Advances in the diagnosis of tuberculosis

Abstract

Tuberculosis ranges among the leading causes of morbidity and mortality worldwide. A diagnostic approach to a patient with possible tuberculosis includes a detailed medical history and clinical examination as well as radiological, microbiological, immunological, molecular-biological and histological investigations, where available. Recently, important advances have been achieved in these fields that have led to substantial improvements in the accuracy and the timing of the diagnosis of tuberculosis. Novel methods allow for a better identification of latently infected individuals who are at risk of developing active tuberculosis, they also offer the possibility for a rapid diagnosis of active tuberculosis in patients with negative sputum smears for acid-fast bacilli and enable prompt identification of drug-resistant strains of Mycobacterium tuberculosis directly from respiratory specimen with a high accuracy. In addition, promising methods that will further optimize the diagnosis of tuberculosis are under development. In the future, therapeutic interventions based on the results of novel diagnostic procedures can be made earlier leading to improvements in patient care.

Gene Xpert MTB/RIF Assay: A New Hope for Extrapulmonary Tuberculosis

“…sarcoidosis or NTM infections except for the demonstration of stained tubercle bacilli [6]. Culture test has variable sensitivities of 3-80% in various clinical EPTB samples and it takes 4-8 weeks to get those results and also requires trained technicians [7]. The Mantoux test is widely employed world-wide but the false-positive results are observed due to the previous bacillus Calmette-Guérin (BCG) immunization or exposure to atypical mycobacteria and false-negative results also occur in aged individuals or immuno-suppressed individuals [7].…”

The risk of tuberculosis in transplant candidates and recipients: a TBNET consensus statement

“…Preference is given to sensitivity at the cost of specificity if the expected risk is particularly high, such as in the case of immunodeficiency of an individual [39], but whether this trade-off is as efficient as postulated has been called into question, at least in HIV-associated immunodeficiency [40]. More recently, bloodbased IGRAs have been developed and evaluated for the risk estimation of TB in clinical routine [41]. As with TST, IGRAs rely on specific stimulation of effector T-cells that are activated to produce cytokines within hours after stimulation, and IFN-c is most commonly used as readout for specific activation of T-cells [42].…”

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].…”