1488. Relationship Between Culture Conversion and Clinical Outcomes in Patients With Mycobacterium abscessus (MAB) Lung Disease: A Systematic Literature Review

BACKGROUND: Treatment of MAB lung disease is difficult, and currently there is no consensus on the best course of treatment. We examined the relationship between culture conversion and clinical outcomes among patients with MAB lung disease. METHODS: English-language MAB lung disease studies with ≥10 patients and reporting culture conversion and/or an outcome of interest (eg, changes in symptoms, lung function, quality of life, and/or radiography) were identified from Embase, PubMed, relevant congress abstracts, and the Cochrane Library (data cutoff, September 24, 2019) using the National Institute for Health and Clinical Excellence guidance for systematic literature reviews. Two independent reviewers screened 1,551 indexed records; relevant data were extracted and are reported as population-weighted means. RESULTS: No study directly correlated culture conversion with a change in symptoms. In 10 studies (N=869) reporting overall symptoms and culture conversion separately, 72.5% of patients (range 36%–96%) reported symptom improvement and 56.5% (range, 13%-99%) achieved culture conversion; a weak trend between symptomatic improvement and higher culture conversion rates (R(2)=0.36) was observed. Three additional studies (N=106) reported symptomatic improvement and culture conversion as a single measurement (49.6%, range, 25%-81%). Limited data indirectly correlated improvement in cough, dyspnea, hemoptysis, sputum production, and fatigue with culture conversion (1-2 studies each). Two studies directly correlated improved lung function (N=62) with culture conversion, and one study indirectly reported improved health-related quality of life (N=47) with culture conversion; no study reported radiology outcomes in relation to culture conversion. CONCLUSION: This systematic literature review underscores the lack of data correlating clinical outcomes and culture conversion in patients with MAB lung disease. Limitations include a small number of studies, inconsistencies/non-reporting of methods, and poorly defined outcomes. Although indirect data indicate a weak correlation between symptom improvement and culture conversion, more evidence is needed to demonstrate a clinical outcome benefit associated with culture conversion. DISCLOSURES: Patrick A Flume, MD, Insmed Incorporated (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member) Kevin C Mange, MD, MSCE, Insmed Incorporated (Employee) Zhanna Jumadilova, MD, Insmed Incorporated (Employee) Kristan B Cline, PhD, Insmed Incorporated (Employee) Kevin L Winthrop, MD, MPH, Insmed Incorporated (Consultant, Grant/Research Support)