Nontuberculous Mycobacterial Pulmonary Disease Research Articles

Prevalence of Chronic Obstructive Pulmonary Disease in Patients with Nontuberculous Mycobacterial Pulmonary Disease: A Systemic Review and Meta-Analysis

Background/Objectives: Nontuberculous mycobacterial pulmonary disease (NTM-PD) is an important comorbidity of COPD. Although many studies have reported an association between COPD and NTM-PD, no clear estimate of the prevalence of COPD and its effects on survival times in patients with NTM-PD is available. This study aimed to investigate the prevalence of COPD and its impact on survival in patients with NTM-PD. Methods: All studies reporting the prevalence of COPD in patients with NTM between 1952 and 2021 were searched using PubMed in May 2023. The inclusion criteria were studies about patients with NTM and COPD. A random-effects meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: The pooled overall prevalence of COPD in patients with NTM-PD was 28% (95% confidence interval [CI], 22–35). Patients with NTM-PD were six times more likely to have COPD than those without NTM-PD (pooled odds ratio [OR], 6.26; 95% CI, 3.37–11.65). Male patients with NTM-PD had a four-fold higher risk of COPD than females (OR, 3.81; 95% CI, 1.18–12.35). The co-existence of COPD and NTM-PD was significantly associated with an increased risk of mortality compared with NTM-PD without COPD (OR, 3.65; 95% CI, 1.28–10.40). Conclusions: COPD is common in patients with NTM-PD, and patients with NTM-PD had a six-fold increase in the odds of having COPD than those without NTM-PD. The presence of COPD and NTM-PD had a significant negative effect on survival. These findings may support the need to assess the presence of COPD in patients with NTM-PD and the potential negative effects associated with the co-existence of COPD and NTM-PD.

Preliminary investigation of the significance of cavitary lesions in recurrent hemoptysis following bronchial artery embolization for nontuberculous mycobacterial pulmonary disease

BackgroundNontuberculous mycobacterial pulmonary disease (NTM-PD) varies widely in clinical presentation, and some patients experience hemoptysis. Bronchial artery embolization (BAE) is a treatment option for hemoptysis caused by NTM-PD. However, the association between post-BAE rebleeding risk and the presence of cavitary lesions has not been fully elucidated. MethodsA retrospective observational study was conducted on patients with NTM-PD who had undergone BAE at our institution. Patients were classified into Cavitary and Non-cavitary groups, and baseline characteristics and clinical outcomes were compared. ResultsAmong the 155 BAE cases between 2013 and 2023, 18 were included in the analysis, and four experienced rebleeding. The Cavitary group tended to have a higher rebleeding rate 24 months after BAE (37.5% vs. 10.0%, p=0.27). Furthermore, the Cavitary group showed a significantly higher number of non-bronchial arteries involved (median number: 1.5 vs. 0.0, p=0.02), a higher proportion of patients with a prior antibiotic treatment history (100% vs. 20%, p=0.001), and longer duration from diagnosis to BAE (median year: 9.0 vs. 0.6, p=0.02). The Kaplan-Meier curves showed a tendency for shorter rebleeding-free survival in the Cavitary group (p=0.10). ConclusionsCavitary lesions in patients with NTM-PD may predict higher rebleeding rates after BAE. Further research with larger cohorts is needed to better understand rebleeding risk factors in BAE for NTM-PD.

