A multidisciplinary approach to the management of nontuberculous mycobacterial lung disease: a clinical perspective

Drugs for treating infections caused by non-tubercular mycobacteria: a narrative review from the study group on mycobacteria of the Italian Society of Infectious Diseases and Tropical Medicine

BACKGROUND

Non-tuberculous mycobacteria (NTM) are generally free-living organism, widely distributed in the environment, with sporadic potential to infect. In recent years, there has been a significant increase in the global incidence of NTM-related disease, spanning across all continents and an increased mortality after the diagnosis has been reported. The decisions on whether to treat or not and which drugs to use are complex and require a multidisciplinary approach as well as patients' involvement in the decision process.

METHODS AND RESULTS

This review aims at describing the drugs used for treating NTM-associated diseases emphasizing the efficacy, tolerability, optimization strategies as well as possible drugs that might be used in case of intolerance or resistance. We also reviewed data on newer compounds highlighting the lack of randomised clinical trials for many drugs but also encouraging preliminary data for others. We also focused on non-pharmacological interventions that need to be adopted during care of individuals with NTM-associated diseases CONCLUSIONS: Despite insufficient efficacy and poor tolerability this review emphasizes the improvement in patients' care and the needs for future studies in the field of anti-NTM treatments.

Pharmacotherapeutic Considerations in the Treatment of Nontuberculous Mycobacterial Infections: A Primer for Clinicians

Nontuberculous mycobacteria (NTM) can cause a variety of infections, including serious pulmonary disease. Treatment encompasses polypharmacy, with a targeted regimen of 2-5 active medications, depending on site of infection, species, and clinical characteristics. Medications may include oral, intravenous, and inhalational routes. Medication acquisition can be challenging for numerous reasons, including investigational status, limited distribution models, and insurance prior authorization. Additionally, monitoring and managing adverse reactions and drug interactions is a unique skill set. While NTM is primarily medically managed, clinicians may not be familiar with the intricacies of medication selection, procurement, and monitoring. This review offers insights into the pharmacotherapeutic considerations of this highly complex disease state, including regimen design, medication acquisition, safety monitoring, relevant drug-drug interactions, and adverse drug reactions.

Treatment Approaches to Mycobacterium abscessus Pulmonary Disease

Mycobacterium abscessus pulmonary disease is highly antibiotic-resistant, and the current armamentarium of antibiotics yields poor treatment outcomes with significant drug toxicity. Macrolide susceptibility is a key prognostic factor. Optimal drug combinations, duration of therapy, and management of refractory disease are unknown. Surgical resection, performed at centers with experience in surgical management of nontuberculous mycobacterial pulmonary disease, may produce favorable outcomes in select patients. Multiple emerging therapeutic candidates hold promise for more efficacious and tolerable treatment options.

Incremental mortality associated with nontuberculous mycobacterial lung disease among US Medicare beneficiaries with chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common comorbidity in patients with nontuberculous mycobacterial lung disease (NTMLD). Both conditions are associated with increased morbidity and mortality, but data are lacking on the additional burden associated with NTMLD among patients with COPD. Thus, the goal of this study was to assess the incremental mortality risk associated with NTMLD among older adults with COPD.

METHODS

A retrospective cohort study was conducted using the US Medicare claims database (2010-2017). Patients with preexisting COPD and NTMLD (cases) were matched 1:3 by age and sex with patients with COPD without NTMLD (control patients). Patients were followed up until death or data cutoff (December 31, 2017). Incremental risk of mortality was evaluated by comparing the proportions of death, annualized mortality rate, and mortality hazard rate between cases and control patients using both univariate and multivariate analyses adjusting for age, sex, comorbidities, and COPD severity.

RESULTS

A total of 4,926 cases were matched with 14,778 control patients. In univariate analyses, a higher proportion of cases (vs. control patients) died (41.5% vs. 26.7%; P < 0.0001), unadjusted annual mortality rates were higher among cases (158.5 vs. 86.0 deaths/1000 person-years; P < 0.0001), and time to death was shorter for cases. This increased mortality risk was also reflected in subsequent multivariate analyses. Patients with COPD and NTMLD were more likely to die (odds ratio [95% CI], 1.39 [1.27-1.51]), had higher mortality rates (rate ratio [95% CI], 1.36 [1.28-1.45]), and had higher hazard of death (hazard ratio [95% CI], 1.37 [1.28-1.46]) than control patients.

CONCLUSIONS

The substantial incremental mortality burden associated with NTMLD in patients with COPD highlights the importance of developing interventions targeting this high-risk group and may indicate an unmet need for timely and appropriate management of NTMLD.

