Nontuberculous Mycobacterial Lung Research Articles

Nontuberculous mycobacterial skin and soft tissue infection in Hawai\u02bbi

BackgroundHawaiʻi has the highest nontuberculous mycobacterial (NTM) lung infection prevalence in the United States. Limited data regarding skin and soft tissue infections (SSTI) due to NTM in Hawaiʻi exists. This study describes patient demographics, clinical courses of infection, treatment patterns, and clinical outcomes of NTM SSTIs in Hawaiʻi.MethodsA retrospective chart review (n = 50) of patients diagnosed and treated at Hawaiʻi Pacific Health facilities for NTM SSTIs between January 2010 and July 2021 was conducted. Patient demographics, clinical course, and treatment data were collected from electronic medical records.ResultsHalf of the patient population consisted of females, and the average age of patients during infection was 49 years (SD = 25.6). The majority of cases (80%) were caused by rapidly growing mycobacteria (RGM), most commonly Mycobacterium abscessus. NTM SSTI by race were Asian (48%), White (28%), and Native Hawaiian and Other Pacific Islanders (16%). Almost all Asian patients with NTM SSTI were Filipino or Japanese. Diagnosis was frequently delayed. The average time to diagnosis was 116 days. Most patients achieved complete resolution (72%) following a prolonged course of antimicrobial treatment (mean = 196 days) with surgical debridement.ConclusionIncreased awareness among physicians and the community of non-mycobacterial skin infections is essential in Hawaiʻi due to the high prevalence of NTM and the high percentage of predisposed populations. Increased awareness of NTM could reduce delayed diagnosis and improve patient care. Further studies are required to inform optimal treatment and diagnostic strategies, improve patient outcomes, and aid public health surveillance efforts.

Microbiome in Pulmonary Tuberculosis, Non-tuberculous Mycobacterial Pulmonary Diseases, Lung Cancer and Hemoptysis

Microbiome in Pulmonary Tuberculosis, Non-tuberculous Mycobacterial Pulmonary Diseases, Lung Cancer and Hemoptysis

Clinical Analysis of Pulmonary Nontuberculous Mycobacterial Disease Complicated by Lung Cancer during the Follow-Up Periods

Introduction: The objective of this study was the estimation of the clinical characteristics of patients with pulmonary nontuberculous mycobacterial (NTM) disease complicated by lung cancer during the follow-up periods. Methods: We analyzed the clinical findings of four patients (2.0%) complicated by lung cancer during the follow-up periods of over six months at least after the definite diagnosis of pulmonary NTM disease of 202 patients with pulmonary NTM disease experienced in our hospital in the last decade. Results: There were four patients with pulmonary NTM disease complicated by lung cancer and all of them were caused by Mycobacterium avium complex (MAC). They were all elderly male patients and had underlying diseases. Three patients were diagnosed with primary lung cancer and one diagnosed with metastatic lung cancer from colon cancer within 3 years after the diagnosis of pulmonary NTM disease. The treatments for lung cancer were surgical resection for all patients with localized lesions. One patient died due to the worsening of underlying disease and the remaining three survived except for the recurrence of one patient. Conclusion: Although the complication rate of pulmonary NTM disease and lung cancer was a lower percentage (2.0%) than in previous reports, the careful follow-up for patients with pulmonary NTM disease without forgetting the possible complication of lung cancer is necessary.

WS02.3 Randomized, double-blind (DB), placebo-controlled study and open-label (OL) extension of liposomal amikacin for inhalation (LAI) in patients with refractory nontuberculous mycobacterial (NTM) lung disease (LD)

Objective NTM-LD management often requires lengthy multidrug antibiotic regimens (MDARs) and can be complicated by drug toxicity and poor prognosis. Efficacy, safety, and tolerability of LAI, a novel amikacin formulation, were evaluated in refractory NTM-LD. Methods In the 84-day DB phase, eligible patients whose NTM infection was refractory to guideline-based MDARs for ≥6 mo were stratified by presence/absence of CF and Mycobacterium avium complex (MAC) vs M. abscessus infection. Patients were randomized 1:1 to LAI 590 mg QD or placebo via nebulizer added to their ongoing stable MDARs. In the OL phase, eligible patients received LAI 590 mg QD for another 84 days. Efficacy endpoints included change from baseline on the full semi-quantitative scale for mycobacterial culture, NTM culture negativity, and distance walked on the 6-minute walk test (6MWT) up to Day 168. Adverse events were monitored up to Day 196. Results Of 136 screened patients, 90 were randomized (CF 19%, non-CF 81%; MAC 64%, M. abscessus 36%). 54% were aged >60 y; 31%, >40–60 y; 14%, 18–40 y. At end of study, 80 and 59 patients had completed the DB and OL phases, respectively. LAI achieved statistical significance in the clinically important endpoint of culture negativity at Day 84 (LAI vs placebo, mITT population: 11/44 vs 3/45 patients; P = 0.01) and in the 6MWT (LAI vs placebo: 23.90 vs −25.03 m; P = 0.009). Complete study results showing continuation of these trends will be presented. Conclusions Full study results will provide efficacy and safety profiles of LAI QD added to a MDAR. These data will increase understanding of NTM-LD, including shifting NTM-LD management paradigms.

