Prognostic factors associated with long-term mortality in 1445 patients with nontuberculous mycobacterial pulmonary disease: a 15-year follow-up study

Comprehensive Management Algorithm for Mycobacterium avium Complex Pulmonary Disease in the Real-World Setting

The management of Mycobacterium avium complex pulmonary disease (MAC-PD) is challenging because of limited efficacy and frequent adverse events associated with standard treatments. The 2020 guidelines from the American Thoracic Society, European Respiratory Society, European Society of Clinical Microbiology and Infectious Diseases, and Infectious Diseases Society of America provide recommendations, but real-world adherence is often hindered by these issues, leading many patients to be unable to complete standard therapy. This review proposes a comprehensive management algorithm for MAC-PD, emphasizing multidisciplinary approaches and integrating nonantimicrobial management before, during, and after drug treatment to enhance patient outcomes. When a patient presents with chronic respiratory symptoms suggestive of nontuberculous mycobacteria, clinicians should follow a guideline-based approach to diagnosis, as diagnostic delays are common because of nonspecific symptoms. Proper evaluation should determine the disease phenotype (existence of cavitary lesions), as it influences treatment choices. Airway clearance, nutritional support, and management of underlying conditions are essential nonantimicrobial components. Regular outpatient monitoring helps detect disease progression and optimize treatment. Treatment strategies vary based on disease severity. For noncavitary nodular bronchiectatic disease, a thrice-weekly regimen is preferred because of better tolerability. Severe cases or those with cavitary forms may require daily treatment with additional aminoglycosides. Amikacin liposome inhalation suspension is recommended for patients not responding to standard regimens after 6 months. Recent research addresses drug intolerance, suggesting alternatives such as a two-drug regimen without rifamycin in certain cases. Consultation with nontuberculous mycobacteria specialists is advised for complex cases, particularly those with macrolide resistance or requiring surgical intervention. The algorithm emphasizes shared decision making, patient education, and family support to improve adherence and outcomes.

Relationship between culture conversion and clinical outcomes in nontuberculous mycobacterial pulmonary disease: Narrative review

PURPOSE

Nontuberculous mycobacterial pulmonary disease (NTMPD) is a chronic, often progressive condition associated with a significant symptom burden and increased mortality. Goals of NTMPD treatment include microbiological eradication, symptom reduction, improved quality of life (QoL), and preventing disease progression. Antibiotics are used to reduce microbial burden, and cultures of sputum are used to guide treatment. However, it is unclear whether achieving culture-negative status (often called "culture conversion") is associated with improved clinical outcomes. Studies use a variety of measures including symptom burden, radiological status, lung function, 6-min walk test distance, QoL assessments, and mortality to evaluate clinical outcomes related to changes in how patients feel, function, and survive. There is strong interest in more clearly understanding which clinical benefits may be associated with culture conversion. As NTMPD can cause sustained structural lung damage and declines in long-term pulmonary function, it is important to have clear evidence if prevention of these morbidities is associated with culture conversion.

METHODS

This targeted literature review summarizes the published evidence regarding associations between sputum culture conversion and clinical outcomes in patients with NTMPD. Identified studies used varying definitions of culture conversion and treatment success, making interpretation of outcomes across studies challenging.

RESULTS

Although some studies suggest an association between culture conversion and aspects of clinical improvement, overall, there are currently few high-quality studies supporting a link.

CONCLUSION

Further clarification of the relationship between culture conversion and clinical outcomes would be helpful in improving clinical monitoring and therapeutic decision-making during the treatment of patients with NTMPD.

Interplay of mycobacterium abscessus and Pseudomonas aeruginosa in experimental models of coinfection: Biofilm dynamics and Host immune response

The incidence of infection by nontuberculous mycobacteria, mainly Mycobacterium abscessus, is increasing in patients with cystic fibrosis and other chronic pulmonary diseases, leading to an accelerated lung function decline. In most cases, M. abscessus coinfects Pseudomonas aeruginosa, the most common pathogen in these conditions. However, how these two bacterial species interact during infection remains poorly understood. This study explored their behaviour in three relevant pathogenic settings: dual-species biofilm development using a recently developed method to monitor individual species in dual-species biofilms, coinfection in bronchial epithelial cells, and in vivo coinfection in the Galleria mellonella model. The results demonstrated that both species form stable mixed biofilms and reciprocally inhibit single-biofilm progression. Coinfections in bronchial epithelial cells significantly decreased cell viability, whereas in G. mellonella, coinfections induced lower survival rates than individual infections. Analysis of the immune response triggered by each bacterium in bronchial epithelial cell assays and G. mellonella larvae revealed that P. aeruginosa induces the overexpression of proinflammatory and melanization cascade responses, respectively. In contrast, M. abscessus and P. aeruginosa coinfection significantly inhibited the immune response in both models, resulting in worse consequences for the host than those generated by a single P. aeruginosa infection. Overall, this study highlights the novel role of M. abscessus in suppressing immune responses during coinfection with P. aeruginosa, emphasizing the clinical implications for the management of cystic fibrosis and other pulmonary diseases. Understanding these interactions could inform the development of new therapeutic strategies to mitigate the severity of coinfections in vulnerable patients.

Toward a Bactericidal Oral Drug Combination for the Treatment of Mycobacterium abscessus Lung Disease

Treatment of Mycobacterium abscessus lung disease relies on underperforming drug combinations and includes parenteral, poorly tolerated, and bacteriostatic antibiotics. We posit that safe, oral, and bactericidal regimens are needed to improve cure rates and shorten treatment. Here, we combined oral representatives of three well-tolerated bactericidal drug classes, the β-lactam tebipenem (together with the β-lactamase inhibitor avibactam), the fluoroquinolone moxifloxacin, and the rifamycin rifabutin, and profiled the combination in vitro and in vivo. The combination potentiated bactericidal activity of its components against replicating M. abscessus and retained bactericidal activity against the nonreplicating, drug-tolerant form of the bacterium residing in surrogate caseum. When combined, the drugs retained the ability to induce lethal secondary effects associated with the β-lactam and fluoroquinolone, including cell wall and DNA damage, increased metabolism, and generation of reactive oxygen species. Thus, the triple-drug combination appears to exert two lethal punches while suppressing bacterial reprogramming to counter the drug-induced stresses, providing a plausible rationale for the enhanced kill effect. Addition of a bacteriostatic agent resulted in drug-specific patterns of interactions with regards to bactericidal activity reflected by the lethal secondary effects. The triple-drug combination also exerted a pronounced postantibiotic effect and reduced emergence of spontaneous resistant mutants. Collectively, this work provides a combination prototype for optimization and a profiling workflow that may be useful for the development of sterilizing regimens.

The efficacy of a regimen comprising clarithromycin, clofazimine, and bedaquiline in a mouse model of chronic Mycobacterium avium lung infection

Mycobacterium avium, a leading nontuberculous mycobacterium (NTM) pathogen, causes chronic pulmonary infections, particularly in individuals with underlying lung conditions or immunosuppression. Current treatments involve prolonged multidrug regimens with poor outcomes and significant side effects, highlighting the urgent need for improved therapies. Using a BALB/c mouse model of chronic M. avium pulmonary disease, we evaluated the efficacy of individual antibiotics-clarithromycin, clofazimine, and rifabutin-and combination regimens including clarithromycin + bedaquiline and clarithromycin + clofazimine + bedaquiline. Clarithromycin demonstrated potent bactericidal activity, reducing lung bacterial burden by 2.2 log10 CFU, while clofazimine transitioned from bacteriostatic to bactericidal, achieving a 1.7 log10 CFU reduction. Rifabutin was bacteriostatic against M. avium MAC 101 but ineffective against MAC 104. The triple-drug regimen of clarithromycin + clofazimine + bedaquiline was the most effective, achieving a 3.3 log10 CFU reduction in bacterial load, with 98% clearance within the first week and continued efficacy over 8 weeks. Gross pathology confirmed these results, with granulomatous lesions observed only in untreated or rifabutin-treated mice. Combination therapy demonstrated enhanced efficacy compared to monotherapy. The findings underscore the potential of oral clarithromycin + clofazimine + bedaquiline or clarithromycin + clofazimine regimen as a promising therapeutic strategy for M. avium pulmonary disease.

The therapeutic impact of maximum chemotherapy possession days during three consecutive months in non-tuberculous mycobacterial lung disease: A real-world experience

PURPOSE

Adherence to guideline recommendations in the treatment of non-tuberculous mycobacterial lung disease (NTM-LD) is often difficult. Thus, this study aimed to investigate the impact of the integrity of NTM-LD treatment on treatment outcomes.

MATERIALS AND METHODS

The participants were screened from the National Taiwan University Hospital-Integrative Medical Database (NTUH-iMD) and the Taiwan National Health Insurance Research Database (NHIRD). The longest treatment duration during 3 consecutive months was defined as maximum chemotherapy possession days (MCPDs) and was categorized as low (28-55 days), medium (56-90 days), and maximum (≥91 days). We analyzed microbiological cure and 3-year mortality using MCPDs.