Significance of in-vivo biofilm in non-tuberculous mycobacterial diseases

There’s been a rise of pulmonary non-tuberculous mycobacterial (NTM) disease in developed countries. Treatment for this is limited and existing treatments have an extensive duration. The disease has a long latent period and often experiences recurrence after treatment. In their work, Senior Research Scientist Dr Kentaro Yamamoto and his team based at the Leprosy Research Centre within the Department of Mycobacteriology, National Institute of Infectious Diseases (NIID) are building on the recent discovery that NTMs form biofilms in infected tissues. There is potential that biofilms formed in infected tissues could shield the bacilli from drug exposure, protect them against the host’s immune system attacks, or offer a refuge for the bacilli within the human body. Therefore the researchers believe that the removal of biofilms formed by NTMs or M. tuberculosis in the body could represent a novel treatment approach. By developing a device that can easily detect mycobacterial biofilms within the body, it would be possible to non-invasively assess a patient’s condition, including the stage of infection. Much remains to be discovered about the structure and function of mycobacterial biofilms in vivo and so the researchers want to clarify the relationship between biofilm formation in the lungs and key factors such as pathogenicity, bacterial growth, drug resistance, host immune response and the phenomena of latency and recurrence. If the team can make these clarifications, the research will benefit patients who are allergic to antimicrobials and those whose quality of life is reduced by the long-term treatment of NTM disease.

Executive Summary: State-of-the-Art Review: Nontuberculous Mycobacterial Pulmonary Disease: Patients, Principles, and Prospects.

Executive Summary: State-of-the-Art Review: Nontuberculous Mycobacterial Pulmonary Disease: Patients, Principles, and Prospects.

Impact of bacterial co-isolation on treatment initiation and long-term prognosis of patients with nontuberculous mycobacterial pulmonary disease: analysis of a prospective cohort study.

Nontuberculous mycobacterial pulmonary disease (NTM-PD), a chronic respiratory condition, presents a growing challenge globally. Uncertainties exist regarding the impact of concurrent bacterial co-isolation on treatment initiation and long-term prognosis. This study analysed data from participants enrolled in an ongoing prospective observational cohort study on NTM-PD (NCT01616745) between 1 July 2011, and 31 December 2022, who provided sputum samples for bacterial culture at enrolment. Identification of potential pathogenic microorganisms (PPMs) was defined as a positive bacterial culture. Clinical characteristics were compared between NTM-PD patients with Pseudomonas, non-pseudomonal PPMs, and those without PPM co-isolation. Cox proportional hazard regression models were employed to assess the association of bacterial co-isolation with rates of NTM-PD treatment initiation and all-cause mortality. Overall, 453 patients (median age, 62 years; 30% male) were included in the analysis. PPMs were co-isolated in 77 patients (17%), including 13 with Pseudomonas species. Co-isolation of Pseudomonas was associated with a significantly higher erythrocyte sedimentation rate (P = 0.02) and St. George's Respiratory Questionnaire score (P = 0.01). Non-pseudomonal PPM co-isolation was significantly associated with a higher likelihood of NTM-PD treatment initiation (adjusted hazards ratio [aHR], 1.56, 95% confidence interval [CI], 1.03-2.36, P = 0.036), whereas co-isolation of Pseudomonas was independently correlated with increased all-cause mortality (aHR, 3.25, 95% CI, 1.08-9.84, P = 0.037). Our findings emphasize the importance of microbial surveillance, as bacterial co-isolation affects treatment initiation and prognosis in patients with NTM-PD.

Diagnostic Value of Targeted Next-generation Sequencing in Pulmonary Mycobacterial Infections.

