Abstract: Objective: To assess the clinical significance of antinuclear antibody spectrum (ANAs) in the diagnosis of syphilis. Methods: Serum ANAs were detected among 220 patients with positive treponema palladium particle assay (TPPA) and 200 healthy persons with negative TPPA. Results: Among the patients with positive TPPA SSA was positive in 24 patients (10.9%); The positive rates of Ro-52, DsDNA, PCNA, Po and SSB were 16.8%, 4.0%, 7.2%, 3.2% and 7.7%, respectively. All the antibodies of ANAs were significantly higher in the patients with positive TPPA than in the healthy controls (P<0.01). There was no significant difference (P>0.05) in the positivity of ANAs among the patients with positive TRUST and among the patients with negative TRUST. The positive rates of SSA, Ro-52 and SSB were higher in females than in males. The positive rates among those younger than 45 years were relatively low, and increased with age among those older than 45 years. Conclusion: Syphilis infection may increase the risk of autoimmune diseases. ANAs detection may be useful to evaluate the risk of autoimmune disease among the patients with syphilis infection, although there is no diagnostic significance.

Key words: Syphilis antibody, antinuclear antibody spectrum, treponema pallidium particle assay, toluidine red unheated serum test