RESULTS

Low, medium, and maximum MCPD groups had 83 (19.2 %), 94 (21.8 %), and 255 (59.0 %) participants in the NTUH-iMD cohort (N = 432) and 1203 (26.5 %), 1251 (27.6 %), and 2084 (45.9 %) participants in the NHIRD cohort (N = 4538), respectively. In the NTUH-iMD cohort, multivariable analysis showed that adjusted hazard ratios (aHRs) of 3-year mortality were 0.51 (95 % CI: 0.29-0.90) and 0.29 (0.18-0.49) in medium and maximum MCPD groups compared with the low MCPD group. The trends of survival benefit by maximum MCPDs were also found in the NHIRD cohort. The maximum MCPD group had 45.9 % participants with microbiologic cure, which was significantly higher than in medium and low MCPD groups (27.7 % and 4.0 %, respectively; p < 0.001).

CONCLUSION

Maximum MCPD for NTM-LD increased microbiological cure and reduced 3-year mortality by 71 % compared with low MCPD group. Maintaining NTM-LD treatment integrity as possible might positively impact disease outcomes.

Durlobactam in combination with β-lactams to combat Mycobacterium abscessus

Mycobacterium abscessus (Mab) presents significant clinical challenges. This study evaluated the synergistic effects of a β-lactam and β-lactamase inhibitor combination against Mab and explored the underlying mechanisms. Synergy was assessed through MIC tests and time-kill studies, and binding affinities of nine β-lactams and BLIs to eight target receptors (L,D-transpeptidases [LDT] 1-5, D,D-carboxypeptidase, penicillin-binding protein [PBP] B, and PBP-lipo) were assessed using mass spectrometry and kinetic studies. Thermal stability and morphological changes were determined. Imipenem demonstrated high binding affinity to LDTs and PBPs, with extremely low inhibition constants (Ki,app; ≤0.002 mg/L for LDT1-2, ≤0.6 mg/L for PBPs), while cephalosporins, sulopenem, tebipenem, and amoxicillin exhibited moderate to low binding affinity. Durlobactam inactivated BlaMab and LDT/PBPs more potently than avibactam. The Ki,apps of durlobactam for PBP B, PBP-lipo, and LDT2 were below clinically achievable unbound concentrations, while avibactam's Ki,app for LDT/PBPs exceeded the clinical concentrations. Single β-lactam treatments resulted in minimal killing (~1 log10 reduction). Although avibactam yielded no effect, combinations with avibactam showed a significant reduction (~4 log10 CFU/mL). Durlobactam alone showed ~2 log10 reduction, and when combined with imipenem or two β-lactams, durlobactam achieved near-eradication of Mab, surpassing the current therapy (amikacin + clarithromycin + imipenem/cefoxitin). Inactivation of PBP-lipo by sulopenem, imipenem, durlobactam, and amoxicillin (with avibactam) led to morphological changes, showing filaments. This study demonstrates the mechanistic basis of combinations therapy, particularly imipenem + durlobactam, in overcoming β-lactam resistance in Mab.

Clinically significant hemoptysis and all-cause mortality in patients with nontuberculous mycobacterial pulmonary disease

BACKGROUND

Hemoptysis is one of the major symptoms in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD). However, its prevalence, incidence, and impact on long-term prognosis remain uncertain. We evaluated the incidence of clinically significant hemoptysis, and determined its association with mortality in patients with NTM-PD.

METHODS

Patients enrolled in a prospective observational cohort (NCT01616745) between July 2011 and May 2023 were analyzed. We evaluated risk factors for clinically significant hemoptysis-defined as hemoptysis events requiring interventions such as bronchial artery embolization or surgical resection-and its association with all-cause mortality.

RESULTS

Among 506 patients from the ongoing cohort, 43 patients (8.5 %) experienced clinically significant hemoptysis during a median follow-up of 5.1 years. The overall incidence of clinically significant hemoptysis was 2.1 (95 % confidence interval [CI]; 1.5-2.9) cases per 100 person-years. Identified risk factors included a history of tuberculosis (incidence rate ratio [IRR], 1.91; 95 % CI, 1.02-3.60), higher C-reactive protein (CRP) (IRR, 1.20 for 1 mg/dl increase; 95 % CI, 1.01-1.43), and lower % predicted forced vital capacity (FVC) (IRR, 0.81 for 10 % increase; 95 % CI, 0.66-0.98). Clinically significant hemoptysis was independently associated with an increased risk of all-cause mortality (adjusted hazard ratio, 2.39; 95 % CI, 1.31-4.36).

CONCLUSION

In patients with NTM-PD, those with history of tuberculosis, higher CRP levels, and lower % predicted FVC were at a higher risk of subsequent clinically significant hemoptysis. Importantly, clinically significant hemoptysis was associated with an elevated risk of all-cause mortality.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT01616745.

Predictive risk factors of treatment-refractory Mycobacterium avium complex lung disease: a single-center retrospective cohort study

Background

Mycobacterium avium complex lung disease (MAC-LD) is a chronic, progressive, potentially life-threatening infection. Some cases are refractory to standard guideline-based therapy (GBT), and sputum cultures are persistently positive for acid-fast bacilli. Although an early identification of treatment-refractory MAC-LD is crucial, its risk factors remain unknown.

Objectives

We aimed to identify the risk factors for refractory MAC-LD in response to initial GBT.

Design

A retrospective single-center study was conducted involving consecutive patients with MAC-LD who were diagnosed between 2006 and 2024 and received initial GBT.

Methods

Refractory MAC-LD was defined as sputum culture positivity at least 6 months after the initial GBT. Prognostic factors were identified using Cox proportional hazards analysis, and risk factors for refractory MAC-LD were examined using logistic regression analysis.

Results

Of the 201 patients with definite MAC-LD, 35 (17.4%) had refractory MAC-LD. Patients with refractory MAC-LD had a significantly lower body mass index (BMI), more cavitary lesions on high-resolution computed tomography (HRCT), and higher mortality (log-rank test, p = 0.006) compared to those with non-refractory MAC-LD. A multivariate analysis adjusted for age and sex showed that refractory MAC-LD (adjusted hazard ratio (HR): 2.76; 95% confidence interval (CI): 1.10-6.95; p = 0.030) and cavitary lesions on HRCT (adjusted HR: 2.77; 95% CI: 1.34-5.70; p = 0.005) were significantly associated with all-cause mortality. In addition, a multivariate analysis revealed that lower BMI (odds ratio (OR): 0.68; 95% CI: 0.55-0.85; p < 0.001) and cavitary lesions on HRCT (OR: 2.52; 95% CI: 1.15-5.50; p = 0.020) were independent risk factors of refractory MAC-LD.

Conclusion

Low BMI and cavitary lesions on HRCT are risk factors for refractory MAC-LD.

Risk Factors and Prognostic Effects of Aspergillosis as a Complication of Nontuberculous Mycobacterial Pulmonary Disease: A Nested Case-Control Study

OBJECTIVE

The global prevalence of nontuberculous mycobacterial pulmonary disease (NTM-PD) has been steadily increasing. A few small retrospective studies have reported a poor prognosis associated with chronic pulmonary aspergillosis (CPA) as a complication of NTM-PD. Furthermore, the prognostic impact of CPA may have been inadequately assessed due to differences in background factors. This study aimed to identify the risk factors for CPA in NTM-PD and compare the risk of in-hospital mortality between patients with and without aspergillosis.

METHODS

Data were obtained from a large-scale claims database. Patients with NTM-PD who met the inclusion criteria and those who developed CPA after the NTM diagnosis were identified. The incidence of CPA was evaluated, and risk factors were identified using multiple logistic analyses. Mortality rates were evaluated and compared between patients with and without aspergillosis after adjusting for background CPA risk factors.

RESULTS

The incidence of CPA was 2.29% (265/11,587). The identified risk factors included male sex, chronic respiratory failure, asthma, interstitial pneumonia, pulmonary tuberculosis sequelae and systemic corticosteroid use. A total of 219 patients with CPA were matched with control cases using propensity scores based on age and identified risk factors for CPA. The adjusted hazard ratio for in-hospital mortality was 2.6 (95% CI: 1.8-3.9).

CONCLUSIONS

CPA as a complication of NTM-PD is associated with significantly higher mortality rates. Clinicians should consider the necessity of promptly diagnosing CPA in patients with NTM-PD and the associated risk factors.

Clinical characteristics of pulmonary Mycobacterium avium complex disease in patients with interstitial lung disease

OBJECTIVE

Mycobacterium avium complex pulmonary disease (MAC-PD) is occasionally complicated by interstitial lung disease (ILD) in clinical practice, but clinical studies are limited. This study aims to elucidate the clinical and imaging characteristics of MAC-PD in patients with ILD.

METHODS

We retrospectively analyzed imaging and clinical data from medical records of 54 consecutive ILD patients diagnosed with MAC-PD from 2011 to 2021 at our institution. We compared the imaging and clinical data of these patients with 2218 ILD patients diagnosed at our institution.

