IHC was more commonly positive in samples coming from patients with secondary syphilis (PR = 1.441) or second-tertiary syphilis (PR = 1.286), with anti-HIV non-reagent serology (PR = 1.444) or in immunosuppression by HIV with CD4 less than 200 cells/mm3 and VL > 1.000 copies/mL (PR = 1.133). This evidence concerns the gene MLC1 and syphilis.