This study aimed to explore the diagnostic value of novel technique-targeted next-generation sequencing (tNGS) of bronchoalveolar lavage fluid (BALF) in pulmonary mycobacterial infections. This retrospective study was conducted on patients who underwent bronchoscopy and tNGS, smear microscopy, and mycobacterial culture of BALF. Patients with positive Mycobacterium tuberculosis (MTB) culture or GeneXpert results were classified into the tuberculosis case group. Those diagnosed with nontuberculous mycobacteria (NTM)-pulmonary disease (NTM-PD) composed the case group of NTM-PD patients. The control group comprised patients without tuberculosis or NTM-PD. Sensitivity, specificity, and receiver operating characteristic (ROC) curves were used to evaluate the diagnostic performance. For tuberculosis patients with positive mycobacterial culture results, the areas under the ROC curves (AUCs) for tNGS, GeneXpert, and smear microscopy were 0.975 (95% CI: 0.935, 1.000), 0.925 (95% CI: 0.859, 0.991), and 0.675 (95% CI: 0.563, 0.787), respectively. For tuberculosis patients with positive GeneXpert results, the AUCs of tNGS, culture, and smear microscopy were 0.970 (95% CI: 0.931, 1.000), 0.850 (95% CI: 0.770, 0.930), and 0.680 (95% CI: 0.579, 0.781), respectively. For NTM-PD, the AUCs of tNGS, culture, and smear-positive but GeneXpert-negative results were 0.987 (95% CI: 0.967, 1.000), 0.750 (95% CI: 0.622, 0.878), and 0.615 (95% CI: 0.479, 0.752), respectively. The sensitivity and specificity of tNGS in NTM-PD patients were 100% and 97.5%, respectively. tNGS demonstrated superior diagnostic efficacy in mycobacterial infection, indicating its potential for clinical application.

Nontuberculous mycobacterial pulmonary disease (NTM PD) incidence trends in the United States, 2010–2019

BackgroundNontuberculous mycobacteria (NTM) are ubiquitous environmental bacteria that cause chronic lung disease. Rates of NTM pulmonary disease (NTM PD) have increased over the last several decades, yet national estimates in the United States (US) have not been assessed since 2015.MethodsWe used a nationally representative population of Medicare beneficiaries aged ≥ 65 years to assess rates of NTM PD in a high-risk population from 2010 to 2019. Poisson generalized linear models were used to assess the annual percent change in incidence in the overall population and among key demographic groups such as sex, geography, and race/ethnicity. We evaluated the relative prevalence of various comorbid conditions previously found to be associated with NTM PD.ResultsWe identified 59,724 cases of incident NTM PD from 2010 to 2019 from an annual mean population of 29,687,097 beneficiaries, with an average annual incidence of 20.1 per 100,000 population. NTM PD incidence was overall highest in the South and among women, Asian individuals, and persons aged ≥ 80 years relative to other studied demographic groups. The annual percent change in NTM PD incidence was highest in the Northeast, at 6.5%, and Midwest, at 5.9%, and among women, at 6.5%. Several comorbid conditions were highly associated with concurrent NTM diagnosis, including allergic bronchopulmonary aspergillosis, bronchiectasis, and cystic fibrosis.ConclusionsHere we provide current estimates of NTM PD incidence and prevalence and describe increasing trends in the US from 2010 to 2019. Our study suggests a need for improved healthcare planning to handle an increased future caseload, as well as improved diagnostics and therapeutics to better detect and treat NTM PD in populations aged ≥ 65 years.

Nontuberculous mycobacterial pulmonary disease caused by Mycobacterium seoulense.

Mycobacterium seoulense was first isolated and reported in Korea in 2007. We report a rare case of nontuberculous mycobacterial (NTM) pulmonary disease caused by M. seoulense. A woman in her mid-90s was referred to our hospital due to bloody sputum. She had medical histories of chronic heart failure and chemoradiotherapy for right small cell lung carcinoma. Chest computed tomography showed a consolidation on the mediastinal side of the right lung following radiotherapy and nodules with bronchiectasis of the right upper and middle lobes. Acid-fast culture tests of sputum were positive for M. seoulense. We are currently treating her with tranexamic acid and carbazochrome sodium sulfonate and conducting careful follow-up. M. seoulense infection may need to be recognized as one of the notable NTM pulmonary diseases presenting with respiratory symptoms and radiological findings.

The effect of smoking on nontuberculous mycobacterial pulmonary disease and tuberculosis: a nationwide retrospective cohort study.

