Cure rates in nontuberculous mycobacterial pulmonary disease

Introduction: guidelines for nontuberculous mycobacterial pulmonary disease (NTMPD) treatment are mainly based on cohort studies and data on M. avium complex (MAC). Methods: retrospective analysis of all Croatian residents with respiratory NTM isolate from 2006 to 2016. ATS/IDSA guidelines were used for NTMPD definition. Cure was defined as multiple negative cultures at the end of treatment or at 12 months follow-up in case of shorter regimens. Regimens were grouped as: tuberculosis (TB), adequate NTM (NTM), Results: 137 cases of NTMPD (mean age 66.5; 52.6% males) were mostly caused by M.xenopi (n=54), and MAC (n=53). Median follow up was 60.47 months. 5-year all-cause mortality amounted to 36.5%. 38/137 had cavitary form; 47/114 were smear positive. Therapy was started in 98 (71.5%) cases - TB in 43.9%, NTM in 31.6%, and short NTM in 15.3% and cases. Cure was achieved in 64.7%, 82.8%, and 64.3% of patients finishing TB, NTM, and short NTM regimen, respectively. Patients receiving adequate therapy had 4x higher chance (p=0.012) of cure compared to ones receiving other regimen or no therapy. Therapy was started in 34 (89.5%) cases of cavitary NTMPD. Cure was achieved in 63.6% on TB and 83.3% on NTM therapy. 43 (91.5%) smear positive cases received treatment. Cure was achieved in 46.7% on TB and 75% on NTM therapy. In smear negative patients, regardless of NTMPD form, all regimens resulted with similar cure rates (over 80%). Conclusions: smear status and cavitary disease were major factors influencing therapy initiation. Adequate NTM regimens significantly improved overall cure rate but seem to be of highest importance in „heavier“disease forms (i.e. smear positive and/or cavitary).