Diagnosing tuberculosis poses a great challenge. Although AFB smear is the most important criteria for the presumptive diagnosis of TB, its major limitation is its low sensitivity. Our aim is to investigate the clinical utility and accuracy of serodiagnosis using ELISA test among AFB smear negative TB patients.
This a validation study/ diagnostic test evaluation. Consecutive patients suspected of TB with AFB smear negative were evaluated. Data abstracted from the medical records included the patient demographics and clinical presentation. The results of the serologic test were compared to the standard diagnosis of TB. Histopathologic examination and clinical response to treatment were used as gold standard.
606 patients were included in the study. With a TB prevalence of 35.7%, the test had a sensitivity of 48%,specificity of 96.8%, LR (+) 16, LR(-) .537, positive predictive value of 89.5%, negative predictive value of 77% and over all accuracy of 79.4%.
This serologic test is a useful armamentarium in the diagnosis of TB due to the likelihood positivity of 16 in this test compared to standard diagnosis.CLINICAL IMPLICATION: This serologic test will be a useful in diagnosing smear negative patients highly suspected of having TB and in cases of extrapulmonary TB where the utility of conventional laboratory tests are limited.
R.A. Santos, None.