Linezolid in the treatment of disseminated nontuberculous mycobacterial infection in anti-interferon-gamma autoantibody-positive patients.

Disseminated nontuberculous mycobacterial (NTM) infection is the most common feature in patients positive for anti-interferon-gamma autoantibody (IFN-gamma Ab). The condition is a form of anticytokine autoantibody syndrome. It is difficult to treat because of multiple drug resistance in mycobacteria. Linezolid is active against NTM in vitro; however clinical experience using this drug against NTM is limited. We report our experience using linezolid as part of an antimycobacterial regimen for treatment of 16 refractory cases of disseminated NTM at Srinagarind University Hospital, Khon Kaen, between September 2008 and December 2012. Complete resolution of signs and symptoms was seen in eight patients (50%) on linezolid therapy. Partial or no improvement was seen in a further four (25%) and three (19%) cases, respectively. Five (31%) patients developed an adverse reaction to linezolid; three of whom received 600 mg of linezolid twice daily. The study demonstrated the modest efficacy of linezolid for treating patients with a protracted course of disseminated-NTM; however, adverse effects were significant, especially for those on the high-dosage regimen.