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ISRN Immunology
Volume 2012 (2012), Article ID 237823, 6 pages
http://dx.doi.org/10.5402/2012/237823
Research Article

Analysis of LAM and 38 kDa Antibody Levels for Diagnosis of TB in a Case-Control Study in West Africa

Vaccinology Theme, Medical Research Council Unit, Atlantic Road, Fajara, P.O. Box 273, Banjul, Gambia

Received 10 October 2012; Accepted 28 October 2012

Academic Editors: C. M. Artlett, E. K. Kapsogeorgou, D. Lilic, and I. Mezzaroma

Copyright © 2012 Marie P. Gomez et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

CD4+ T cells are required for protection against tuberculosis (TB) disease progression, but interest in the role of antibodies in early protection, as biomarkers for disease status, and use in diagnostic tests has recently increased. In this study we analyzed plasma antibody levels in TB cases before and after treatment in both HIV-positive and -negative individuals and compared them with tuberculin skin test (TST+) (latently infected) household contacts (HHC). We also analyzed HHC that subsequently progressed to active disease within 2 years in order to see if antibodies play a role in protection against disease progression. We used a commercially available kit to 38 kDa antigen and lipoarabinomannan (LAM) and found that immunoglobulin (Ig) G levels were 4-fold higher in subjects with disease compared to latently infected controls ( ) and were 2-fold higher than pretreatment levels following successful TB treatment ( compared to both pretreated cases and latently infected controls). HIV infection resulted in low antibody levels regardless of disease status or treatment outcome. Furthermore, levels in disease progressors (incident cases) were similar to nonprogressors and were not elevated until just prior to disease progression confirming previous reports that IgG antibodies, at least in the periphery, do not confer protection against TB disease progression.