Invited Speaker

New Paradigm in Tuberculosis Serodiagnosis: Computational Analysis to Classify Profiles of anti-M. tb. Antibodies Detected by Multiplex Microbead Array
Imran H. Khan, Resmi Ravindran, Irum Nawaz, Kumail Rizvi, Azra Khanum, Sabira Tehseen, Phil Felgner, Greg Ireton and Paul A. Luciw
USA


Multiplex approach to serodiagnosis enables simultaneous detection of antibodies against hundreds of antigens in one reaction vessel. Multiplex microbead (Luminex®) system conserves sample, is cost effective, accurate, user-friendly and amenable to automation/high-throughput. Detection of multiple antibodies (profiles) is particularly important in serodiagnosis of TB because different TB patients do not make antibodies to the same antigen(s). Luminex microbeads were coated with 30 M.tb. antigens to develop a multiplex microbead immunoassay. Plasma samples were obtained from 300 TB patients and healthy controls from a TB endemic country, Pakistan. The multiplex assay allowed simultaneous detection of multiple antibodies of diagnostic value in TB patient plasma. Computational methods using algorithms for multivariate analysis were employed to efficiently analyze large volumes of data generated from hundreds of TB patients using dozens of antigens. This approach enabled classification of antibody profiles of diagnostic value that closely correlated with sputum smear (acid fast bacteria - AFB) microscopy-based TB diagnostic method practiced commonly in TB endemic countries. These findings suggest that plasma antibody (anti-M. tb.) profiles are useful in TB diagnosis. An automated and high-throughput version of this approach could efficiently test thousands of samples from TB patients (and house-hold contacts) per day thus, allowing timely treatment of TB and helping curtail the spread of disease.