RESULTS

The mean age of the patients was 74 years, with 25 males and 29 females, and a mean body mass index (BMI) of 20.0 kg/m2. Compared to all ILD patients, ILD-associated MAC-PD had older ages, lower BMI. The most common underlying ILD diagnosis was unclassifiable interstitial pneumonia. MAC-PD imaging classification was nodular-bronchiectatic (NB) type in 17 patients, fibro-cavitary (FC) type in 15 patients, and unclassifiable (UC) type in 22 patients. Many UC types were difficult to diagnose due to the absence of clear findings indicative of MAC infection. Chronic pulmonary aspergillosis complication was 24.1 %. The mean survival of ILD-associated MAC-PD was 55.6 months, shorter than that of regular MAC-PD. The UC type had a shorter survival than the NB type, similar to the FC type.

CONCLUSION

MAC-PD associated with ILD frequently complicates chronic pulmonary aspergillosis and has a poor prognosis. The most common imaging type, UC type, particularly has a shorter survival. Careful management is essential for MAC-PD associated with ILD.

Concurrent Coccidioidomycosis and Mycobacterium abscessus Infection in Chronic Obstructive Pulmonary Disease

Coccidioidomycosis, endemic in the southwestern United States, can lead to severe pulmonary complications, particularly in chronic obstructive pulmonary disease (COPD) patients with poor lung reserves. Mycobacterium abscessus has a predisposition for structurally damaged lungs, commonly causing difficult-to-treat bronchiectasis and cavitary lesions. We present the case of a 58-year-old patient with advanced COPD and a remote history of pulmonary coccidioidomycosis diagnosed 30 years earlier, who was found to have sputum and radiographic evidence of M. abscessus cavitary lung disease 4 years prior to admission, but was lost to follow-up. The current presentation is attributed to the progression of untreated M. abscessus infection and reactivation of latent Coccidioides infection. Despite the initiation of antifungal and antibiotic therapy, the subsequent course was complicated by the development of bronchopleural fistula and worsening respiratory failure, leading to an unfavorable outcome. This case highlights the diagnostic challenges associated with overlapping clinical and radiologic features of concurrent infections and devastating outcomes in patients with COPD. Prompt diagnostic testing and prolonged comprehensive therapy are of paramount importance in managing such complex infections.

A practical guide to the diagnosis and management of suspected Non-tuberculous Mycobacterial Pulmonary Disease (NTM-PD) in the United Kingdom

Non-tuberculous Mycobacterial Pulmonary Disease (NTM-PD) is a chronic disease characterised by progressive inflammatory lung damage due to infection by non-tuberculous mycobacteria (NTM). Global prevalence of NTM-PD is generally low but is rising, likely due to a combination of increased surveillance, increasing multimorbidity and improved diagnostic techniques. Most disease is caused by Mycobacterium avium complex species. NTM-PD can be challenging to both diagnose and manage but given the risk of untreated disease and the challenges around drug treatments, it is vital that all healthcare professionals involved in primary care consider NTM-PD at the earliest opportunity. In particular, NTM-PD should be considered where there are respiratory symptoms in the setting of pre-existing chronic lung disease such as chronic obstructive pulmonary disease (COPD) and bronchiectasis. Early suspicion should lead to appropriate primary screening measures. This article discusses the relevance of NTM-PD today, risk factors for developing disease, pathways from clinical presentation to referral to specialist care, and discusses management and drug treatments. A flow diagram of a screening process is presented as a guideline for best practice from a United Kingdom perspective.

Toward better cures for Mycobacterium abscessus lung disease

SUMMARYThe opportunistic pathogen Mycobacterium abscessus (Mab) causes fatal lung infections that bear similarities-and notable differences-with tuberculosis (TB) pulmonary disease. In contrast to TB, no antibiotic is formally approved to treat Mab disease, there is no reliable cure, and the discovery and development pipeline is incredibly thin. Here, we discuss the factors behind the unsatisfactory cure rates of Mab disease, namely intrinsic resistance and persistence of the pathogen, and the use of underperforming, often parenteral and toxic, repurposed drugs. We propose preclinical strategies to build injectable-free sterilizing and safe regimens: (i) prioritize oral bactericidal antibiotic classes, with an initial focus on approved agents or advanced clinical candidates to provide immediate options for desperate patients, (ii) test drug combinations early, (iii) optimize novel leads specifically for M. abscessus, and (iv) consider pharmacokinetic-pharmacodynamic targets at the site of disease, the lung lesions in which drug tolerant bacterial populations reside. Knowledge and tool gaps in the preclinical drug discovery process are identified, including validated mouse models and computational platforms to enable in vitro mouse-human translation. We briefly discuss recent advances in clinical development, the need for readouts and biomarkers that correlate with cure, and clinical trial concepts adapted to the uniqueness of Mab patient populations for new regimen development. In an era when most pharmaceutical firms have withdrawn from antimicrobial drug discovery, the breakthroughs needed to fill the regimen development pipeline will likely come from partnerships between academia, biotech, pharma, non-profit organizations, and governments, with incentives that reward cooperation.

Multidrug tolerance conferred by loss-of-function mutations in anti-sigma factor RshA of Mycobacterium abscessus

Low-level drug resistance in noncanonical pathways can constitute steppingstones toward acquisition of high-level on-target resistance mutations in the clinic. To capture these intermediate steps in Mycobacterium abscessus (Mab), we performed classic mutant selection experiments with moxifloxacin at twofold its minimum inhibitory concentration (MIC) on solid medium. We found that low-level resistance emerged reproducibly as loss-of-function mutations in RshA (MAB_3542c), an anti-sigma factor that negatively regulates activity of SigH, which orchestrates a response to oxidative stress in mycobacteria. Since oxidative stress is generated in response to many antibiotics, we went on to show that deletion of rshA confers low to moderate resistance-by measure of MIC-to a dozen agents recommended or evaluated for the treatment of Mab pulmonary infections. Interestingly, this moderate resistance was associated with a wide range of drug tolerance, up to 1,000-fold increased survival of a ΔrshA Mab mutant upon exposure to several β-lactams and DNA gyrase inhibitors. Consistent with the putative involvement of the SigH regulon, we showed that addition of the transcription inhibitor rifabutin (RBT) abrogated the high-tolerance phenotype of ΔrshA to representatives of the β-lactam and DNA gyrase inhibitor classes. In a survey of 10,000 whole Mab genome sequences, we identified several loss-of-function mutations in rshA as well as non-synonymous polymorphisms in two cysteine residues critical for interactions with SigH. Thus, the multidrug multiform resistance phenotype we have uncovered may not only constitute a step toward canonical resistance acquisition during treatment but also contribute directly to treatment failure.

Long-term clinical course of Mycobacterium avium complex pulmonary disease patients with treatment failure

Despite guideline-based therapy, some patients with Mycobacterium avium complex pulmonary disease (MAC-PD) experience treatment failure. We analyzed the clinical courses of 271 patients with treatment-refractory MAC-PD who discontinued therapy after at least 12 months. Patients were categorized into two groups-the retreatment group, who resumed antibiotics due to clinical or radiological deterioration, and the stable group, who did not require antibiotics. Of the study patients, 138 (51%) were in the retreatment group, whereas 133 (49%) were in the stable group. In the multivariate analysis models, an elevated erythrocyte sedimentation rate (adjusted hazard ratio [aHR] =1.01), the presence of a cavity (aHR = 1.75), and the number of lobes affected by bronchiectasis (aHR = 1.21) were associated with the need for retreatment. Our data indicated that approximately 50% of the patients with refractory MAC-PD who discontinued antibiotics eventually required retreatment, which was influenced by the extent of lung destruction or inflammation. These findings can aid in determining treatment strategies for patients with refractory diseases.

Nontuberculous Mycobacterial Infective Endocarditis: A Systematic Review of Clinical Characteristics and Outcomes

Background

Infective endocarditis (IE) due to nontuberculous mycobacteria (NTM) is a rare infection, and several outbreaks have been reported in the last 2 decades. However, the clinical spectrum is still poorly understood. This systematic review aimed to evaluate the clinical characteristics and outcomes in NTM IE.

Methods

We searched the major electronic databases (PubMed, Scopus, and Google Scholar) with appropriate keywords to December 2023. We included studies based on predefined diagnostic criteria, and relevant data were collected on clinical presentation and treatment outcomes. The study was registered with PROSPERO (CRD42023492577).

Results

A total of 97 studies were reviewed, encompassing 167 patients with NTM IE. The earliest cases were reported in 1975, involving M chelonae and M fortuitum. M chimaera was the most prevalent species (38.9%), though rapidly growing NTM (RGM) were more common than slow-growing NTM (SGM; 59.3% vs 40.7%). Disseminated NTM infection occurred in 84% of cases, with bone marrow infiltration and osteomyelitis as frequent manifestations. Prosthetic valves were the main risk factor, present in 63.5% of cases. In native valve IE, nearly all cases (n = 27, 96%) were attributed to RGM. The overall mortality rate was 44.9%, with conservative management without surgery associated with poorer outcomes (66.7% vs 30.6%). Mortality was comparable between SGM and RGM IE, although relapses were more common in SGM IE (17.6% vs 1.9%).

