CD40LG and syphilis: VDRL sensitivity stratified by stage: primary 58%, secondary 100%, tertiary 100%, and latent 88%. TPPA sensitivity stratified by stage: primary 93%, secondary 100%, tertiary 100%, and latent 100%. Pathozyme IgM: sensitivity stratified by stage: primary 96%, secondary 91%, tertiary 62%, and latent 79%. For primary syphilis, the VDRL test should not be recommended as first-line screening test because of its lack of sensitivity.