Necroptosis-related subtypes are associated with bronchiectasis in pulmonary non-tuberculous mycobacteria-infected patients: a perspective based on transcriptomic analysis

The aim of this study was to explore the potential mechanisms responsible for the different manifestations of bronchiectasis in patients with pulmonary non-tuberculous mycobacteria (pNTM) infection. We found that the necroptosis level increased significantly after NTM infection. Further, the 31 pNTM-infected patients were classified into two subtypes based on necroptosis-related genes (NRGs) by unsupervised cluster analysis. After that, we compared the differences in clinical parameters, immune cell infiltration, and gene expression between the two subtypes. We observed that the high-necroptosis subtype possessed higher CT scores for bronchiectasis extent (P = 0.008) and severity (P = 0.023). And, more neutrophil infiltration in the high-necroptosis subtype was demonstrated both by the CIBERSORT algorithm and by blood neutrophil count (P = 0.001). Next, 688 differentially expressed genes (DEGs) between two subtypes were identified. To explore the portion in DEGs that might contribute to bronchiectasis, we intersected the DEGs with two gene modules. These two gene modules were identified as the most associated with CT scores for bronchiectasis extent and severity by weighted gene co-expression network analysis (WGCNA). Ninety-three intersection genes were obtained. Finally, 7 hub genes including ACSL1, ANXA3, DYSF, HK3, SLC11A1, STX11, and TLR4 were further screened out by machine learning algorithms and protein-protein interaction network analysis. These results suggested that the differential levels of necroptosis in pNTM patients might lead to differential extent and severity of bronchiectasis on radiographic imaging. This process might be associated with neutrophil infiltration and the involvement of seven hub genes.

Case Report: Kampo Medicine for Non-tuberculous Mycobacterium Pulmonary Disease

Background: While the number of pulmonary tuberculosis cases has decreased, increase in non-tuberculous mycobacterium pulmonary disease (NTM-PD) is a global problem. Guideline-based therapy for NTM-PD sometimes causes complications that prevent treatment completion, and there are many cases of relapse even if the treatment can be completed. In addition to antibacterial treatment, care of host risk factors, such as aging, lean physique and immunosuppressive state, is also very important for the management of NTM-PD. In Japan, Kampo medicine, a traditional Japanese herbal formulation, used alone or in combination with standard multidrug therapy for NTM-PD, has been found to be effective for such cases.

Case Presentation: A 77-year-old lean woman had been diagnosed with Mycobacterium intracellulare pulmonary infection 6 years earlier, and had received the standard multidrug treatment 5 years later at a former hospital due to worsening of her symptoms of cough, breathlessness and hemoptysis. However, the treatment was discontinued within a year due to the development of adverse events. She refused the guideline-based antibacterial treatment, and asked for Kampo medicine instead. Bukuryoshigyakuto was subsequently prescribed, which led to cough and sputum, especially hemosputum, being well controlled. With 3 years of Kampo medicine treatment, she gained weight and her hemosputum disappeared. High-resolution computed tomography images showed improvement in her lung condition, and her sputum smear culture was negative for acid-fast bacillus.

Conclusion: Various kinds of Kampo medicines have been used empirically for NTM-PD in Japan. A literature review from 1992 to 2020 showed that hozais, in particular, seem to be key drugs for the treatment of host NTM-PD risk factors. Kampo medicines can contribute to comprehensive treatment for NTM-PD management that does not rely solely on antibacterial drugs.

Nontuberculous mycobacterial lung disease caused by Mycobacterium avium complex - disease burden, unmet needs, and advances in treatment developments

INTRODUCTION

Nontuberculous mycobacterial (NTM) lung disease (LD) is the most common clinical manifestation of NTM infection and is a growing health concern. Up to 85% of NTM-LD cases are caused by Mycobacterium avium complex (MAC). Increased awareness of NTM-LD caused by MAC is needed as patients with this disease experience substantial burden and unmet treatment needs.

AREAS COVERED

This review provides clinicians and regulatory and healthcare decision makers an overview of the clinical, economic, and humanistic burden of NTM-LD and the unmet treatment needs faced by patients and clinicians. The review focuses on NTM-LD caused by MAC. A summary of the 2020 NTM guidelines specifically for MAC-LD and an overview of novel treatment options, including amikacin liposome inhalation suspension (ALIS) as the first approved therapy for refractory MAC-LD, and investigational drugs in testing phase are provided.

EXPERT OPINION

Key advancements in NTM-LD management include recent updates to clinical practice guidelines, approval of ALIS for the treatment of refractory MAC-LD, and ongoing clinical trials of investigational treatments. Yet opportunities still exist to improve patient outcomes, including development of better screening tools, such as reliable and responsive biomarkers to help identify high-risk patients, and addressing unmet treatment needs.