Identification of nontuberculous mycobacterial infection by IS6110 and hsp65 gene analysis on lung tissues

The clinical, histologic, and radiographic presentations of nontuberculous mycobacterial (NTM) lung disease are usually indistinguishable from those of reactivated pulmonary tuberculosis (TB), so it remains a great challenge for the clinician to make treatment decisions for patients with old TB and a positive culture result for NTM. This study investigated whether the mycobacterial specific heat shock protein 65 (hsp65) and Mycobacterium tuberculosis (MTB)-specific IS6110 gene would present in pulmonary lesions of patients with NTM pulmonary infection. Formalin-fixed and paraffin-embedded (FFPE) tissue blocks of 24 patients with NTM infections treated at the hospital from 1998 to 2008 were included. Mycobacterial hsp65 gene was amplified in 20 of the 24 patients, and the species identified by sequencing was consistent with corresponding culture results in 12 of these patients. MTB-specific IS6110 gene was detected in 3 of the 7 patients who had old TB and a subsequent diagnosis of fibrocavitary NTM lung disease. Polymerase chain reaction (PCR) analysis of hsp65 gene also confirmed the presence of MTB genes in 2 of these 3 patients. Our results indicate that PCR amplification and sequencing of the mycobacterial hsp65 gene is a sensitive assay for identification of NTM species in FFPE materials. However, consistent results of PCR analysis, microbiology study, histologic manifestations, radiology, and clinical presentation are important for correct diagnosis of NTM pulmonary infection. The presence of MTB gene in patients with fibrocavitary NTM lung lesions poses a clinical dilemma for deciding concurrent treatment TB and NTM infection.

Respiratory Review of 2009: Nontuberculous Mycobacterium

As the prevalence of tuberculosis declines, the proportion of nontuberculous mycobacterial (NTM) lung disease is increasing in Korea. The combined use of liquid and solid media increases the sensitivity of mycobacterial culture and shortens culture time. Because NTMs are ubiquitous in the environment, NTM lung disease requires strict diagnostic criteria to prevent over-diagnosis of NTM lung disease. Mycobacterium avium complex is the most common pathogen of NTM lung disease in Korea and present in two forms: upper lobe cavitary and nodular bronchiectatic form. Decision of treatment of NTM lung disease depends on the infecting species and overall condition of the patient. Because medical therapy requires the use of multiple drugs over 18 to 24 months, surgery for localized disease may be useful for those species refractory to medical therapy.

Detection of Mycobacterium tuberculosis DNA by PCR in Peripheral Blood of Patients with Pulmonary Tuberculosis

Background: Although pulmonary tuberculosis (TB) is a respiratory disease, the presence of Mycobacterium tuberculosis (Mtb) DNA or Mtb itself has been reported in the peripheral blood (PB) of several patients with pulmonary TB. Additionally, it was recently announced that active pulmona ry TB patients donated PB, and that this blood was then transfused to other individuals in Korea. Methods: Sixty-nine patients with bacteriologically-confirmed pulmonary TB (35), non-tuberculous mycobacterial (NTM) lung disease (6), and other lung diseases (28) were enrolled in this study, which was conducted to determine if Mtb DNA could be detected in the PB by PCR. In addition, 10 pulmonary TB patients with high-burden bacilli were also enrolled in this study for the culture of Mtb in PB. Results: PCR detected the presence of Mtb in 22.8% (8/35) of the pulmonary TB patients, in 16.7% (1/6) of the patients with NTM lung disease, and in none of the patients with other diseases (0%). In addition, no Mtb was cultured from the PB of the 10 pulmonary TB patients. Conclusion: Although Mtb DNA was detected in the PB of some patients with pulmonary TB, viable Mtb was not isolated from the PB of those patients, which indicates that pa tients that viable Mth may not be transmitted via trasfusion of blood of pulmonary TB patients. (Tuberc Respir Dis 2007; 63: 331-336)