Tuberculosis assays: past, present and future

Abstract

Recent developments in the field of TB diagnostics, including the introduction of the Xpert MTB/RIF assay in field testing, raise the hope for faster and more accurate identification of active TB patients. However, there are still many issues that need to be addressed as no point-of-care tests are yet available. Furthermore, no tests are available which are universally applicable to all patients. Improvements in the microbiological and molecular-based approaches are promising and the diagnostic pipeline is encouraging. Host markers associated with active disease may hold promise, especially in situations where sputum diagnostics are problematic, including in children, HIV-infected individuals and in the case of extrapulmonary TB.

IP-10 release assays in the diagnosis of tuberculosis infection: current status and future directions

“…Further evidence has since substantiated this discovery and >40 additional biomarkers have been screened for diagnostic potential. Of all investigated markers, it appears that IP-10 is the most consistently expressed in response to antigen challenge, rendering it the most promising alternative marker to IFN-g [18][19][20][21][22][23][24][25][26][27] and a promising means of improving IGRAs [28][29][30][31][32][33][34].…”

Diagnóstico patológico y molecular de un caso de tuberculosis laríngea primaria en un médico

“…Entre las técnicas de laboratorio disponibles para el diagnóstico de esta enfermedad están el análisis histológico, que detecta hasta 88 % de los casos, la tinción de Ziehl-Neelsen sobre el tejido o el esputo, el cultivo de secreciones pertinentes y la búsqueda de ADN micobacteriano mediante la técnica de reacción en cadena de la polimerasa (PCR), la cual es muy útil en el diagnóstico rápido de esta entidad y de todas las formas de tuberculosis extrapulmonar y pulmonar paucibacilar (24,33,34).…”

Clinical Laboratory Diagnostics for Mycobacterium tuberculosis

“…Therefore, a positive stain from a respiratory specimen is typically thought to correlate with a higher infectivity potential and patients are routinely placed in airborne isolation rooms until their acid-fast smears convert to negative. Immunocompromised individuals often present with lower bacterial loads making detection by smear difficult (Chegou et al, 2011). Up to 30% of persons (commonly children) are unable to produce sputum for a smear requiring the use of more invasive methods (gastric washing, bronchoalveolar lavage, etc).…”