=15.43, 15.39 and 14.44, 20.01, χIL-102=16.46, 23.86 and 15.11, 24.44; P<0.05 or <0.01), while the levels of IL-2, IL-12 and IFN-γ in the serum and CSF were lower than those in syphilis group and control group(χIL-22=14.55, 17.14 and 16.14, 17.97; χIL-122=13.65, 20.50 and 18.48, 21.04; χIFN-γ2=16.95, 17.53 and 16.00, 15.21; P<0.05 or <0.01). CXCL13 contents in CSF of neurosyphilis patients were significantly higher than those in other two groups (χ2=52.51 and 53.76, P<0.01), and were positively correlated with leucocyte counts, protein concentrations, IgG index, IL-6 and IL-10 (r=0.325, 0.544, 0.750, 0.333 and 0.382, P<0.05 or <0.01) , but were negatively correlated with IL-12 levels in neurosyphilis patients (r=-0.303, P<0.05). In neurosyphilis patients, CXCL13 and IL-6 levels were reduced after treatment for 12 months (χ2=102.00 and 22.17, P<0.05 and <0.01), while the levels of IL-2 and IL-12 were increased (χ2=18.28 and 24.10, P<0.05 and <0.01). Conclusion Chemokine CXCL13 and Th1/Th2 cytokines are involved in the immune response in neurosyphilis patients, which may be used for the diagnosis and evaluation of therapeutic efficacy in patients with neurosyphilis. Key words: Syphilis; Neurosyphilis; Cerebrospinal fluid; Cytokine; CXCL13