Conclusions

This review highlights the changing epidemiology of NTM IE with the emergence of RGM IE. Disseminated infections in the setting of prosthetic valves warrant NTM evaluation. The high mortality rate necessitates the role of early surgery.

Utility of 18F-Fluorodeoxyglucose Positron Emission Tomography in Evaluating Disseminated Nontuberculous Mycobacterial Infection in Patients With Anti-interferon-γ Autoantibodies

Background

Managing disseminated nontuberculous mycobacterial (NTM) infection in patients with neutralizing anti-interferon-γ autoantibodies (AIGAs) poses substantial challenges due to the lack of established treatment guidance and predictive tools for clinical outcomes. In this study, we investigated the utility of 18F-fluorodeoxyglucose (2-[18F]FDG) positron emission tomography (PET) in guiding treatment decisions, with a focus on its ability to predict rehospitalization outcomes.

Methods

We conducted a post hoc analysis of the first available 2-[18F]FDG PET scans of patients with AIGAs and disseminated NTM infection from a prospective observational multicenter cohort. Cox proportional hazards regression was used to determine predictors for disease-related rehospitalization within 1 year of the examination.

Results

Of the patients with AIGAs evaluated, 41.9% required rehospitalization within 1 year following the initial 2-[18F]FDG PET evaluation. Slowly growing mycobacteria were isolated in 64.5% of patients. Multivariable analysis identified splenic involvement (adjusted hazard ratio, 7.97; 95% CI, 2.34-27.16; P < .001) as a significant predictor of disease-related rehospitalization within 1 year following the examination. Moreover, mediastinal node involvement (adjusted odds ratio, 14.77; 95% CI, 1.01-216.76; P = .049) and axial skeleton involvement (adjusted odds ratio, 14.93; 95% CI, 1.11-201.43; P = .042) were significantly associated with the isolation of slowly growing mycobacteria.

Conclusions

2-[18F]FDG PET appears useful in initial evaluation of disease extent and microbiology in patients with AIGAs and disseminated NTM infection. Identifying splenic involvement through this modality may help recognize patients at increased risk of disease-related rehospitalization within 1 year. These findings suggest that 2-[18F]FDG PET could inform management decisions in this challenging population.

Non-Tuberculous Mycobacteria: Single Center Analyses of Risk Factors, Management and Mortality Outcomes of Adults with HIV

BACKGROUND/OBJECTIVES

In sub-Saharan Africa, there is paucity of data regarding non-tuberculous mycobacterial (NTM) infections, leading to underappreciation of disease burden. Consequently, fewer resources are allocated, leading to potential adverse outcomes. This study examines long-term mortality and risk factors of South African patients with positive NTM samples.

METHODS

We conducted a retrospective analysis of clinical isolates of NTMs between 1 January 2010 and 30 June 2017. We retrieved and thoroughly reviewed the corresponding medical records of patients treated at Charlotte Maxeke Johannesburg Academic Hospital. Outcomes were compared between patients who underwent different therapy regimens, including macrolide-based regimens and 'watchful waiting'.

RESULTS

A total of 123 patients were followed for a median of 1 year (interquartile range [IQR], 0.5-4.5). The median age was 39 years (IQR, 31-51) with male predominance, 58%. The common comorbid conditions were HIV (encountered in 78%) and previous TB (58%). Pulmonary disease due to Mycobacterium avium complex (MAC-PD) was found in 74% of patients, M. fortiutum in 5%, and M. gordonae in 4%. The mortality relative risk for patients on initial macrolide-containing therapy was 0.54 (95% confidence interval [CI], 0.22-1.36), p = 0.194, while that for macrolide-free antimicrobials was 1.38 (95% CI, 0.57-3.34), p = 0.471. The adjusted hazard rate for mortality with low CD4 counts < 50 cells/mm3 was 2.79 (95%, 1.20-6.50), while that for unknown CD4 counts was 4.01 (95% CI, 1.17-13.77), compared to CD4 counts > 50 cells/mm3.

CONCLUSIONS

Among HIV patients, NTM-PD predominated, and not disseminated disease. MAC-PD was the most common infection. Low CD4 counts was a significant risk factor for early death, while sex, NTM species, macrolide therapy, and previous TB were not.

Nontuberculous Mycobacterial Pulmonary Disease: Patients, Principles, and Prospects

Nontuberculous mycobacterial pulmonary disease (NTM-PD) is increasing in incidence globally and challenging to manage. The 2020 multisociety treatment guideline and the 2022 consensus recommendations provide comprehensive evidence-based guides to manage pulmonary diseases caused by the most common NTM. However, with >190 different NTM species that may require different multidrug regimens for treatment, the breadth and complexity of NTM-PD remain daunting for both patients and clinicians. In this narrative review, we aim to distill this broad, complex field into principles applicable to most NTM species and highlight important nuances, specifically elaborating on the presentation, diagnosis, principles of patient-centered care, principles of pathogen-directed therapy, and prospects of NTM-PD.

Significance of changes in cavity after treatment in Mycobacterium avium complex pulmonary disease

Cavities are characteristic radiological features related to increased mycobacterial burden and poor prognosis in Mycobacterium avium complex pulmonary disease (MAC-PD). However, cavity changes following treatment and their clinical implications remain unknown. We aimed to elucidate whether cavity obliteration or reduction in cavity size or wall thickness correlates with microbiological cure. In total, 136 adult patients with cavitary MAC-PD treated for ≥ 6 months between January 1st, 2009, and December 31st, 2021, in a tertiary referral centre in South Korea were enrolled. The cavity with the largest diameter at treatment initiation was tracked for size and thickness changes. Following median treatment of 20.0 months, 74 (54.4%) patients achieved microbiological cure. Cavity obliteration, achieved in 58 (42.6%) patients at treatment completion, was independently associated with microbiological cure. In patients with persistent cavities, size reduction of ≥ 10% was significantly associated with microbiological cure, whereas thickness reduction was not. Five-year mortality rates in patients with cavity obliteration, persistent but reduced cavity, and persistent cavity without shrinkage were 95.6%, 72.1%, and 65.3%, respectively (P < 0.001). In conclusion, cavity obliteration or shrinkage at treatment completion is associated with microbiological cure and reduced mortality in MAC-PD, suggesting that cavity changes could serve as a proxy indicator for treatment response.

The Association Between Sputum Culture Conversion and Mortality in Cavitary Mycobacterium avium Complex Pulmonary Disease

BACKGROUND

The association between treatment outcome and the mortality of patients with Mycobacterium avium complex pulmonary disease (MAC-PD) with cavitary lesions is unclear. This article assessed the impact of culture conversion on mortality in patients with cavitary MAC-PD.

RESEARCH QUESTION

Is the achievement of sputum culture conversion in patients with MAC-PD with cavitary lesions associated with the prognosis?

STUDY DESIGN AND METHODS

From 2002 to 2020, a total of 351 patients with cavitary MAC-PD (105 with the fibrocavitary type and 246 with the cavitary nodular bronchiectatic type), who had been treated with a ≥ 6-month macrolide-containing regimen at a tertiary referral center in South Korea, were retrospectively enrolled in this study. All-cause mortality during the follow-up period was analyzed based on culture conversion at the time of treatment completion.

RESULTS

The cohort had a median treatment duration of 14.7 months (interquartile range [IQR], 13.4-16.8 months). Of the 351 patients, 69.8% (245 of 351) achieved culture conversion, and 30.2% (106 of 351) did not. The median follow-up was 4.4 years (IQR, 2.3-8.3 years) in patients with culture conversion and 3.1 years (IQR, 2.1-4.8 years) in those without. For the patients with and without culture conversion, all-cause mortality was 5.3% vs 35.8% (P < .001), and the 5-year cumulative mortality was 20.0% vs 38.4%, respectively. Cox analysis found that a lack of culture conversion was significantly associated with higher mortality (adjusted hazard ratio, 5.73; 95% CI, 2.86-11.50). Moreover, the 2-year landmark analysis revealed a distinct impact of treatment outcome on mortality.

INTERPRETATION

The mortality rate of patients with cavitary MAC-PD who did not achieve culture conversion was significantly higher than that of those with culture conversion.

Patients at risk of nontuberculous mycobacterial pulmonary disease who need testing evaluated using a modified Delphi process by European experts

Background

Identifying patients at risk of nontuberculous mycobacterial pulmonary disease (NTM-PD) is challenging. Delays in NTM-PD identification and management are associated with declining lung function and increased morbidity and mortality.

Study design and methods

European NTM-PD experts (n=12) participated in a three-round modified Delphi process to score symptoms and comorbidities potentially associated with NTM-PD as reasons to test for nontuberculous mycobacteria.

Results

Experts reached a consensus on the symptoms and comorbidities that should and should not prompt testing for nontuberculous mycobacteria. Requirements for testing were scored as high (mean ≥7), medium (mean ≥4-<7) or low (mean <4). Nontuberculous mycobacteria testing should be undertaken when multiple suggestive symptoms are present simultaneously in all patients except those with cancer (7.3-8.8), or when radiology is indicative of NTM-PD (≥8.9). Symptoms of persistent sputum production, recurrent respiratory infection and haemoptysis should prompt testing for nontuberculous mycobacteria, particularly in those with underlying respiratory diseases. Symptomatic patients with bronchiectasis or previous tuberculosis/NTM-PD or those being prescribed or undergoing long-term macrolide therapy for a respiratory condition should also be tested. Testing is not warranted in patients without an underlying respiratory disorder or in those without a history of respiratory disorders unless presenting with multiple symptoms.

