https://imcjms.com Ibrahim Medical College Journal of Medical Science https://imcjms.com/registration/journal_full_text/155 Thu, 15 Dec 2016 17:04:43 +0000 Background and objective: This study focused on the analysis and comparison of humoral immune response to Mycobacterium tuberculosis (MTB) cell wall fraction (CWF) and lipoarabinomannan (LAM) antigens.   Tuberculosis (TB) caused by Mycobacterium tuberculosis(MTB) is one of the leading causes of death in the world. The estimated incidence of TB and its annual mortality in Bangladesh is 225 and 45 per 100,000 populations [1]. Early diagnosis and treatment of TB patients is crucial for the control of TB [2].In the recent years, understanding of humoral immune response to MTB and the detection of MTB antigen specific antibodies has been an important tool in the diagnosis of TB cases [3]. This is particularly important for pediatric and extra pulmonary tuberculosis and in those unable to produce sputum. Thus, exploring the antibody response to defined MTB antigens might be of great benefit for early diagnosis and control of TB as well as to understand the immunity to tuberculous infection.   The study was conducted in the Department of Microbiology, Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorders (BIRDEM), Dhaka. Informed consent was obtained from each of the participant. Antigens: Purified CWF and LAM antigens of MTB were used. The antigens were obtained from the Department of Microbiology, Immunology and Pathology, Colorado State University, 1682 Campus Delivery, Fort Collins, CO 80523, USA. Detection of antibody by ELISA: IgM and IgG antibodies to CWF and LAM antigens were determined by enzyme linked immunosorbent assay (ELISA). ELISA was performed as described by Voller et al [8]. Briefly, the 96 well EIA plate was coated with respective antigen (CWF or LAM) at a concentration of 5µg/ml. The optimum working concentration of each antigen was predetermined by checkerboard method using antigen concentration of 2.5 µg/ml, 5 µg/ml and 10 µg/ml. Initially, checkerboard method was also used to optimize the working serum dilution (1:400 for IgM and 1:1600 for IgG). IgM or IgG anti-human-HRP conjugate was used at a dilution of 1:5000 (MP Biomedicals, USA). Absorbance optical density (OD) was read at 450nm in Human ELISA reader. 1.   World Health Organization. Global tuberculosis report 2016. Geneva: World health organization 2016; 214 p. 3.   Wu X, Yang Y, Zhang J, Li B, Lian Y, Zhang C, Dong M. Comparison of antibody responses to seventeen antigens from Mycobacterium tuberculosis. Clin Chim Acta 2010; 411(19-20): 1520–1528. doi: 10.1016/j.cca.2010.06. 014. 2026 Ibrahim Medical College. All rights reserved.