Serodiagnosis of Tuberculosis Using an ELISA with Antigen 5 and a Hemagglutination Assay with Glycolipid Antigens: Results in Patients with Newly Diagnosed Pulmonary Tuberculosis Ranging in Extent of Disease from Minimal to Extensive

Abstract

Hemagglutination tests with three glycolipid antigens, A1, B1, and C, and ELISA with antigen 5 were done on serum from Chinese patients with pulmonary tuberculosis and from normal subjects in Hong Kong. Tests with all four antigens were of similar efficiency, giving positive results in 30 to 52% of 88 smear-positive patients, in 16 to 22% of 37 smear-negative, culture-positive patients, in 5 to 13% of 76 culture-negative patients with radiologically active disease, in 5 to 11% of 217 culture-negative patients with inactive disease, and in 1 to 4% of 140 normal subjects. if tests were combined so that an overall positive was scored when all tests were positive, there was worse discrimination between patients and normal subjects; however, as suggested by the poor correlation between the results with pairs of the tests, better discrimination was obtained if an overall positive was scored when any of the tests was positive. A positive result in any of the four tests was found in 22% of all cases, including 58% of smear-positive patients, 32% of smear-negative, culture-positive patients, and 0.7% of normal subjects.