title: Evaluation of the diagnostic value of measuring IgG, IgM, and IgA antibodies to mycobacterial A60 antigen in active tuberculosis.
abstract: The purpose of the present study was to evaluate the clinical usefulness of detection of serum immunoglobulin A (IgA), IgG, and IgM antibodies raised against the mycobacterial A60 antigen for the diagnosis and discrimination of active tuberculosis (TB) from other pulmonary diseases. Three commercially available ELISA kits (IgA, IgG, and IgM) (ANDA Biologicals, Strasbourg, France) were evaluated simultaneously in 246 serum samples from 3 groups of patients: group I, 171 patients with active TB (128 pulmonary TB and 43 extrapulmonary TB); group II, 73 patients with pulmonary non-TB diseases; and group III, 2 leprosies patients. The sensitivities of tests ranged from 31.3% (IgA) to 94% (IgG) in pulmonary TB patients and from 21% (IgA) to 84% (IgG) in extrapulmonary TB patients. The specificities of assays varied from 92% (IgG) to 96% (IgA) in the pulmonary non-TB group. Combination of IgG with IgA and/or IgM does not improve its sensitivity. Clinical use of the A60-based serodiagnostic IgG assay is of great value for the rapid diagnosis and discrimination between active TB and pulmonary non-TB diseases. Moreover, this test could be used to increase diagnostic accuracy, especially for smear-negative TB cases, which are difficult to diagnose.
authors: Microbiology and Immunology Laboratory, UR02SP13, CHU Farhat Hached, Sousse, Tunisia.
authors: Walid
authors: W
authors: Ben-selma
authors: Hedi
authors: H
authors: Harizi
authors: Manel
authors: M
authors: Marzouk
authors: Imen
authors: I
authors: Ben Kahla
authors: Foued
authors: F
authors: Ben Lazreg
authors: Asma
authors: A
authors: Ferjeni
authors: Jalel
authors: J
authors: Boukadida
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007070:Immunoglobulin A / Q000097:blood*; D007074:Immunoglobulin G / Q000097:blood*; D007075:Immunoglobulin M / Q000097:blood*; D009169:Mycobacterium tuberculosis / Q000276:immunology; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000276:immunology / Q000382:microbiology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M; C055539:mycobacterial A60 antigen