Usefulness of the BACES score in nontuberculous mycobacterial pulmonary disease for various clinical outcomes

OPTIMA: An Open-Label, Noncomparative Pilot Trial of Inhaled Molgramostim in Pulmonary Nontuberculous Mycobacterial Infection

Rationale: Inhaled granulocyte-macrophage colony-stimulating factor (GM-CSF) has been proposed as a potential immunomodulatory treatment for nontuberculous mycobacterial (NTM) infection.Objectives: This open-label, noncomparative pilot trial investigated the efficacy and safety of inhaled GM-CSF (molgramostim nebulizer solution) in patients with predominantly treatment-refractory pulmonary NTM infection (Mycobacterium avium complex [MAC] and M. abscessus [MABS]), either in combination with ongoing guideline-based therapy (GBT) or as monotherapy in patients who had stopped GBT because of lack of efficacy or intolerability.Methods: Thirty-two adult patients with refractory NTM infection (MAC, n = 24; MABS, n = 8) were recruited into two cohorts: those with (n = 16) and without (n = 16) ongoing GBT. Nebulized molgramostim 300 μg/d was administered over 48 weeks. Sputum cultures and smears and clinical assessments (6-min-walk distance, symptom scores, Quality of Life-Bronchiectasis Questionnaire score, and body weight) were collected every 4 weeks during treatment and 12 weeks after the end of treatment. The primary endpoint was sputum culture conversion, defined as three consecutive monthly negative cultures during the treatment period.Results: Eight patients (25%) achieved culture conversion on treatment (seven [29.2%] patients with MAC infection, one [12.5%] patient with MABS infection); in four patients, this was durable after the end of treatment. Of the 24 patients with MAC infection, an additional 4 patients had a partial response, converting from smear positive at baseline to smear negative at the end of treatment, and time to positivity in liquid culture media increased. Two of these patients sustained negative cultures from the end of treatment. Other clinical endpoints were unchanged. Serious adverse events were mainly pulmonary exacerbations or worsening NTM infection. Three deaths, not treatment related, were reported.Conclusions: In this population of patients with severe NTM disease, molgramostim was safe and well tolerated. Sputum culture conversion rates for patients with MAC infection (29.2%) were greater than reported for similar refractory MAC cohorts managed with GBT alone. Less benefit was seen for MABS infection. No serious safety concerns were identified. Further evaluation in a larger cohort is warranted.Clinical trial registered with www.clinicaltrials.gov (NCT03421743).

Rates and Risk Factors of Progression in Patients With Nontuberculous Mycobacterial Pulmonary Disease: Secondary Analysis of a Prospective Cohort Study

BACKGROUND

The clinical course of nontuberculous mycobacterial pulmonary disease (NTM-PD) is varied, and a watchful waiting management strategy is appropriate for a subset of patients. Understanding disease progression and risk factors for progression is essential for deciding on an appropriate follow-up strategy.

RESEARCH QUESTION

What is the rate of NTM-PD progression, and what are the predictors of progression?

STUDY DESIGN AND METHODS

Patients with NTM-PD who were enrolled in a prospective observational cohort study between July 1, 2011, and December 31, 2022, were included in this analysis. Clinical, bacterial, laboratory, and radiographic data were collected at enrollment and then regularly during follow-up. NTM-PD progression was defined as either the initiation of treatment or the clinician's intention to treat. The rate of progression was calculated and the predictors for progression were analyzed.

RESULTS

Of the 477 patients enrolled, NTM-PD progressed in 192 patients over a median follow-up of 5.4 years. The incidence of NTM-PD progression was 11.0 cases per 100 person-years (95% CI, 9.5-12.7 cases per 100 person-years). The proportion of patients experiencing disease progression was 21.4% at 1 year, 33.8% at 3 years, and 43.3% at 5 years. The final multivariable analysis model identified female sex (adjusted hazard ratio [aHR], 1.69; 95% CI, 1.19-2.39), elevated erythrocyte sedimentation rate (aHR, 1.79; 95% CI, 1.31-2.43), FEV1 % predicted (aHR, 0.89; 95% CI, 0.82-0.96), and the presence of a cavity (aHR, 2.78; 95% CI, 2.03-3.80) as predictors of progression.

INTERPRETATION

About half of patients with NTM-PD experienced progression during an observation period of > 5 years. Patients with risk factors for progression should be observed closely.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01616745; URL: www.

CLINICALTRIALS

gov.

External Validation of the BACES Score in Canadian Patients With Nontuberculous Mycobacterial Pulmonary Disease

BACKGROUND

The clinical course of nontuberculous mycobacterial pulmonary disease (NTM-PD) can be variable and difficult to predict. Recently, the BACES score was developed as a tool to predict all-cause mortality in patients with NTM-PD. This score is calculated based on five patient characteristics (BMI, age, cavity, erythrocyte sedimentation rate, and sex), and higher scores portend worse prognosis. Although the BACES score has been validated in a cohort of South Korean patients, it has not yet been validated in other settings or ethnic groups.

RESEARCH QUESTION

How well does the BACES mortality score perform in a cohort of Canadian patients with NTM-PD?

STUDY DESIGN AND METHODS

We performed a single-center retrospective chart review. Patients who were seen between July 2003 and June 2021 were eligible for inclusion if they met guideline-based diagnostic criteria for NTM-PD and were excluded if any component of the BACES score was missing. To assess the model's discriminatory performance, we compared Kaplan-Meier curves between risk groups and calculated Harrell's C index. To assess calibration, we used a graphical calibration curve.