Although smoking is an established risk factor for Mycobacterial infection, the association between smoking and nontuberculous mycobacterial pulmonary disease (NTM-PD) remains unclear. We evaluated the association between smoking and NTM-PD and tuberculosis (TB) using a population-based South Korean nationwide cohort. Using the Korean National Health Insurance Database, we screened individuals over 20years of age who underwent the national health screening program in 2009. Out of 3,774,308 eligible populations, we identified 2,964 and 26,112 cases of newly developed NTM-PD and TB, respectively. We used multivariate Cox proportional hazards models to estimate the adjusted hazard ratios (aHRs) of risk factors for NTM-PD and TB. The incidence rates for developing NTM-PD and TB were 0.08 and 0.68 per 1,000 person-years, respectively. Current smokers (aHR 0.63, 95% confidence interval [CI] 0.56-0.71) and current heavy smokers (≥ 20 pack-years, aHR 0.74, 95% CI 0.63-0.86) were at lower risk for NTM-PD development than never smokers. On the contrary, current smokers (aHR 1.19, 95% CI 1.15-1.23) and current heavy smokers (aHR 1.27, 95% CI 1.22-1.33) had a higher risk for TB development than never smokers. These trends were augmented if individuals started smoking before age 20years. In subgroup analyses stratified by age, these trends were prominent in the 40-64years age range. Current smoking was associated with a decreased risk of NTM-PD and increased risk of TB. These risks were augmented by early smoking initiation and in the middle age population.

A novel hematological score (HS) and its related nomogram model to predict nontuberculous mycobacterial pulmonary disease in patients with suspected multidrug-resistant pulmonary tuberculosis

Background Nontuberculous mycobacteria pulmonary disease (NTM-PD) exhibits clinical and radiological characteristics similar to those of pulmonary tuberculosis (PTB). This study aimed to develop a novel hematological score (HS) and its related nomogram model to identify NTM-PD in patients with suspected multidrug-resistant pulmonary tuberculosis (SMDR-PTB) due to lack of response to first-line anti-TB treatment (ATT). Methods We retrospectively recruited patients with SMDR-PTB from Wuhan Jinyintan Hospital between January 2014 and January 2022. These patients were divided into NTM-PD and MDR-PTB groups based on pathogen test results. Participants were randomly allocated to training and validation set in a 7:3 ratio. The ROC and LASSO regression were employed to select variables. Multivariate logistic analysis was conducted on the training set to develop the HS and its related nomogram models, followed by internal validation on the validation set. Results The HS was constructed and developed on CKMB, ADA, GGT, LDL, and UHR, demonstrating good predictive value with AUCs of 0.900 and 0.867 in the training and validation sets, respectively. The HS-based nomogram model consists of Age, Gender, DM, HIV infection, ILD and HS, and exhibited strong discriminative ability, accuracy, and clinical utility in two sets. The AUCs were 0.930 and 0.948 in the training set and validation set, respectively. Conclusion HS may be a useful biomarker for identifying NTM-PD in patients with SMDR-PTB. The HS-based nomogram model serves as a convenient and efficient tool for guiding the treatment of SMDR-PTB patients.

Epidemiological trends and clinical relevance of nontuberculous mycobacterial pulmonary disease in a referral hospital in Japan, 2017–2021

BackgroundEpidemiological trends and clinical relevance of NTM species in Japan following the adoption of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry remain unclear. MethodsWe analyzed the results of mycobacterial culture tests of respiratory specimens collected between January 2017 and December 2021. We assessed the clinical relevance of NTM species by analyzing the proportion of patients diagnosed with NTM pulmonary infection (NTM-PI). We illustrated the incidence and clinical relevance of each NTM species using a two-dimensional scatter plot. Medical chart review and radiological analysis were also performed for less common species. ResultsAmong 65,368 respiratory specimens tested for acid-fast bacilli, NTM were identified in 12,802 specimens from 3177 patients. The number of incident cases with NTM-PI has continued to increase. Notably, the number of incident cases with M. abscessus species (MABS) was continuously increasing and accounted for 10.6% of all incident cases with NTM-PI. The clinical relevance of the common NTM species, M. avium complex, MABS and M. kansasii, ranged from 57 to 72%. Seven other species exhibited a higher clinical relevance than these common NTM species, with M. shinjukuense (100%) having the highest clinical relevance. On the other hand, 11 species, including M. fortuitum (32.4%), M. xenopi (20.0%), and M. gordonae (22.9%), showed clinical relevance below 50%. ConclusionsThe present study clarified the incidence and clinical relevance of NTM species using a two-dimensional scatter plot, which could serve as a useful tool for clinical decision-making and future epidemiological research.

