Serological evaluation for tuberculosis by antigen 60 IgG ELISA test.
BACKGROUND
Tuberculosis remains a significant global health problem, especially among developing countries. It unfortunately results in high morbidity and mortality rates. This disease is also prevalent to a large extent in Taiwan. The traditional tuberculous tests, including the acid-fast smear and culture, have a limited activity in regard to extrapulmonary or smear-negative tuberculosis. A new testing is necessary to improve diagnosis of this disease.


METHODS
An enzyme-linked immunosorbent assay (ELISA) test for detection of serum IgG antibodies, based on Antigen 60, was applied to 146 subjects including 68 non-tuberculous cases and 78 tuberculous cases. A titer of less than 200 serounits was considered negative, and one of 200 or more serounits was thought positive.


RESULTS
In the healthy group, which included 5 newborns, 5 children and 20 healthy adults, 6.1% (2/30) showed positive results. Of the 15 hospital attendants, 60% (9/15) also displayed positive results. Nine of 17 cases (52.9%) with non-tuberculous pulmonary diseases had positive results. Among 6 cases with other diseases, the results were all negative. The false positive rate in non-tuberculous group was 29.4% (20/68). In 10 cases with inactive pulmonary tuberculosis, 30% (3/10) showed positive results. In 50 with active pulmonary tuberculosis, 88% (44/50) generated positive results. Effectual results were obtained in 66.7% (8/12) of the cases with extrapulmonary tuberculosis. Including 6 cases with mixed pulmonary and extrapulmonary tuberculosis, 83.3% (5/6) proved positive results. The positive rate in active tuberculous group was 83.8% (57/68).


CONCLUSIONS
The ELISA test, for detection of IgG antibody with Antigen 60, is helpful in improving the diagnosis of tuberculosis, especially in extrapulmonary tuberculosis.
Department of Medicine, Veterans General Hospital-Taipei, Taiwan, R.O.C.
F D
FD
Wang
W J
WJ
Su
T N
TN
Jang
C Y
CY
Liu
D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology*; D002648:Child; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood*; D007231:Infant, Newborn; D008875:Middle Aged; D014376:Tuberculosis / Q000175:diagnosis*
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007074:Immunoglobulin G; C055539:mycobacterial A60 antigen