The relationship of serum IL-17 and IL-21 levels and TRUST titer in syphilis patients with positive serological test

Abstract

Objective: To explore the immune mechanism of syphilitic sero-fixation by measuring the expression levels of serum IL-17 and IL-21 in syphilis patients with positive serological test. Methods: Subjects included syphilitic sero-fixation, syphilis with Toluidine red unheated serum test (TRUST) negative, early syphilis, and normal healthy controls, 30 subjects per groups. Serum concentrations of IL-17 and IL-21 were measured by ELISA, while TRUST titers were measured with TRUST kit. The differences in serum IL-17 and IL-21 levels were compared among four groups. Pearson correlation analysis was used to analyze the correlation between TRUST titers and IL-17 and IL-21 levels. Results: The serum levels of IL-17 [(25.43±4.58) pg/mL]and IL-21[(36.14±6.54) pg/mL] in early syphilis group were significantly higher than that in the other three groups (P0.05). The serum levels of IL-17 and IL-21 were correlated positively with TRUST titers in the early syphilis patients (r=0.75, 0.62, respectively, both P0.05). Conclusions: Both IL-17 and IL-21 are involved in the syphilis immune process in early syphilis. The formation of syphilitic sero-fixation could be associated with decreased serum levels of IL-17 and IL-21, but not TRUST titers.

Keywords

• syphilitic sero-fixation
• il-17
• il-21
• trust