Detecting latent tuberculosis in compromised patients

The detection of latent tuberculosis infection (LTBI) in different categories of compromised patients isreviewed with focus on the role of strategies incorporating immunodiagnostic tests and analysis ofepidemiological and clinical risk factors.Recent findingsThe development of active tuberculosis (TB) is increased in compromised patients and is closely related todeterminants for disease reactivation or newly acquired TB infection. A targeted detection of LTBI in thesehigh-risk groups should be performed especially if preventive treatment is planned. The performance ofimmunodiagnostic tests is highly variable among different groups of immunocompromised individuals.Findings of cross-sectional studies indicate a better diagnostic accuracy of interferon-grelease assays overthe tuberculin skin test. The critical issue is that in low-incidence countries, the positive and negativepredictive values of any of immunodiagnostic tests were very poor. A targeted testing process involvinganalysis of TB risk factors increases the predictive positive values of immunodiagnostic tests and mayimprove LTBI detection.SummaryThe LTBI detection in immunocompromised patients is a challenge. The development of new immunologicalbiomarkers and integrated clinical and epidemiological strategies are needed to identify LTBI incompromised individuals and to plan preventive chemotherapies in those at risk of developing active TB.