title: Enzyme-linked immunosorbent assay (ELISA) of antibodies to purified protein derivative (PPD) in the diagnosis of active tuberculosis: evaluation of its potential and limitation in a high prevalence area.
abstract: Sera from patients with active tuberculosis were assayed for IgG antibodies to purified protein derivative (PPD) by an enzyme-linked immunosorbent assay (ELISA) technique. Eighty seven of the 112 patients (78%) with sputum culture-positive, and 57 of 78 patients (73%) with sputum culture-negative, pulmonary tuberculosis had positive serology. Seventeen of 19 patients (89%) with renal tuberculosis (demonstrable lesion on intravenous pyelography) had antibody to PPD, whereas only 3 of 9 patients (33%) with urinary tuberculosis (positive urine culture only, without abnormality on intravenous pyelography) and 8 of 21 patients (38%) with tuberculous cervical lymphadenitis had positive serology. Seropositivity rate in paediatric patients was also low, only 2 out of 8 patients gave positive serology. Thus, the diagnostic value of this test is limited as a positive result is obtained only when the disease is relatively long-standing or extensive.
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005069:Evaluation Studies as Topic; D006723:Hong Kong; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007223:Infant; D008199:Lymphadenitis / Q000175:diagnosis; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D013183:Sputum / Q000382:microbiology; D014373:Tuberculin / Q000276:immunology*; D014376:Tuberculosis / Q000175:diagnosis* / Q000453:epidemiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis*; D014398:Tuberculosis, Renal / Q000175:diagnosis; D014401:Tuberculosis, Urogenital / Q000175:diagnosis
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D014373:Tuberculin