Analysis of SEVA TB ES-31 antigen specific immunoglobulins IgM, IgA and IgG in sera of sputum and culture positive pulmonary tuberculosis

Abstract

Tuberculosis remains major health problem in India and developing countries~ Immunodiagnosis has important role in screening, diagnosis and management of tuberculosis. SEVA TB ES-31 antigen has shown potential in detecting tuberculous IgG antibody in earlier studies from our laboratory. In the present study we have analysed SEVA TB ES-31 antigen specific immunoglobulins IgM, IgA and IgG in clinically and bacteriologically confirmed pulmonary tuberculosis cases to determine the usefulness of specific immunoglobulin class in the diagnosis of patients attending the hospital.Of the 30 cases of pulmonary tuberculosis 25 (83.3%) were positive for IgG, 19 (63.3%) for IgM and 16 (53.3%) for IgA. On combining IgG and IgM positivity, sensitivity was increased to 93.3%. While combining IgG and IgA positivity, sensitivity increased to 90%. However specificity was decreased to 66.6% and 70% for both of these combinations respectively. It could be envisaged from this study that IgG antibody detection against ES 31 antigen showed acceptable sensitivity (83.3%) and specificity (86