Fluorescent antibody tests for syphilis using cerebrospinal fluid: clinical correlation in 150 cases.

Abstract

The charts of 150 patients were reviewed to determine the correlation between clinical findings and results of serologic tests for syphilis in serum and cerebrospinal fluid specimens of the patients. Patients were divided into three groups. (1) Those diagnosed as syphilitic. Serum Venereal Disease Research Laboratory (VDRL) and fluorescent treponemal antibody-absorbed (FTA-ABS) tests of the 49 patients of this group were reactive in 78% and 98%, respectively. The cerebrospinal fluid VDRL, FTA, FTA-ABS tests were reactive in 12%, 61%, and 22%. The clinical diagnosis of neurosyphilis had been made for 18 of these patients, with 22%, 89%, and 22% having reactive VDRL, FTA, and FTA-ABS results, respectively. (2) Those with undiagnosed syphilis and reactive serum FTA-ABS results. Cerebrospinal fluid VDRL, FTA, and FTA-ABS tests of the 34 patients in this group were reactive for 0%, 62%, and 9%, respectively. (3) Those with no clinical evidence of syphilis and nonreactive serum FTA-ABS tests. Cerebrospinal fluids of three of the 67 patients in this group had reactive FTA tests and an additional three had weakly reactive FTA results. The results obtained in this study have demonstrated the value of FTA and FTA-ABS tests of the cerebrospinal fluid for the diagnosis of neurosyphilis in the large number of cases in which the TPI test offers extremely low sensitivity. Until more information is available, it appears desirable to recommend the FTA procedure as a screening test, and use the VDRL and FTA-ABS tests simultaneously to examine all cerebrospinal fluids reactive with the FTA test. Tests of the serum and pertinent clinical findings should remain a prerequisite for interpretation of laboratory findings in the cerebrospinal fluid.