A retrospective study differentiating nontuberculous mycobacterial pulmonary disease from pulmonary tuberculosis on computed tomography using radiomics and machine learning algorithms

Objective To evaluate the effectiveness of a machine learning based on computed tomography (CT) radiomics to distinguish nontuberculous mycobacterial pulmonary disease (NTM-PD) from pulmonary tuberculosis (PTB). Methods In this retrospective analysis, medical records of 99 individuals afflicted with NTM-PD and 285 individuals with PTB in Zhejiang Chinese and Western Medicine Integrated Hospital were examined. Random numbers generated by a computer were utilized to stratify the study cohort, with 80% designated as the training cohort and 20% as the validation cohort. A total of 2153 radiomics features were extracted using Python (Pyradiomics package) to analyse the CT characteristics of the large disease areas. The identification of significant factors was conducted through the least absolute shrinkage and selection operator (LASSO) regression. The following four supervised learning classifier models were developed: random forest (RF), support vector machine (SVM), logistic regression (LR), and extreme gradient boosting (XGBoost). For assessment and comparison of the predictive performance among these models, receiver-operating characteristic (ROC) curves and the areas under the ROC curves (AUCs) were employed. Results The Student’s t-test, Levene test, and LASSO algorithm collectively selected 23 optimal features. ROC analysis was then conducted, with the respective AUC values of the XGBoost, LR, SVM, and RF models recorded to be 1, 0.9044, 0.8868, and 0.7982 in the training cohort. In the validation cohort, the respective AUC values of the XGBoost, LR, SVM, and RF models were 0.8358, 0.8085, 0.87739, and 0.7759. The DeLong test results noted the lack of remarkable variation across the models. Conclusion The CT radiomics features can help distinguish between NTM-PD and PTB. Among the four classifiers, SVM showed a stable performance in effectively identifying these two diseases.

Laboratory-based surveillance of non-tuberculous mycobacterial pulmonary disease in Japan

BackgroundIntractable pulmonary diseases with non-tuberculous mycobacteria (NTM-PDs) and antimicrobial resistance have become increasingly concerning worldwide. Nevertheless, a surveillance system for NTM has not been established in most countries, thus requiring repeated, intermittent, and time-consuming cross-sectional nationwide surveys.MethodsTo establish a nationwide surveillance system for NTM-associated diseases, we aimed to develop a prototype computer system primarily designed to continuously estimate NTM-PD incidence using a bacteriological case-defining algorithm through an automatic process of integrating bacteriological data collected from microbiology laboratories across Japan. To validate the accuracy of our study results, we compared the distribution of pulmonary TB cases between our laboratory data and the national surveillance data, which is representative of the Japanese population.ResultsOur estimates implied a 17.7% increase in NTM-PD incidence from 15.8 [14.9–16.8] in 2013 to 19.2 [18.2–20.4] in 2017, per 100 000 population. Moreover, 93.0% of the identified NTM-PD cases were dominated by theMycobacterium avium-intracellularecomplex, and the proportion ofM. abscessusspecies exceeded that ofM. kansasiifor the first time in Japan. We also revealed significant age and sex differences in NTM-PDs. Notably, we found similar characteristics between our laboratory data and national surveillance data covering almost the entire Japanese population.ConclusionThese findings, despite being laboratory-based, are extrapolatable to the general population in Japan and provide evidence that supports our system as a viable alternative to the nationwide NTM surveillance system.

