title: Development of a proof of concept immunochromatographic lateral flow assay for point of care diagnosis of Mycobacterium tuberculosis.
abstract: BACKGROUND
  Despite major public health initiatives and the existence of efficacious treatment regimes, tuberculosis (TB) remains a threat, particularly in resource-limited settings. A significant part of the problem is the difficulty of rapidly identifying infected individuals, and as a result, there has been renewed interest in developing better diagnostics for infection or disease caused by Mycobacterium tuberculosis. Many of the existing tools, however, have limitations such as poor sensitivity or specificity, or the need for well-equipped laboratories to function effectively. Serodiagnostic approaches in particular have long drawn attention, due to their potential utility in large field studies, particularly in resource-poor settings. Unfortunately none of the serodiagnostic approaches have so far proven useful under field conditions.
  
  
  RESULTS
  We screened a large panel of antigens with serodiagnostic potential by ELISA and selected a subpanel that was strongly and broadly recognised by TB patients, but not by controls. These antigens were then formulated into a simple immuno-chromatographic lateral flow assay format, suitable for field use, and tested against panels of plasma and blood samples from individuals with different clinical status (confirmed TB patients, household contacts, and apparently healthy community controls), recruited from Ethiopia (a highly TB-endemic country) and Turkey (a TB meso-endemic country). While specificity was good (97-100% in non TB-endemic controls), the sensitivity was not as high as expected (46-54% in pulmonary TB, 25-29% in extra-pulmonary TB).
  
  
  CONCLUSIONS
  Though below the level of sensitivity the consortium had set for commercial development, the assay specifically identified M. tuberculosis-infected individuals, and provides a valuable proof of concept.
authors.affiliation: Armauer Hansen Research Institute, P.O. Box: 1005, Jimma Road, Addis Ababa, Ethiopia. wassieliya@gmail.com
authors.forename: Liya
authors.initials: L
authors.lastname: Wassie
authors.forename: Markos
authors.initials: M
authors.lastname: Abebe
authors.forename: Abraham
authors.initials: A
authors.lastname: Aseffa
authors.forename: Kidist
authors.initials: K
authors.lastname: Bobosha
authors.forename: Martha
authors.initials: M
authors.lastname: Zewdie
authors.forename: Menberwork
authors.initials: M
authors.lastname: Chanyalew
authors.forename: Lawrence K
authors.initials: LK
authors.lastname: Yamuah
authors.forename: Arantxa
authors.initials: A
authors.lastname: Cortés
authors.forename: Jose R
authors.initials: JR
authors.lastname: González
authors.forename: Jose M
authors.initials: JM
authors.lastname: Delgado
authors.forename: Ismail
authors.initials: I
authors.lastname: Ceyhan
authors.forename: Ida
authors.initials: I
authors.lastname: Rosenkrands
authors.forename: Karin
authors.initials: K
authors.lastname: Weldingh
authors.forename: Peter
authors.initials: P
authors.lastname: Andersen
authors.forename: Timothy Mark
authors.initials: TM
authors.lastname: Doherty
mesh_terms: D000942:Antigens, Bacterial / Q000032:analysis; D002846:Chromatography, Affinity / Q000379:methods*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000276:immunology / Q000302:isolation & purification*; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D000942:Antigens, Bacterial