Conclusions

Assessing patients' risk of NTM-PD is challenging. This Delphi consensus process provides insight into symptoms and clinical characteristics that should prompt NTM-PD assessment. Timely testing and diagnosis would enable initiation of appropriate management.

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 one-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.

Supporting Patients with Nontuberculous Mycobacterial Pulmonary Disease: Ensuring Best Practice in UK Healthcare Settings

Nontuberculous mycobacterial pulmonary disease (NTM-PD) results from opportunistic lung infections by mycobacteria other than Mycobacterium tuberculosis or Mycobacterium leprae species. Similar to many other countries, the incidence of NTM-PD in the United Kingdom (UK) is on the rise for reasons that are yet to be determined. Despite guidelines established by the American Thoracic Society (ATS), the Infectious Diseases Society of America, and the British Thoracic Society, NTM-PD diagnosis and management remain a significant clinical challenge. In this review article, we comprehensively discuss key challenges in NTM-PD diagnosis and management, focusing on the UK healthcare setting. We also propose countermeasures to overcome these challenges and improve the detection and treatment of patients with NTM-PD.

Single-cell transcriptomics by clinical course of Mycobacterium avium complex pulmonary disease

Mycobacterium avium complex pulmonary disease (MAC-PD) has a heterogeneous clinical course. However, immune profiles associated with MAC-PD clinical course are limited. We performed single-cell RNA sequencing of peripheral blood mononuclear cells from 21 MAC-PD patients divided into three clinical courses: group A, spontaneous culture conversion; group B, stable disease without antibiotic treatment; and group C, progressive disease with antibiotic treatment. A lower proportion of NK cells and higher proportion of monocytes were noted in group C compared to combined groups A and B. The proportion of classical monocytes was higher in group C compared to groups A and B, while the proportion of non-classical monocytes decreased. EGR1, HSPA1A, HSPA1B, and CD83 were up-regulated in spontaneous culture conversion group A compared to progressive disease group C. Up-regulation of MYOM2 and LILRA4 and down-regulation of MT-ATP8, CD83, and CCL3L1 was found in progressive disease group C. PCBP1, FOS, RGCC, S100B, G0S2, AREG, and LYN were highly expressed in favorable treatment response compared to unfavorable response. Our findings may offer a comprehensive understanding of the host immune profiles that influence a particular MAC-PD clinical course and could suggest an immunological mechanism associated with the disease progression of MAC-PD.

Epidemiological Characteristics of Nontuberculous Mycobacterial Pulmonary Disease in South Korea: A Meta-analysis of Individual Participant Data

BACKGROUND

Despite the global increase in nontuberculous mycobacterial pulmonary disease (NTM-PD), clinical characteristics show geographical variations. We investigated the clinical characteristics of patients with NTM-PD in South Korea.

METHODS

We systematically reviewed articles concerning patients with NTM-PD in South Korea until February 2022. Individual participant data, regardless of treatment, were collected using a standard case report form.

RESULTS

Data of 6,489 patients from 11 hospitals between 2002 and 2019 were analyzed. The mean age was 61.5±11.7 years, of whom 57.7% were women. Mycobacterium avium (41.4%) and Mycobacterium intracellulare (38.4%) comprised most of the causative species, followed by Mycobacterium abscessus subspecies abscessus (8.6%) and M. abscessus subspecies massiliense (7.8%). Bronchiectasis (59.4%) was the most common pulmonary comorbidity. Although reported cases of NTM-PD increased over the years, the proportions of causative species and radiologic forms remained similar. Distinct clinical characteristics were observed according to age and sex. Men were older at the time of diagnosis (median 63.8 years vs. 59.9 years, p<0.001), and had more cavitary lesions than women (38.8% vs. 21.0%, p<0.001). The older group (≥65 years) had higher proportions of patients with body mass index <18.5 kg/m2 (27.4% vs. 18.6%, p<0.001) and cavitary lesions (29.9% vs. 27.6%, p=0.009) than the younger group.

CONCLUSION

We conducted a meta-analysis of the clinical characteristics of patients with NTM-PD in South Korea, and found age- and sex-related differences in disease- specific severity. Further investigation would enhance our comprehension of the nature of the disease, and inherited and acquired host factors.

The Impact of Trehalose Dimycolate on the Clinical Course of Mycobacterium avium Complex Pulmonary Disease

Rationale: The clinical implications of trehalose 6,6'-dimycolate (TDM) in nontuberculous mycobacterial pulmonary disease have not been studied. Objectives: To examine the presence of TDM in clinical isolates obtained from patients with Mycobacterium avium complex (MAC) pulmonary disease (PD) and its impact on disease severity and treatment outcomes. Methods: We analyzed clinical isolates from patients with diagnoses of MAC PD at Seoul National University Hospital between January 1, 2019, and December 31, 2021. The lipids were extracted from clinical isolates obtained at the time of diagnosis using mass spectrometry. Mass peaks between 300 and 3,500 m/z were obtained, and the peak patterns of the total lipids were analyzed. Results: TDM was identified in clinical isolates from 176 of 343 patients. Cavities were more prevalent in patients with TDM-negative isolates (19.8%) than in those with TDM-positive isolates (10.2%) (P = 0.015). The time to antibiotic treatment was shorter in patients with TDM-negative isolates (4 mo [interquartile range, 2-10 mo]) than in those with TDM-positive isolates (7 mo [interquartile range, 3-16 mo]) (P = 0.032). Patients with TDM-negative isolates had a significantly lower proportion of culture conversions (P = 0.012). TDM was associated with higher likelihood of culture conversion (adjusted hazard ratio, 2.29; P = 0.035). Conclusions: TDM-negative isolates were linked to a higher occurrence of cavities, earlier initiation of treatment, and worse treatment outcome in patients with MAC PD.

Five-Year Outcomes among U.S. Bronchiectasis and NTM Research Registry Patients

Rationale: Nontuberculous mycobacteria (NTM) are prevalent among patients with bronchiectasis. However, the long-term natural history of patients with NTM and bronchiectasis is not well described. Objectives: To assess the impact of NTM on 5-year clinical outcomes and mortality in patients with bronchiectasis. Methods: Patients in the Bronchiectasis and NTM Research Registry with ⩾5 years of follow-up were eligible. Data were collected for all-cause mortality, lung function, exacerbations, hospitalizations, and disease severity. Outcomes were compared between patients with and without NTM at baseline. Mortality was assessed using Cox proportional hazards models and the log-rank test. Measurements and Main Results: In total, 2,634 patients were included: 1,549 (58.8%) with and 1,085 (41.2%) without NTM at baseline. All-cause mortality (95% confidence interval) at Year 5 was 12.1% (10.5%, 13.7%) overall, 12.6% (10.5%, 14.8%) in patients with NTM, and 11.5% (9.0%, 13.9%) in patients without NTM. Independent predictors of 5-year mortality were baseline FEV1 percent predicted, age, hospitalization within 2 years before baseline, body mass index, and sex (all P < 0.01). The probabilities of acquiring NTM or Pseudomonas aeruginosa were approximately 4% and 3% per year, respectively. Spirometry, exacerbations, and hospitalizations were similar, regardless of NTM status, except that annual exacerbations were lower in patients with NTM (P < 0.05). Conclusions: Outcomes, including exacerbations, hospitalizations, rate of loss of lung function, and mortality rate, were similar across 5 years in patients with bronchiectasis with or without NTM.

Usefulness of the mini nutritional assessment short-form for evaluating nutritional status in patients with nontuberculous mycobacterial pulmonary disease: a prospective cross-sectional study

BACKGROUND

Although the Mini Nutritional Assessment (MNA) is recognized as a useful tool for evaluating nutritional status in patients with various diseases, its applicability in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) remains undetermined.

METHODS

We designed a prospective cross-sectional study to investigate whether the MNA Short-Form (MNA-SF) score can serve as a screening tool to assess the nutritional status of patients with NTM-PD. The MNA-SF was conducted upon patient enrollment, and correlation analyses were performed to compare MNA-SF scores with other nutritional measurements and disease severity. Multivariable logistic regression analyses were conducted to evaluate the association between MNA-SF scores and NTM-PD severity.

RESULTS

The 194 patients with NTM-PD included in the analysis had a median age of 65.0 (59.0-69.0) years; 59.3% (n = 115) had low MNA-SF scores (< 12). The low MNA-SF group exhibited a lower body mass index (19.7 vs. 22.4 kg/m2, p < 0.001) and fat-free mass index (14.7 vs. 15.6 kg/m2, p < 0.001) than the normal MNA-SF group, as well as higher incidences of sarcopenia (20.0% vs. 6.3%, p = 0.008) and adipopenia (35.7% vs. 5.1%, p < 0.001). However, no significant differences in calorie and protein intakes were observed between the two groups. Low MNA-SF scores were associated with radiographic severity (adjusted odds ratio 2.72, 95% confidence interval 1.38-5.36) but not with forced vital capacity.

