<prompt> Test not used for diagnosis of syphilisVDRLTPIReagin TestFrei Test  <response>: D i.e. Frie - test - Most specific test is TPI FTA -ABSQ Non treponemal test becomes non reactive after tt; the Treponemal test often remain reactive therefore not helpful in determining the infection status of person with past syphilis Q. Response to treatment in early syphilis is seen by sequential VDRL or RPR titerQ as they become negative after treatment. CSFVDRL is highly specific but insensitive test; may be nonreactive in symptomatic progressive neuro syphilis. Its sensitivity is highest in meningovascular syphilis paresis. 