Diagnostic value of detection of TRUST and TPPA in CSF on neurosyphilis

Abstract

Objective To assess the specificity and sensitivity of syphilis toluidine red untreated serum test (TRUST) and treponema pallidum particle agglutination (TPPA), and further explore their values in the diagnosis of neurosyphilis and the accuracy in determining the efficacy of treating neurosyphilis. Methods The serum and CSF samples of 255 HIV-negative patients were examined by TRUST and TPPA. Patients diagnosed as having neurosyphilis accepted treatment with large dose of Penicillin G and re-checked the blood and CSF with TRUST and TPPA halfyear later. Results One hundred and three patients were diagnosed as having neurosyphilis. The sensitivity and specificity indexes of TRUST in the CSF were 78.64% and 99.34%; those of TPPA measurement in the CSF 100% and 100%. The positive rate in detecting the neurosyphilis between these 2 measurements were significantly different (P＜0.05). Ninety-two patients were followed up and serum-examined by TRUST and TPPA and 76 were re-checked the CSF by TRUST and TPPA halfyear later; TRUST and TPPA on the CSF turnedto negative results at a ratio of (25%,0), and those on the blood (1.87% and 0), respectively. The TRUST showed that negative ratio in the CSF was significantly higher than that in the blood after half year treatment (P＜0.05). Conclusion Detection on the CSF with TPPA should be accepted to substitute VDRL as the best serological test in the diagnoses of neurosyphilis, and that on CSF with TRUST can be used as an index of evaluating the treatment. Key words: Neurosyphilis; Syphilis toluidine red untreated serum test; Treponema pallidum particle agglutination