CONCLUSIONS

The MNA-SF can effectively assess the nutritional status of patients with NTM-PD and can serve as an important clinical indicator in NTM-PD where treatment timing is determined by clinical judgment.

Improvement in Health-Related Quality of Life Following Antibiotic Treatment in Nontuberculous Mycobacterial Pulmonary Disease: Initial Analysis of the NTM-KOREA Cohort

BACKGROUND

Improving health-related quality of life (HRQOL) has emerged as a priority in the management of nontuberculous mycobacterial pulmonary disease (NTM-PD). We aimed to evaluate HRQOL and its changes after 6 months' treatment in patients with NTM-PD.

METHODS

The NTM-KOREA is a nationwide prospective cohort enrolling patients initiating treatment for NTM-PD in 8 institutions across South Korea. We conducted the Quality of Life-Bronchiectasis (QOL-B) at 6-month intervals and evaluated baseline scores (higher scores indicate better quality of life) and changes after 6 months' treatment. Multivariate logistic regression was performed to identify factors associated with improvement in the QOL-B physical functioning and respiratory symptoms domains.

RESULTS

Between February 2022 and August 2023, 411 patients were included in the analysis. Baseline scores (95% confidence interval [CI]) for physical functioning and respiratory symptoms were 66.7 (46.7-86.7) and 81.5 (70.4-92.6), respectively. Among 228 patients who completed the QOL-B after 6 months' treatment, improvements in physical functioning and respiratory symptoms were observed in 61 (26.8%) and 71 (31.1%) patients, respectively. A lower score (adjusted odds ratio; 95% CI) for physical functioning (0.93; 0.91-0.96) and respiratory symptoms (0.92; 0.89-0.95) at treatment initiation was associated with a greater likelihood of physical functioning and respiratory symptom improvement, respectively; achieving culture conversion was not associated with improvement in physical functioning (0.62; 0.28-1.39) or respiratory symptoms (1.30; 0.62-2.74).

CONCLUSIONS

After 6 months of antibiotic treatment for NTM-PD, HRQOL improved in almost one-third, especially in patients with severe initial symptoms, regardless of culture conversion.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov identifier: NCT03934034.

Detection of Mtb and NTM: preclinical validation of a new asymmetric PCR-binary deoxyribozyme sensor assay

Tuberculosis (TB) and infectious diseases caused by non-tuberculous mycobacteria (NTM) are global concerns. The development of a rapid and accurate diagnostic method, capable of detecting and identifying different mycobacteria species, is crucial. We propose a molecular approach, the BiDz-TB/NTM, based on the use of binary deoxyribozyme (BiDz) sensors for the detection of Mycobacterium tuberculosis (Mtb) and NTM of clinical interest. A panel of DNA samples was used to evaluate Mtb-BiDz, Mycobacterium abscessus/Mycobacterium chelonae-BiDz, Mycobacterium avium-BiDz, Mycobacterium intracellulare/Mycobacterium chimaera-BiDz, and Mycobacterium kansasii-BiDz sensors in terms of specificity, sensitivity, accuracy, and limit of detection. The BiDz sensors were designed to hybridize specifically with the genetic signatures of the target species. To obtain the BiDz sensor targets, amplification of a fragment containing the hypervariable region 2 of the 16S rRNA was performed, under asymmetric PCR conditions using the reverse primer designed based on linear-after-the-exponential principles. The BiDz-TB/NTM was able to correctly identify 99.6% of the samples, with 100% sensitivity and 0.99 accuracy. The individual values of specificity, sensitivity, and accuracy, obtained for each BiDz sensor, satisfied the recommendations for new diagnostic methods, with sensitivity of 100%, specificity and accuracy ranging from 98% to 100% and from 0.98 to 1.0, respectively. The limit of detection of BiDz sensors ranged from 12 genome copies (Mtb-BiDz) to 2,110 genome copies (Mkan-BiDz). The BiDz-TB/NTM platform would be able to generate results rapidly, allowing the implementation of the appropriate therapeutic regimen and, consequently, the reduction of morbidity and mortality of patients.IMPORTANCEThis article describes the development and evaluation of a new molecular platform for accurate, sensitive, and specific detection and identification of Mycobacterium tuberculosis and other mycobacteria of clinical importance. Based on BiDz sensor technology, this assay prototype is amenable to implementation at the point of care. Our data demonstrate the feasibility of combining the species specificity of BiDz sensors with the sensitivity afforded by asymmetric PCR amplification of target sequences. Preclinical validation of this assay on a large panel of clinical samples supports the further development of this diagnostic tool for the molecular detection of pathogenic mycobacteria.

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.

Therapeutic developments for tuberculosis and nontuberculous mycobacterial lung disease

Tuberculosis (TB) drug discovery and development has undergone nothing short of a revolution over the past 20 years. Successful public-private partnerships and sustained funding have delivered a much-improved understanding of mycobacterial disease biology and pharmacology and a healthy pipeline that can tolerate inevitable attrition. Preclinical and clinical development has evolved from decade-old concepts to adaptive designs that permit rapid evaluation of regimens that might greatly shorten treatment duration over the next decade. But the past 20 years also saw the rise of a fatal and difficult-to-cure lung disease caused by nontuberculous mycobacteria (NTM), for which the drug development pipeline is nearly empty. Here, we discuss the similarities and differences between TB and NTM lung diseases, compare the preclinical and clinical advances, and identify major knowledge gaps and areas of cross-fertilization. We argue that applying paradigms and networks that have proved successful for TB, from basic research to clinical trials, will help to populate the pipeline and accelerate curative regimen development for NTM disease.

Clinical course of nontuberculous mycobacterial pulmonary disease in patients with rheumatoid arthritis

OBJECTIVES

The impact of rheumatoid arthritis (RA) on nontuberculous mycobacterial pulmonary disease (NTM-PD) has not been well established. In this study, we investigated the clinical course of NTM-PD in patients with RA and the impact of RA on the prognosis of NTM-PD.

METHODS

We analyzed patients who developed NTM-PD after being diagnosed with RA from January 2004 to August 2023 at a tertiary referral hospital in South Korea. The patient's baseline characteristics, clinical course, and prognosis were evaluated. An optimal matching analysis was performed to measure the impact of RA on the risk of mortality.

RESULTS

During the study period, 18 patients with RA [median age, 68 years; interquartile range (IQR) 59-73; female, 88.9%] developed NTM-PD. The median interval between RA diagnosis and subsequent NTM-PD development was 14.8 years (IQR, 8.6-19.5). At a median of 30 months (IQR, 27-105) after NTM-PD diagnosis, 10 of 18 (55.6%) patients received anti-mycobacterial treatment for NTM-PD and 5 (50.0%) patients achieved microbiological cure. When matched to patients with NTM-PD but without RA, patients with both RA and NTM-PD had a higher risk of mortality (adjusted hazard ratio, 8.14; 95% confidence interval, 2.43-27.2).

CONCLUSION

NTM-PD occurring after RA is associated with a higher risk of mortality than NTM-PD in the absence of RA.

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.

Treatment Outcomes of Clofazimine-Containing Regimens in Severe Mycobacterium avium Complex Pulmonary Disease

Background

Clofazimine is suggested as a promising drug for the treatment of nontuberculous mycobacterial pulmonary disease. However, the role of clofazimine in severe Mycobacterium avium complex pulmonary disease (MAC-PD) remains unclear. In this study, we investigated the treatment outcomes of patients with severe MAC-PD treated with regimens containing clofazimine.

Methods

This study included patients diagnosed with severe MAC-PD at Seoul National University Hospital who underwent anti-mycobacterial treatment between 1 January 2011 and 31 December 2022. We assessed the rate of culture conversion within 6 months and microbiological cure in patients receiving clofazimine-containing regimens, considering the dose and duration of clofazimine administration.

Results

A total of 170 patients with severe MAC-PD, treated with regimens containing clofazimine, were included in the analysis. The median age of patients was 68 years (interquartile range, 59-75 years), with a female predominance (n = 114 [67.1%]). Cavities were identified in 121 patients (71.2%). Within 6 months, 77 patients (45.3%) achieved culture conversion, and 84 of 154 (54.6%) patients attained microbiological cure. The dose of clofazimine (100 mg vs 50 mg) was not associated with culture conversion (adjusted odds ratio [aOR], 0.64 [95% confidence interval {CI}, .29-1.42]) or microbiological cure (aOR, 1.21 [95% CI, .52-2.81]). The microbiological cure rate reached 71.0% when clofazimine was administered for 6-12 months, compared to 23.1% when administered for <6 months.

Conclusions

Clofazimine demonstrated a relatively favorable efficacy in severe MAC-PD, regardless of the maintenance dose. This effect was more pronounced when administered for a duration exceeding 6 months.

