1355. Efficacy and Tolerability of Linezolid Adjunctive Treatment for Nontuberculous Mycobacterial Infection in Patients with Acquired Anti-Interferon-Gamma Autoantibody.

Chavapradit, Natthakit; Suputtamongkol, Yupin; Angkasekwinai, Nasikarn; Phoompoung, Pakpoom; Chirapapisan, Niphon; Foongladda, Suporn

Background Despite a long duration of combined oral antimycobacterial drugs, relapse/ reinfection of nontuberculous mycobacteria (NTM) is common among patients with anti-interferon gamma autoantibodies (anti-IFN-γ auto-Abs). Methods We reported here, an interim analysis of the prospective study of 25 patients with anti-IFN-γ auto-Abs, who received oral linezolid (LZD) adjunctive treatment for their NTM infections, at Siriraj Hospital, Bangkok, Thailand, between December 2017 and April 2019. Results 8 patients (32%) were male, with a median age of 52.5 years. NTM identified among them included Mycobacterium abscessus (n = 19), M. avium complex (MAC) (n = 2), M. fortuitum (n = 2), M. kansasii (n = 1), and both M. abscessus and MAC (n = 1). The median duration of follow-up was 11 months (range 1.6–15 months). LZD 600 mg/day was given until clinical remission, then reduced to 300 mg/day for a total duration of at least 9 months. Other patient's managements, including choice and duration of other antimycobacterial therapy were determined by the attending physician. Clinical remission was achieved, and LZD was discontinued at 9 months in 10 patients. NTM infection remained active and LZD was continued to 12 months in 4 patients. Two patients only completed 6 months of LZD. Culture proven relapse of M. abscessus occurred in 3 patients during LZD treatment, and 1 patient developed M. haemophilum infection after discontinuation of all drugs for 3 months. One patient was retreated with intravenous antimycobacterial drugs based on clinical suspicious of relapse NTM infection. LZD-related serious adverse events leading to discontinue of LZD occurred in 5 patients; severe myelosuppression (n = 1), peripheral neuropathy (n = 2), exfoliative dermatitis (n = 1), and idiopathic increased intracranial pressure (n = 1). Anemia occurred in 3 patients during the 600 mg LZD once-daily treatment period. No patient developed anemia after LZD was adjusted to 300 mg twice daily. The rate of peripheral neuropathy was similar throughout the study period. Conclusion LZD might reduce the rate of relapsed/ reinfection of NTM infection in these patients. LZD 300 mg twice daily was less toxicity and more tolerable than 600 mg once daily. Long-term study with this modified regimen is now on-going. Disclosures All authors: No reported disclosures.

BANGKOK (Thailand); MYCOBACTERIAL diseases; LINEZOLID; INTRACRANIAL pressure; PERIPHERAL neuropathy; MYCOBACTERIUM; BURULI ulcer

Open Forum Infectious Diseases, 2019, Vol 6, pS490

2328-8957

Academic Journal

10.1093/ofid/ofz360.1219