Soluble antigen fluorescent antibody test in the serodiagnosis of tuberculous meningitis

Diagnosis of tuberculous meningitis (TBM) is difficult and frustrating. Modified soluble antigen fluorescent antibody (SAFA) test was applied to 40 CSF and 32 serum samples from 48 patients to assess the efficacy of this test in the rapid diagnosis of TBM. Using this test, false negative results were obtained in 41.6% and 40% of CSF and serum samples. False positive results were obtained in 22.2% and 26.7% of CSF and serum samples respectively. SAFA test was not found to be helpful in the sero-diagnosis of TBM. It is suggested that the best immunodiagnostic test for TBM will be to demonstrate the presence of antigen, antibody and antigen-antibody complex in the CSF for M. tuberculosis.