Fluorescent treponemal antibody tests on cerebrospinal fluid.

There have been many evaluations of the absorbed fluorescent treponemal antibody (FTA-ABS) test on serum. Its reactivity on cerebrospinal fluid (CSF) is less well documented, although studies have recently been reported by Escobar, Dalton, and Allison (1970), Garner and Backhouse (1971), and Duncan, Jenkins, and Parham (1972). The last workers recommend the testing of undiluted and un- absorbed CSF, as described by Harris, Bossak, Deacon, and Bunch (1960), but they think that the specificity of this method needs further evaluation before it can be adopted as a routine test. In the FTA-ABS test anti-human immunoglobulin con- jugates are used which react mainly with IgG anti- body. O' Neill and Nicol (1972) have suggested that the presence of IgM anti-treponemal antibody in serum may reflect an untreated or recently treated infection and that this antibody is the first to dis- appear after treatment.