Evaluation of enzyme-linked immunosorbent assay (ELISA) in serodiagnosis of pulmonary tuberculosis

Abstract

A total of 45 patients with pulmonary tuberculosis and 45 healthy individuals were subjected to chest examination, radiography and ELISA tests for IgA and IgG antibodies. Sputum smear and culture were performed for all tuberculous patients. Evaluated against clinical and radiological diagnosis, ELISA's specificity exceeded 90% in detecting specific IgA and IgG antibodies. The parallel application of ELISA and microscopic examination of sputum yielded 80% sensitivity compared with clinical and radiological examination and 100% sensitivity compared with culture. ELISA alone can be used in ruling out pulmonary tuberculosis but not in diagnosing the disease. However, coupled with microscopic examination, it can be used instead of culture to provide positive diagnosis within 24 hours.