Getting personal perspectives on individualized treatment duration in multidrug-resistant and extensively drug-resistant tuberculosis.

Tuberculosis (TB) differs from most other bacterial infectious diseases by a very long duration of combination antibiotic therapy required to achieve relapse-free cure. Although the standard recommended "short-course" treatment length for TB is 6 months, the World Health Organization recommends a duration of 20 months for the treatment of patients with multidrug-resistant and extensively drug-resistant TB (M/XDR-TB). Apart from the long duration of anti-TB therapy, treatment of M/XDR-TB is very expensive and often associated with adverse drug events. The optimal duration for treatment of TB likely differs between individuals and depends on a variety of variables, such as the extent of the disease, the immune status of the host, and the virulence and the drug resistance of the causative strain of Mycobacterium tuberculosis. Some patients with M/XDR-TB may have to be treated with currently available antituberculosis drug regimens for more than 20 months, whereas much shorter treatment durations may be possible to achieve cure for the majority of patients with M/XDR-TB. Personalization of the duration of treatment for TB, especially for patients with M/XDR-TB, would be highly desired. Until recently there has been little interest in the identification of biosignatures that could eventually lead to individual recommendations for the duration of anti-TB therapy. This pulmonary perspective reviews the knowledge on clinical and radiological scores, host- and pathogen disease-related profiles, molecules, and signatures that are currently explored as biomarkers to personalize the duration of therapy in TB.