CLINICAL CHARACTERISTICS OF PATIENTS TREATED WITH ANTIMYCOBACTERIALS VS NO ANTIMYCOBACTERIALS IN NONCAVITARY MYCOBACTERIUM AVIUM COMPLEX PULMONARY DISEASE

SESSION TITLE: Respiratory Infections: It's Not Just About AntimicrobialsSESSION TYPE: Original InvestigationsPRESENTED ON: 10/16/2022 10:30 am - 11:30 amPURPOSE: Initiation of treatment for noncavitary Mycobacterium Avium Complex pulmonary disease (MAC-PD) remains a difficult clinical decision. Current recommendations include a prolonged course of at least three antimycobacterial drugs. There is limited data regarding characteristics of patients with fibronodular, bronchiectatic MAC-PD who are treated with bronchial hygiene measures alone compared to those who receive antimycobacterial agents. We aimed to describe the characteristics and outcomes of those were treated versus untreated with antimycobacterials for MAC-PD.METHODS: We conducted a retrospective cohort study of patients at Mayo Clinic who were diagnosed with MAC-PD based on ATS/IDSA criteria from March 2018 through December 2019. Patients were excluded if they had cavitary disease, were previously treated for MAC-PD, had HIV, or had extrapulmonary manifestations. We extracted information on patient demographics plus clinical, radiologic and microbiologic data.RESULTS: Of the 29 patients who met our inclusion criteria, 15 were treated and 14 were untreated. Most patients (96.6%) had M. avium complex and one patient had M. chimaera. The mean age was 66.2 in the treated group and 73 in the untreated group (p=0.07). Both groups had patients that were sputum smear positive at the time of diagnosis (41.7% treated group, 33.3% untreated group; p = 0.22). The most commonly reported symptoms at diagnosis were cough, dyspnea and fatigue. The treated group had longer, more routine followup than the untreated group (mean 22 months and 17.1 months, respectively; p = 0.05). Of patients with a total of 24 months of followup (n = 17), only two patients were reported to be asymptomatic, one from each group. All patients who received antimycobacterials had clearance of their mycobacterial sputum cultures, with a mean of 12 months and return to culture positivity in 1 patient. A total of 6 patients in the untreated group had documented clearance of mycobacterial cultures with a mean of 9 months (p = 0.42). Two untreated patients had documented persistent culture positivity at 24 months. There was 1 treated patient who experienced return to culture positivity and 2 untreated patients who had culture positivity after previous clearance. In both groups, clinical and radiologic findings remained stable.CONCLUSIONS: While patients with fibronodular, bronchiectatic MAC-PD who received antimycobacterials had improved mycobacterial sputum culture clearance, those treated only with airway clearance demonstrated similar clinical and radiographic stability in comparison to those who were treated with antimycobacterials in our cohort.CLINICAL IMPLICATIONS: In select patients with noncavitary MAC-PD, clinical observation with bronchial hygiene measures may be a reasonable alternative to compared to antimycobacterial therapy. Further studies are needed to better define which patients would benefit most from antimycobacterials.DISCLOSURES: Short Respiratory Advisory Board relationship with DiaSorin Molecular Please note: $5001 - $20000 by Patricio Escalante, value=Honoraria given to institutionNo relevant relationships by Renuka Reddy KattaNo relevant relationships by Paige MartyNo relevant relationships by Kelly PenningtonNo relevant relationships by Maleeha Shah SESSION TITLE: Respiratory Infections: It's Not Just About Antimicrobials SESSION TYPE: Original Investigations PRESENTED ON: 10/16/2022 10:30 am - 11:30 am PURPOSE: Initiation of treatment for noncavitary Mycobacterium Avium Complex pulmonary disease (MAC-PD) remains a difficult clinical decision. Current recommendations include a prolonged course of at least three antimycobacterial drugs. There is limited data regarding characteristics of patients with fibronodular, bronchiectatic MAC-PD who are treated with bronchial hygiene measures alone compared to those who receive antimycobacterial agents. We aimed to describe the characteristics and outcomes of those were treated versus untreated with antimycobacterials for MAC-PD. METHODS: We conducted a retrospective cohort study of patients at Mayo Clinic who were diagnosed with MAC-PD based on ATS/IDSA criteria from March 2018 through December 2019. Patients were excluded if they had cavitary disease, were previously treated for MAC-PD, had HIV, or had extrapulmonary manifestations. We extracted information on patient demographics plus clinical, radiologic and microbiologic data. RESULTS: Of the 29 patients who met our inclusion criteria, 15 were treated and 14 were untreated. Most patients (96.6%) had M. avium complex and one patient had M. chimaera. The mean age was 66.2 in the treated group and 73 in the untreated group (p=0.07). Both groups had patients that were sputum smear positive at the time of diagnosis (41.7% treated group, 33.3% untreated group; p = 0.22). The most commonly reported symptoms at diagnosis were cough, dyspnea and fatigue. The treated group had longer, more routine followup than the untreated group (mean 22 months and 17.1 months, respectively; p = 0.05). Of patients with a total of 24 months of followup (n = 17), only two patients were reported to be asymptomatic, one from each group. All patients who received antimycobacterials had clearance of their mycobacterial sputum cultures, with a mean of 12 months and return to culture positivity in 1 patient. A total of 6 patients in the untreated group had documented clearance of mycobacterial cultures with a mean of 9 months (p = 0.42). Two untreated patients had documented persistent culture positivity at 24 months. There was 1 treated patient who experienced return to culture positivity and 2 untreated patients who had culture positivity after previous clearance. In both groups, clinical and radiologic findings remained stable. CONCLUSIONS: While patients with fibronodular, bronchiectatic MAC-PD who received antimycobacterials had improved mycobacterial sputum culture clearance, those treated only with airway clearance demonstrated similar clinical and radiographic stability in comparison to those who were treated with antimycobacterials in our cohort. CLINICAL IMPLICATIONS: In select patients with noncavitary MAC-PD, clinical observation with bronchial hygiene measures may be a reasonable alternative to compared to antimycobacterial therapy. Further studies are needed to better define which patients would benefit most from antimycobacterials. DISCLOSURES: Short Respiratory Advisory Board relationship with DiaSorin Molecular Please note: $5001 - $20000 by Patricio Escalante, value=Honoraria given to institution No relevant relationships by Renuka Reddy Katta No relevant relationships by Paige Marty No relevant relationships by Kelly Pennington No relevant relationships by Maleeha Shah