Post-treatment Radiographic Severity and Mortality in Mycobacterium avium Complex Pulmonary Disease

Rationale: Imaging studies are widely performed when treating Mycobacterium avium complex pulmonary disease (MAC-PD); however, the clinical significance of post-treatment radiographic change is unknown. Objectives: To determine whether a deep neural network trained with pulmonary tuberculosis could adequately score the radiographic severity of MAC-PD and then to examine relationships between post-treatment radiographic severity and its change from baseline and long-term prognosis. Methods: We retrospectively collected chest radiographs of adult patients with MAC-PD treated for ⩾6 months at baseline and at 3, 6, 9, and 12 months of treatment. We correlated the radiographic severity score generated by a deep neural network with visual and clinical severity as determined by radiologists and mycobacterial culture status, respectively. The associations between the score, improvement from baseline, and mortality were analyzed using Cox proportional hazards regression. Results: In total, 342 and 120 patients were included in the derivation and validation cohorts, respectively. The network's severity score correlated with radiologists' grading (Spearman coefficient, 0.40) and mycobacterial culture results (odds ratio, 1.02; 95% confidence interval [CI], 1.0-1.05). A significant decreasing trend in the severity score was observed over time (P < 0.001). A higher score at 12 months of treatment was independently associated with higher mortality (adjusted hazard ratio, 1.07; 95% CI, 1.03-1.10). Improvements in radiographic scores from baseline were associated with reduced mortality, regardless of culture conversion (adjusted hazard ratio, 0.42; 95% CI, 0.22-0.80). These findings were replicated in the validation cohort. Conclusions: Post-treatment radiographic severity and improvement from baseline in patients with MAC-PD were associated with long-term survival.

The role of treatment regimen and duration in treating patients with Mycobacterium avium complex lung disease: A real-world experience and case-control study

PURPOSE

The treatment advantage of guideline-based therapy (GBT) in Mycobacterium avium complex lung disease (MAC-LD) is well-known. However, GBT is not always feasible. The aim of the study was to analyze the relationship of treatment regimens and duration with outcomes.

MATERIALS AND METHODS

This study screened patients with MAC-LD from Jan 2011 to Dec 2020 and enrolled those who received treatment. The treatment regimens were categorized to triple therapy (three active drugs) and non-triple therapy. The favorable outcomes included microbiological cure or clinical cure if no microbiologic persistence.

RESULTS

A total of 106 patients with MAC-LD were enrolled. Among them, 88 subjects (83 %) received triple therapy, 58 (54.7 %) had MAC treatment >12 months, and 66 (62.3 %) had favorable outcomes. Patients receiving triple therapy (90.9 % vs. 67.5 %, p = 0.008) and treatment >12 months (62.1 % vs. 42.5 %, p = 0.07) had higher proportion of favorable outcomes than unfavorable outcomes. Multivariable logistic regression analysis showed that age >65, comorbidities of COPD and prior tuberculosis, low hemoglobin, and high MAC burden were independent risk factors of unfavorable outcome. In contrast, triple therapy (OR: 0.018, 95 % CI: 0.04-0.78, p = 0.022) and treatment duration >12 months (OR: 0.20, 95 % CI: 0.055-0.69, p = 0.012) were protective factors against unfavorable outcome.

CONCLUSIONS

Triple therapy including GBT, and treatment more than 12 months achieved more favorable outcome. Maintenance of triple therapy, but not reducing the number of active drugs, might be an acceptable alternative of GBT.

Chronic Pulmonary Aspergillosis: Clinical Presentation and Management

Chronic pulmonary aspergillosis (CPA) refers to a number of clinical syndromes resulting from the presence and local proliferation of Aspergillus organisms in the lungs of patients with chronic lung disease. CPA is more common than was realized two decades ago. Recognition remains poor, despite recent studies from many countries highlighting the high prevalence in at-risk populations. In low- and middle-income countries, CPA may be misdiagnosed and treated as tuberculosis (TB). In addition, CPA may develop following successful TB treatment. The coronavirus disease pandemic has resulted in significant disruption to provision of TB care, likely leading to more extensive lung damage, which could increase the risk for CPA.Although CPA refers to various syndromes, the classic presentation is that of chronic cavitary pulmonary aspergillosis, which manifests as one or more progressive cavities with or without a fungal ball, accompanied by systemic and respiratory symptoms for at least 3 months. Diagnosis relies on Aspergillus immunoglobulin G in serum, as sputum culture lacks sensitivity. Differential diagnosis includes mycobacterial infection, bacterial lung abscess or necrotizing pneumonia, lung cancer, and endemic fungi.The aim of antifungal treatment in CPA is to improve symptoms and quality of life, and to halt progression, and possibly reverse radiological changes. Current recommendations suggest treatment for 6 months, although in practice many patients remain on long-term treatment. Improvement may manifest as weight gain and improvement of symptoms such as productive cough, hemoptysis, and fatigue. Surgical management should be considered in cases of diagnostic uncertainty, in significant hemoptysis, and when there is concern for lack of response to therapy. Itraconazole and voriconazole are the first-line azoles, with more experience now accumulating with posaconazole and isavuconazole. Side effects are frequent and careful monitoring including therapeutic drug monitoring is essential. Intravenous antifungals such as echinocandins and amphotericin B are used in cases of azole intolerance or resistance, which often develop on treatment. Relapse is seen after completion of antifungal therapy in around 20% of cases, mostly in bilateral, high-burden disease.Several research priorities have been identified, including characterization of immune defects and genetic variants linked to CPA, pathogenetic mechanisms of Aspergillus adaptation in the lung environment, the contribution of non-fumigatus Aspergillus species, and the role of new antifungal agents, immunotherapy, and combination therapy.

Outcomes of Intermittent Multidrug IV Therapy for Refractory Mycobacterium abscessus Pulmonary Disease

BACKGROUND

No studies have reported therapies for the treatment of patients with refractory Mycobacterium abscessus pulmonary disease (MAB-PD). We implemented intermittent multidrug IV therapy (IMIT) through repeated hospitalizations for patients with MAB-PD who were refractory to antibiotics for more than 12 months.

RESEARCH QUESTION

What are the effects of IMIT on patients with refractory MAB-PD?

STUDY DESIGN AND METHODS

The IV antibiotics administered for IMIT included amikacin, imipenem, and tigecycline, and the outcomes for 36 patients who underwent IMIT for refractory MAB-PD were evaluated. Patients were repeatedly hospitalized and administered IMIT on recurrent symptoms or radiographic evidence of deterioration, while maintaining oral/inhaled antibiotics.

RESULTS

Of the 36 patients, 26 (72%) had M abscessus subspecies abscessus (herein, M abscessus)-PD, and 10 (28%) had M abscessus subspecies massiliense (herein, M massiliense)-PD. The median number of hospitalizations for IMIT was two (interquartile range, 1-3) for patients with M abscessus-PD and one (interquartile range, 1-2) for patients with M massiliense-PD. At least one negative culture result and culture conversion were observed in 62% and 12% of patients with M abscessus-PD, and in 80% and 60% of patients with M massiliense-PD, respectively. Symptomatic improvement was observed in all patients, and radiologic improvement, including cavity amelioration or no deterioration, was observed in 42% and 70% of patients with M abscessus-PD and with M massiliense-PD, respectively. No resistance to clarithromycin or amikacin was acquired.

INTERPRETATION

IMIT with intermittent hospitalization can be a beneficial palliative treatment for patients with refractory MAB-PD. This therapy alleviated symptoms, slowed radiologic progression, and reduced the bacterial burden in some patients. However, radiologic and microbiological responses to IMIT were more apparent in M massiliense-PD than in M abscessus-PD.

Challenges and knowledge gaps in the management of non-tuberculous mycobacterial pulmonary disease in sub-Saharan African countries with a high tuberculosis burden: a scoping review

INTRODUCTION

In sub-Saharan African (SSA) countries endemic for tuberculosis (TB), previous TB is a significant risk factor for non-tuberculous mycobacterial pulmonary disease (NTM-PD). The deployment of GeneXpert MTB/RIF in pulmonary TB diagnostic work-up regularly identifies symptomatic patients with a positive smear microscopy but negative GeneXpert, indicative of NTM presence. This scoping review outlines recent evidence for NTM-PD diagnosis and management in SSA.

OBJECTIVE

The review's objective was to outline the risk factors, available diagnostics, management options and outcomes of NTM-PD in high-burden TB settings in SSA using the population-concept-context framework.

DESIGN AND DATA SOURCES

We searched existing literature from PubMed, Web of Science, African Journals Online, Google Scholar and grey literature. Studies published between January 2005 and December 2022 were retained. Data were extracted into Rayyan software and Mendeley and summarised using Excel.

RESULTS

We identified 785 potential articles, of which 105 were included in the full-text review, with 7 papers retained. Included articles used international criteria for diagnosing NTM-PD. Multiple papers were excluded due to non-application of the criteria, suggesting challenging application in the SSA setting. Identified risk factors include previous TB, smoking and mining. Most commonly, chest radiography and not CT was used for the radiological diagnosis of PD, which may miss early changes related to NTM-PD. Molecular methods for NTM species identification were employed in research settings, usually at referral centres, but were unavailable for routine care. Most studies did not report a standardised approach to treatment and they were not offered treatment for the specific disease, marking a lack of guidance in treatment decision-making. When treatment was provided, the outcome was often not reported due to the lack of implementation of standardised outcome definitions.

