To the Editors:
We read with interest the recent European Respiratory Journal article by Singla et al. [1], which described the treatment outcome of 29 (pre-)extensively drug-resistant (XDR) tuberculosis (TB) patients from Delhi, India. All patients received linezolid as part of their anti-TB regimen. The high percentage of favourable treatment outcomes in the study led Singla et al. [1] to conclude that “Linezolid could have played a key role”. However, in our opinion, conclusions on the role of a single agent, such as linezolid, are difficult to draw from a series of cases without controls, in which every patient received linezolid in addition to an injectable antimycobacterial agent and a fluoroquinolone. Indeed, the important …