The Usefulness of Toluidine Red Unheated Serum Test in the Diagnosis of HIV-Negative Neurosyphilis

In Brief We retrospectively analyzed the Venereal Disease Research Laboratory test, Treponema pallidum particle agglutination test, and toluidine red unheated serum test (TRUST) in 41 cases of HIV-negative neurosyphilis and 34 non-neurologic syphilitic patient and found that serum-TRUST titers could be the indication of lumbar puncture in syphilitic patients and a reactive cerebrospinal fluid-TRUST is considered diagnostic to neurosyphilis. In a study of clients in a teaching hospital in Guangzhou, China, we found that the TRUST (toluidine red unheated serum test) could be a useful alternative test for diagnosis of neurosyphilis.