title: Seroreactivity of 31 kDa and 41 kDa mycobacterial secretory proteins isolated from culture filtrate in extra pulmonary tuberculosis.
abstract: Despite rapid advances in molecular genetics for detection of mycobacteria, it is clear that interest in serodiagnosis remains high, especially for those situations in which a specimen may not contain the infecting agent in particular in extrapulmonary tuberculosis. Immune response to excretory-secretory (ES) proteins of Mycobacterium tuberculosis (M.tb) has been of diagnostic interest in tuberculosis. In earlier study from our laboratory, a secretory protein M.tb ES-31 has been shown to have diagnostic potential in pulmonary tuberculosis. Further, another M.tb H37Ra ES protein (ES-41) was isolated and purified by trichloroacetic acid solubilization followed by Fast Performance Liquid Chromatography (FPLC). These two protein fractions viz ES-31 and ES-41 secreted by M.tb H37 Ra bacilli were employed in stick indirect penicillinase ELISA to study seroreactivity in extra pulmonary tuberculosis namely tuberculous lymphadenopathy, tuberculous meningitis, abdominal tuberculosis and bone & joint tuberculosis. While using ES-31 antigen 88% (22/25) of tuberculous lymphadenopathy and 90% (9/10) of tuberculous meningitis cases showed positive reaction for tuberculous IgG antibody, ES-41 showed 80% positivity in both groups. In abdominal and bone & joint tuberculosis cases, ES-41 antigen showed better sensitivity of 81.5% (22/27) and 84.6% (22/26) respectively in IgG antibody detection compared to 70% (19/27) and 69.2% (18/26) shown by ES-31. This study is of interest that different antigen protein fractions of M.tb exhibit differential seroreactivity, as ES-31 protein showed good potential in detecting tuberculous IgG antibodies in tuberculous lymphadenopathy (TBLN) & tuberculous meningitis (TBM), while ES-41 in abdominal and bone & joint tuberculosis cases.
authors.affiliation: Jamnalal Bajaj Tropical Disease Research Centre, Department of Biochemistry, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Wardha.
authors.forename: Swati
authors.initials: S
authors.lastname: Banerjee
authors.forename: Sonika
authors.initials: S
authors.lastname: Gupta
authors.forename: Satish
authors.initials: S
authors.lastname: Kumar
authors.forename: A V
authors.initials: AV
authors.lastname: Shrikhande
authors.forename: M V R
authors.initials: MV
authors.lastname: Reddy
authors.forename: B C
authors.initials: BC
authors.lastname: Harinath
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D000942:Antigens, Bacterial / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D008970:Molecular Weight; D009169:Mycobacterium tuberculosis / Q000276:immunology*; D012698:Serologic Tests; D014376:Tuberculosis / Q000175:diagnosis / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007074:Immunoglobulin G; C072681:Mycobacterium tuberculosis antigens