CONCLUSIONS

These outlined challenges present a unique opportunity for researchers to undertake further studies in NTM-PD and proffer solutions more applicable to SSA.

Change of erythrocyte sedimentation rate as prognostic biomarker for Mycobacterium avium complex pulmonary disease through anti-mycobacterial treatment

BACKGROUND

It remains unclear whether erythrocyte sedimentation rate (ESR) accurately predicts prognosis during treatment and how ESR changes.

OBJECTIVES

We aimed to assess the predictive values of ESR as a prognostic factor of Mycobacterium avium complex pulmonary disease (MAC-PD) while on anti-mycobacterial treatment and its changes according to the treatment responses.

DESIGN

This study is a retrospective cohort study.

METHODS

This study included patients aged 18 years or older who initiated anti-mycobacterial treatment for MAC-PD at Seoul National University Hospital between January 1, 2009 and March 31, 2022. ESR should be measured at least twice, with a minimum interval of 3 months, during the initial 12 months from the commencement of antibiotic treatment. A mixed linear regression and Cox proportional-hazards models were used to analyze repeated ESR data and the association with patient survival.

RESULTS

Of a total of 825 patients who initiated antibiotic treatment for MAC-PD, 369 patients were included in the analysis. Increased levels of ESR during the treatment process were associated with a higher risk of mortality (adjusted hazard ratio 1.03; 95% confidence interval, 1.02-1.03) after adjusting age, sex, comorbidities, presence of cavity, acid-fast bacilli smear positivity, and culture conversion at 12 months. During the treatment, ESR at 12 months of treatment significantly decreased compared to baseline ESR in both the culture-converted and not-converted groups, which was categorized based on whether the culture conversion was achieved within the 12 months after treatment initiation.

CONCLUSION

ESR predicted mortality during treatment and decreased over time, regardless of treatment outcomes. Our results underscore the importance of administering anti-mycobacterial treatment even in patients who did not achieve a microbiological cure.

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.

Diagnostic Criteria and the Decision to Treat Nontuberculous Mycobacterial Pulmonary Disease

The diagnosis of nontuberculous mycobacterial (NTM) pulmonary disease is based on three criteria: patient's symptoms, radiographic findings, and microbiologic results. The microbiologic criterion is the most complicated because it requires more than one positive sputum acid-fast bacilli culture. Clinicians are challenged to apply the diagnostic criteria in the context of variable patient symptoms, NTM pathogenicity, and host susceptibility. The decision to treat NTM pulmonary disease entails assessment of the risks and benefits of therapy and the patient's wishes and ability to receive treatment.

Non-tuberculous mycobacteria disease pre-lung transplantation: A systematic review of the treatment regimens and duration pre- and post-transplant

BACKGROUND

There is lack of consensus on non-tuberculous mycobacteria pulmonary disease (NTM-PD) treatment regimen and duration in patient listed for lung transplantation (LTx). We conducted a systematic review on treatment regimen and duration pre- and directly post-LTx, for patients with known NTM-PD pre-LTx. Additionally, we searched for risk factors for NTM disease development post-LTx and for mortality.

METHODS

Literature was reviewed on PubMed, Embase and the Cochrane Library, for articles published from inception to January 2022. Individual patient data were sought.

RESULTS

Sixteen studies were included reporting 92 patients. Most frequent used agents were aminoglycosides and macrolides for Mycobacterium abscessus (M. abscessus) and macrolides and tuberculostatic agents for Mycobacterium avium complex (M. avium complex). The median treatment duration pre-LTx was 10 months (IQR 6-17) and 2 months (IQR 2-8) directly post-LTx. Longer treatment duration pre-LTx was observed in children and in patients with M. abscessus. 46% of the patients with NTM-PD pre-LTx developed NTM disease post-LTx, related mortality rate was 10%. Longer treatment duration pre-LTx (p < 0.001) and sputum non-conversion pre-LTx (p = 0.003) were significantly associated with development of NTM-disease post-LTx. Longer treatment duration pre-LTx (p = 0.004), younger age (p < 0.001) and sputum non-conversion (p = 0.044) were risk factors for NTM related death.

CONCLUSIONS

The median treatment duration pre-LTx was 10 months (IQR 6-17) and 2 months (IQR 2-8) directly post-LTx. Patients with longer treatment duration for NTM-PD pre-LTx and with sputum non-conversion are at risk for NTM disease post-LTx and for NTM-related death. Children were particularly at risk for NTM related death.

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.

Clinical Impact of Chronic Pulmonary Aspergillosis in Patients with Nontuberculous Mycobacterial Pulmonary Disease and Role of Computed Tomography in the Diagnosis

Objective Chronic pulmonary aspergillosis (CPA) is an important complication of nontuberculous mycobacterial pulmonary disease (NTM-PD). However, its diagnosis is challenging, as both CPA and NTM-PD present as chronic cavitary disease. The present study evaluated the impact of CPA on the survival of patients with NTM-PD and revealed the key computed tomography findings for a prompt diagnosis. Methods We retrospectively reviewed patients newly diagnosed with NTM-PD in Tenri Hospital (Tenri City, Nara Prefecture, Japan) between January 2009 and March 2018; the patients were followed up until May 2021. Clinical and radiological characteristics were assessed, and patients with CPA were identified. Results A total of 611 patients were diagnosed with NTM-PD. Among them, 38 (6.2%), 102 (17%), and 471 (77%) patients were diagnosed with NTM-PD with CPA, cavitary NTM-PD without CPA, and non-cavitary NTM-PD without CPA, respectively. The 5-year survival rate of the NTM-PD with CPA group (42.8%; 95% confidence interval: 28.7-64.0%) was lower than that of the cavitary NTM-PD without CPA group (74.4%; 95% confidence interval: 65.4-84.6%). A multivariate analysis revealed that fungal balls and cavities with adjacent extrapleural fat were significant predictive factors for NTM-PD with CPA. Conclusion NTM-PD with CPA patients exhibited a worse prognosis than cavitary NTM-PD without CPA patients. Therefore, an unerring diagnosis of CPA is essential for managing patients with NTM-PD. Computed tomography findings, such as fungal balls and cavities with adjacent extrapleural fat, may be valuable diagnostic clues when CPA is suspected in patients with NTM-PD.

A Systematic Review of Factors Associated with Mortality among Patients with Mycobacterium avium Complex Lung Disease

PURPOSE

As the number of patients with Mycobacterium avium complex lung disease is significantly increasing worldwide, several studies have focused on the prognostic factors associated with the disease. This systematic review investigated the factors associated with mortality among patients with Mycobacterium avium complex lung disease.

METHODS

Two investigators independently identified studies that were designed to determine risk factors for mortality in patients with Mycobacterium avium complex lung disease from PubMed, the Cochrane Register of Control Trial database, and EMBASE (accessed on 25 November 2022).

RESULTS

Of the 1133 titles and abstracts screened, 54 full texts were selected for review, and 15 studies were finally included in this systematic review. The most commonly studied risk factors were advanced age and low body mass index (11 studies for each), followed by male sex (8 studies), hypoalbuminemia (5 studies), and cavity (5 studies). In each study, these factors were mostly associated with increased all-cause mortality among patients with Mycobacterium avium complex lung disease as confirmed via multivariate analysis.

CONCLUSIONS

Advanced age, male sex, low body mass index, hypoalbuminemia, and cavity are likely to be the common risk factors for all-cause mortality among patients with Mycobacterium avium complex lung disease, suggesting that patients with these factors need to be carefully monitored.

Multiple bacterial culture positivity reflects the severity and prognosis as bronchiectasis in Mycobacterium avium complex pulmonary disease

BACKGROUND

Bacterial coinfections are observed in 19-66% of patients with Mycobacterium avium complex pulmonary disease (MAC-PD) during the entire duration of the disease. The impact of bacterial coinfection at diagnosis on the clinical course of MAC-PD has not been reported.

METHODS

Among 558 patients diagnosed with MAC-PD between January 2016 and December 2020, 218 patients who underwent sputum culture tests twice or more within one year before and after diagnosis were included. We compared the patient characteristics and disease courses between the patients who had the same bacterial species detected twice or more (bacterial culture positive group: BCP group) and those who never had bacteria cultured (bacterial culture negative group: BCN group).

RESULTS

We included 70 patients in the BCP group and 74 in the BCN group. The radiological findings showed that BCP at diagnosis correlated with a high modified Reiff score. During the median follow-up period of 42 months, the patients in the BCP group were more likely to accomplish spontaneous sputum conversion of MAC. The treatment initiation rate for MAC-PD in the BCP group was lower than that in the BCN group (41.4% vs. 67.6%, P = 0.003). In contrast, the time to the first bronchiectasis exacerbation in the BCP group was shorter than that in the BCN group, and the frequency of bronchiectasis exacerbations was higher in the BCP group.

CONCLUSIONS

Patients with BCP at diagnosis are less likely to initiate treatment for MAC-PD and more likely to develop bronchiectasis exacerbation.