Risk of incident chronic obstructive pulmonary disease during longitudinal follow-up in patients with nontuberculous mycobacterial pulmonary disease

BackgroundThe Global Initiative for Chronic Obstructive Lung Disease 2023 revision proposed that chronic obstructive pulmonary disease (COPD) has various etiologies including infections (COPD-I), such as tuberculosis and human immunodeficiency virus. While nontuberculous mycobacterial pulmonary disease (NTM-PD) and pulmonary tuberculosis share similar clinical manifestations, research on COPD development during longitudinal follow-up in patients with NTM-PD is limited. In this study, we aimed to evaluate the incidence and risk of COPD development in patients with NTM-PD.MethodsWe retrospectively enrolled patients with NTM-PD with normal lung function and 1:4 age-, sex-, body mass index-, and smoking status-matched controls between November 1994 and January 2022. We compared the risks of spirometry-defined COPD between the NTM-PD and control groups (study 1). A nationwide cohort study using the health insurance claims database was conducted to validate the findings (study 2).ResultsIn study 1, during a mean follow-up of 3.3 years, COPD occurred in 14.0% (241/1,715) and 4.3% (293/6,860) of individuals in the NTM-PD and matched control cohorts, respectively. The NTM-PD cohort exhibited a higher risk of incident COPD (adjusted hazard ratio [aHR], 2.57; 95% CI, 2.15–3.09) compared to matched controls. In study 2, COPD occurred in 6.2% (24/386) and 2.5% (28/1,133) of individuals with and without NTM-PD, respectively. The NTM-PD cohort had a higher risk of incident COPD (aHR, 2.04; 95% CI, 1.21–3.42) compared to matched controls.ConclusionThese findings suggest that NTM-PD could be considered a new etiotype of COPD-I and emphasize the importance of monitoring lung function in individuals with NTM-PD.

Nontuberculous mycobacterial pulmonary disease presenting as bronchiolitis pattern on CT without cavity or bronchiectasis

BackgroundThis study aimed to investigate the radiological changes in patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) having bronchiolitis patterns on computed tomography (CT).MethodsWe retrospectively reviewed the final diagnosis and radiologic changes of patients suspected of having NTM-PD without cavity or bronchiectasis on CT image, between January 1, 2005 and March 31, 2021. NTM-PD was diagnosed based on the American Thoracic Society and Infectious Diseases Society of America criteria. The initial and final CT findings (bronchiectasis, cellular bronchiolitis, cavity formation, nodules, and consolidation) were compared between patients diagnosed with and without NTM-PD.ResultsThis study included 96 patients and 515 CT images. The median CT follow-up duration was 1510.5 (interquartile range: 862.2–3005) days. NTM-PD was recognized in 43 patients. The clinical variables were not significantly different between patients with and without NTM-PD, except for underlying chronic airway disease (P < 0.001). Nodule and consolidation were more frequently observed on the initial CT scans of patients with NTM-PD compared with those without (P < 0.05). On the final follow-up CT scan, bronchiectasis (P < 0.001), cavity (P < 0.05), nodule (P < 0.05), and consolidation (P < 0.05) were more frequently observed in patients with NTM-PD. Among the 43 patients with NTM-PD, 30 showed a radiological progression on CT, with bronchiectasis (n = 22) being the most common finding. The incidence of bronchiectasis increased over time.ConclusionThe bronchiolitis pattern on CT images of patients with NTM-PD showed frequent radiological progression during the follow-up period.

Clinical Characteristics of Patients with Nontuberculous Mycobacterium Pulmonary Disease in Fuyang, China: A Retrospective Study.