RESULTS

The cohort included 435 patients with a median follow-up of 5.8 years. The median age was 64 years and 74% were female. Based on the BACES scores, patients were classified into three risk groups: low, moderate, or high. Survival curves showed clear separation of the risk groups. Harrell's C index was 0.733 in the study cohort, indicating moderate to good discriminatory performance, although this was lower than the value reported in the derivation cohort (0.812). The graphical calibration curve showed a tendency of the BACES model to underpredict mortality.

INTERPRETATION

The BACES model was evaluated in a multicultural cohort of Canadian patients and demonstrated good discriminatory performance but suboptimal calibration, which may be due to population differences, the use of dichotomized variables in model construction, or both.

Effect of multidrug therapy on the prognosis of Mycobacterium avium complex pulmonary disease

Multidrug therapy for Mycobacterium avium complex pulmonary disease (MAC-PD) results in negative sputum cultures. However, the prognostic value of this treatment approach remains unclear. This study aimed to clarify whether multidrug therapy reduces the incidence of events related to MAC-PD and improves the mortality rate. Patients who met the diagnostic criteria for MAC-PD at our hospital between 2003 and 2019 were retrospectively evaluated using medical records. Events related to MAC-PD were defined as hospitalisation for haemoptysis or respiratory infection and the development of chronic respiratory failure. There were 90 and 108 patients in the multidrug and observation groups, respectively. The median observation period was 86 months. Intergroup differences in body mass index, proportion of patients with cavities, and erythrocyte sedimentation rate were not significant. However, the observation group was older with a higher mean age (multidrug group: 62 years, observation group: 69 years; P < 0.001) and had a higher proportion of male patients (multidrug group: 13/90 [14.4%], observation group: 35/108 [32.4%]; P < 0.01). Furthermore, intergroup differences in the incidence of events related to MAC-PD (multidrug group: 26.69/1000 person-years, observation group: 25.49/1000 person-years), MAC-PD-associated mortality rate (multidrug group: 12.13/1000 person-years, observation group: 12.74/1000 person-years), and total mortality (multidrug group: 24.26/1000 person-years, observation group: 29.50/1000 person-years) were not significant. Many patients relapse even after multidrug therapy, and our findings suggest that multidrug therapy has no effect in preventing the onset of respiratory events or prolonging life expectancy.

The Clinical Implications of Serum Carbohydrate Antigen 19-9 Levels in Patients with Nontuberculous Mycobacteria Pulmonary Disease

Serum carbohydrate antigen 19-9 (CA19-9) levels can increase in nontuberculous mycobacteria pulmonary disease (NTM-PD), and the levels correlate with disease activity. We compared the clinical characteristics of NTM-PD patients with and without elevated CA19-9 levels and evaluated its association with antibiotic response in a retrospective study of NTM-PD patients diagnosed between January 1994 and December 2020. We analyzed 1112 patients who had serum CA19-9 measured: 322 with elevated CA19-9 and 790 with normal CA19-9. The erythrocyte sedimentation rate and C-reactive protein levels were significantly higher in the elevated CA19-9 group (p < 0.001 and p = 0.029, respectively). The 1-year culture conversion rate after antibiotics did not differ between the elevated (n = 206) and normal (n = 377) CA19-9 groups (80% vs. 72%, p = 0.055). Analysis of a subset of 434 patients revealed that current smoking, bronchiectasis, acid-fast bacilli smear positivity, and the M. abscessus strain significantly reduced microbiological cure rates. Serum CA 19-9 levels did not have a significant association with microbiological cure in a multivariate analysis. These findings suggest that the role of serum CA19-9 in predicting antibiotic treatment outcomes is limited, and that elevated CA19-9 does not necessarily indicate a poor outcome.

Spontaneous Cultural Conversion Rate of Mycobacterium avium Complex Pulmonary Disease Based on BACES Severity

BACKGROUND

Only a few clinical factors can aid in predicting spontaneous culture conversion (SCC) in patients with Mycobacterium avium complex-pulmonary disease (MAC-PD). In this study, we aimed to evaluate whether the rate of SCC varies according to the severity of the disease in MAC-PD patients.

METHODS

We retrospectively classified 373 MAC-PD patients who had undergone watchful waiting without antibiotics based on the severity assessment using the 'body mass index (BMI), age, cavity, erythrocyte sedimentation rate (ESR), and sex (BACES)' criteria. We evaluated the rate of SCC in MAC-PD patients based on BACES severity and analyzed the relevant factors. Results: Of 373 patients, 153 (41%) achieved SCC without antibiotics during a median follow-up of 48.1 months. There was a trend toward a higher SCC rate in patients with lower BACES severity: 48% (87/183), 37% (58/157), and 24% (8/33) in the mild, moderate, and severe BACES groups, respectively. In addition, a favorable outcome, defined as maintaining SCC or having two consecutive negative sputum cultures until the last follow-up date, was also more common in patients with lower BACES severities of 53% (97/183), 34% (54/157), and 18% (6/33) in the mild, moderate, and severe BACES groups, respectively. In multivariate analysis, moderate BACES (hazard ratio [HR] = 0.63; 95% confidence interval [CI] 0.44-0.91; p = 0.013) and severe BACES (HR 0.37; 95% CI 0.16-0.90; p = 0.028) had a significantly negative impact on favorable outcomes compared to mild BACES.

CONCLUSIONS

Lower BACES severity may be associated with SCC in MAC-PD patients.