We retrospectively review consecutive patients with nontuberculous mycobacterium (NTM) pulmonary disease reported from a designated hospital for infectious diseases in the Fuyang district of China to determine the clinical characteristics of these patients. This research enrolled 234 patients with NTM pulmonary disease between January 2018 and May 2023 in the Fuyang district of China. Data were collected from the electronic medical records. The NTM strain composition and clinical characteristics of NTM pulmonary disease were retrospectively analyzed. 73 (31.20%) patients had previous tuberculosis (TB) or TB exposure history and bronchiectasis. Mixed NTM infection accounted for 12.39%. Mycobacterium intracellulare strain was detected in 132 patients (49.62%). Women were found to be more affected by Mycobacterium avium infection, and men by Mycobacterium abscessus infection. Mycobacterium avium (34.21%) and Mycobacterium abscessus (33.33%) strains were most common in people with previous TB or TB exposure history. Among respiratory tract-related diseases, patients with bronchiectasis had the highest isolation rate of Mycobacterium avium (55.36%). Women were susceptible to bronchiectasis (P <0.01). The median of mononuclear-to-lymphocyte ratio (MLR) was higher in men than in women (P < 0.01). The serum albumin (ALB) level was lower in patients with TB or TB exposure history than in those without TB history (P = 0.034). The prognostic nutritional index (PNI) was lower in patients with TB or TB exposure history than in those without tuberculosis history (P = 0.021). Patients with NTM lung disease were poorly treated. Clinical symptoms of the disease were not species-specific. Mycobacterium intracellulare and Mycobacterium avium strains were predominant in the Fuyang district of China. Previous TB or TB exposure history immensely enhanced the risk of NTM disease.

Characterization of non-tuberculous mycobacterial pulmonary disease and pulmonary tuberculosis in patients with AFB smear-positive sputum: A retrospective comparative study

BackgroundDistinguishing nontuberculous mycobacteria pulmonary disease (NTM-PD) from pulmonary tuberculosis (PTB) is a challenge especially in patients with positive sputum smear of acid-fast bacilli (AFB). This study aimed to compare and identify the clinical characteristics between the two diseases among patients with positive sputum AFB. MethodsFrom February 2017 through March 2021, patients with positive sputum AFB were reviewed in two hospitals of China. Among them, clinical data of NTM-PD and PTB patients was collected and compared. Results76 cases of NTM-PD and 92 cases of PTB were included in our study. When compared with PTB, NTM-PD patients were older (59.2 ± 11.4 vs 44.2 ± 19.5 years, P < 0.001) and manifested more hemoptysis and dyspnea (28.9 % vs 14.1 %, P < 0.05; 48.7 % vs 17.4 %, P < 0.001 respectively). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) for Xpert were 85.9 %, 96.1 %, 96.3 %, 84.9 %, respectively, compared to 94.2 %, 81.1 %, 83.1 %, 93.5 %, respectively for T-spot in diagnosing PTB. In radiological features, NTM-PD affected more lobes (4.53 ± 0.89 vs 3.61 ± 1.41, P < 0.001) and showed more consolidation (50 % vs 32.6 %, P < 0.05), destroyed lung (22.7 % vs 9.8 %, P < 0.05), honeycomb lung (26.7 % vs 6.5 %, P < 0.001) but less nodules (80.3 % vs 95.7 %, P < 0.05), tree-in-bud sign (49.3 % vs 87 %, P < 0.001), and satellite nodules (14.5 % vs 90.2 %, P < 0.001) than PTB. Age (odds ratio [OR], 1.043; 95 % confidence interval [CI], 1.018–1.069, P < 0.05), hemoptysis (OR, 3.552; 95%CI, 1.421–8.729, P < 0.05), and dyspnea (OR, 2.631; 95%CI, 1.151–6.016, P < 0.05) were independently correlated with NTM infection. ConclusionsNTM-PD and PTB share similar clinical manifestations. Among them, advanced age, hemoptysis, and dyspnea are the independent predictors for NTM infection. Xpert is an efficiency analysis in discriminating between NTM-PD and PTB in patients with positive sputum AFB.

Medical Costs of Nontuberculous Mycobacterial Pulmonary Disease, South Korea, 2015-2019.

Nontuberculous mycobacterial pulmonary disease (NTM-PD) prevalence is a rising public health concern. We assessed the long-term healthcare systems perspective of costs incurred by 147 NTM-PD patients at a tertiary hospital in South Korea. Median cumulative total medical cost in managing NTM-PD patients was US $5,044 (interquartile range US $3,586-$9,680) over 49.7 months (interquartile range 33.0-68.2 months) of follow-up. The major cost drivers were diagnostic testing and medication, accounting for 59.6% of total costs. Higher costs were associated with hospitalization for Mycobacterium abscessus infection and pulmonary comorbidities. Of the total medical care costs, 50.2% were patient co-payments resulting from limited national health insurance coverage. As South Korea faces significant problems of poverty during old age and increasing NTM-PD prevalence, the financial and socio-economic burden of NTM-PD may become a major public health concern that should be considered with regard to adequate strategies for NTM-PD patients.

The Association between Dyslipidemia and Pulmonary Diseases.

Dyslipidemia is one of the most common diseases worldwide. As a component of metabolic syndrome, the prevalence and mechanism by which dyslipidemia promotes cardiovascular diseases has been well studied, although the relationship between pulmonary diseases is not well understood. Because the lung is a respiratory organ with a large surface area and is exposed to the environment outside the body, it continuously inhales various substances. As a result, pulmonary diseases have a vast diversity, including chronic inflammatory diseases, allergic diseases, cancers, and infectious diseases. Recently, growing evidence has suggested that dyslipidemia plays a role in the pathogenesis and prognosis of various pulmonary diseases. We herein review the current understanding of the relationship between dyslipidemia and pulmonary diseases, including chronic obstructive pulmonary diseases, asthma, and lung cancer, and infectious pulmonary diseases, including community-acquired pneumonia, tuberculosis, nontuberculous mycobacterial pulmonary disease, and COVID-19. In addition, we focus on recent evidence of the utility of statins, specifically 3-hydroxy-3-methylglutaryl-coA reductase inhibitors, in the prevention and treatment of the various pulmonary diseases described above.

Lower respiratory tract microbiota in patients with clinically suspected nontuberculous mycobacterial pulmonary disease according to the presence of gastroesophageal reflux.

Although gastroesophageal reflux has been recognized as one of the risk factors of nontuberculous mycobacterial pulmonary disease (NTM-PD) progression, the effect of reflux on the lower respiratory tract microbiota has not been studied in detail. We investigated the composition of the lower respiratory tract microbiota in patients with clinically suspected NTM-PD, comparing them based on the presence of reflux. Forty-seven patients suspected of having NTM-PD were enrolled and assigned according to presence of reflux (n = 22) and non- reflux (n = 25). We performed a pepsin ELISA assay to identify the presence of reflux and 16S ribosomal RNA gene amplicon sequencing to evaluate the microbiota in bronchoalveolar lavage fluid. There were no significant differences in the diversity or composition of the lower respiratory microbiota between the NTM-PD and non-NTM-PD groups. Bacterial richness was observed in the non-reflux group than in the reflux group [P = 0.03] and a cluster in the reflux group was observed. The reflux group showed a predominance for Pseudomonas aeruginosa or Staphylococcus aureus among the NTM-PD group and for P. aeruginosa, Haemophilus influenzae, Klebsiella pneumoniae, or Eikenella species among the non-NTM-PD group. The non-reflux groups presented diverse patterns. A linear discriminant analysis and volcano plot demonstrated that P. aeruginosa, H. haemolyticus, Selenomonas artemidis, and Dolosigranulum pigrum were specifically associated with the NTM-PD reflux group, while P. aeruginosa was specifically associated with the non-NTM-PD reflux group. These observations confirm that the lower respiratory microbiota is consistently altered by reflux but not in NTM-PD.