Opinions differ by expertise in Mycobacterium avium complex disease

Preliminary Observations of Veterans Without HIV Who Have Mycobacterium avium Complex Pulmonary Disease

Background

Nontuberculous Mycobacterium-related pulmonary disease (NTM-PD) is commonly caused by Mycobacterium avium complex (MAC) and is increasingly recognized in veterans. NTM-PD carries an increased risk of mortality, and lack of treatment is an predictor of increased mortality.

Methods

We describe the clinical characteristics of veterans diagnosed with MAC-pulmonary disease (MAC-PD) followed in a health care setting with varying treatment practices. We reviewed the electronic health records of veterans without HIV who had sputum culture-positive MAC-PD followed at the Jesse Brown Veteran Affairs Medical Center in Chicago, Illinois.

Results

We identified 19 veterans diagnosed with MAC-PD between 2008 and 2019. They were predominantly male (89.5%), Black (73.6%), and had a median age of 74 years. Sixteen veterans (84.2%) had underlying lung disease, and 16 (84.2%) were current or former smokers. Respiratory symptoms were reported in 17 veterans (89.5%). Guideline-directed combination antimycobacterial therapy was initiated in 10 veterans (52.6%); however, only 5 (50.0%) completed treatment. Comorbidities, symptoms, and findings on chest imaging at diagnosis were similar among treated and untreated veterans.

Conclusions

Clinical, imaging, and treatment attributes of MAC-PD in veterans without HIV who reside in metropolitan Chicago are heterogeneous and are associated with a relatively high mortality rate. Further studies are warranted to characterize MAC-PD and its treatment in veterans without HIV who reside in underresourced urban communities in the US.

Non-tuberculous mycobacterial lung disease in patients with bronchiectasis: perceived risk, severity and guideline adherence in a European physician survey

Background

Patients with bronchiectasis are at increased risk of developing non-tuberculous mycobacteria lung disease (NTM-LD), and published guidelines recommend regular testing for NTM infection in this patient population.

Objective

This study aimed to survey physicians managing patients with bronchiectasis to understand the perceived risk of NTM to their patients, perceived disease severity and frequency of testing for NTM.

Methods

The study comprised an online survey of hospital-based physicians in the UK, Germany, Italy, France and the Netherlands. The target group were hospital-based physicians who had managed at least 10 adult patients with bronchiectasis over the preceding 12 months.

Results

In total, 280 physicians completed the survey. Most (87%) thought their patients to be at particular risk of NTM, although it was perceived as a moderate risk versus other respiratory pathogens. Most perceived NTM-LD to impact patient morbidity (84%), and 61% indicated that NTM-LD significantly impacted mortality. 68% of all respondents did not test for NTM prior to initiating macrolide monotherapy, despite guidelines recommending testing. The perceived risk of and screening for NTM varied among countries.

Conclusions

The study demonstrates that physicians understand the risk of NTM-LD and associated morbidity in patients with bronchiectasis; however, a minority do not perceive that NTM-LD significantly affects mortality. Greater awareness of the need to test for NTM infection before initiating macrolide monotherapy for bronchiectasis is essential due to potential emergence of drug-resistant NTM.

Clinical relevance of non-tuberculous mycobacteria isolated from respiratory specimens: seven year experience in a UK hospital

The frequency of isolation of non-tuberculous mycobacteria (NTM) species from respiratory specimens is increasing, however the clinical relevance of such identifications vary by mycobacterial species and geographical location. A retrospective study of 853 NTM isolates from respiratory samples from 386 patients over seven years was performed. Clinical records and radiographic information were examined. Clinical significance was assessed by American Thoracic Society diagnostic criteria. 25% of all patients with respiratory isolates met criteria for non-tuberculous mycobacterial pulmonary disease (NTM-PD). Significant symptoms were weight loss, fever, night sweats, productive cough and haemoptysis. HIV co-infection was a significant risk factor for disease. Cavities, nodules and tree-in-bud were significant radiographic findings. Mycobacterium avium complex (MAC) were the dominant species isolated from this patient cohort. Mycobacterium abscessus (M. abscessus) was the species most likely to cause clinically significant disease and be sputum smear positive, thus warranting particular attention.

Hospital-based antibiotic use in patients with Mycobacterium avium complex

Treatment guidelines exist for pulmonary Mycobacterium avium complex (MAC) infection, although studies suggest poor concordance in clinician practice. Using a national database including hospital encounters of laboratory-confirmed MAC patients, we sought to characterise US treatment practices.

We assessed patients in the Premier Healthcare Database from 2009 to 2013 with two or more MAC-positive cultures or one MAC-positive culture and the International Classification of Diseases (9th revision) code for pulmonary nontuberculous mycobacteria (PNTM). Treatment was characterised by patient-, provider- and facility-level factors; significant differences were assessed (p<0.05). Multilevel Poisson regression estimated adjusted relative risks (aRR) of receiving guidelines-based or macrolide resistance-promoting regimens.

Of 1326 MAC patients, 645 (49%) received treatment: 10% received guidelines-based treatment and 18% resistance-associated therapy. Patients were more likely to receive guidelines-based therapy if they had multiple hospital encounters (aRR 1.5), codes for PNTM (aRR 5.7) or tuberculosis (aRR 4.5) or radiological procedures (aRR 10.9); multiple hospital encounters (aRR 0.8) or a tuberculosis code (aRR 0.1) were less likely to be associated with receiving resistance-promoting regimens.

In hospital-based MAC patients, half received antibiotics active against MAC, a low proportion received therapy based on MAC guidelines and many received antibiotics that promote macrolide resistance. Improved implementation of guidelines-based treatment is needed to decrease use of regimens associated with macrolide resistance.

Few MAC patients receive recommended therapy and improved treatment is needed to prevent resistancehttp://ow.ly/4F0S30lIihn

Meta-analyses and the evidence base for microbial outcomes in the treatment of pulmonary Mycobacterium avium-intracellulare complex disease

Objectives

To perform a systematic review and meta-analysis of the level of funding support and the sputum culture conversion rates in pulmonary Mycobacterium avium-intracellulare complex (P-MAC) disease in adult patients without cystic fibrosis or HIV infection, treated with recommended antibiotic regimens.

Methods

We performed a literature search to identify clinical trials, prospective studies and registries that reported outcomes in P-MAC patients. Studies that reported P-MAC diagnosis and treatments based on established guidelines met the inclusion criteria and were examined for bias and quality. We modified existing quality scales and came up with a 10 star quality score. Outcomes meta-analysed were sputum conversion incidence ratios (IR) and their 95% CI, weighted for study quality.

Results

Twenty-one studies that examined 28 regimens, including 2534 patients in intent-to-treat analyses and 1968 in per-protocol analyses, were identified. The study quality mean ± SD scores were 5.4 ± 2.2 out of 10 stars. Only two (9.5%) studies received public funding. There was significant heterogeneity of microbial effect among treatment regimens (I2 > 40%; P > 0.001). The pooled IR for sustained sputum conversion was 0.54 (95% CI 0.45-0.63) for macrolide-containing regimens versus 0.38 (0.25-0.52) with macrolide-free regimens. Prolonging therapy duration beyond 12 months was associated with an average decline in sputum conversion to 22% (95% CI 1%-44%).

Conclusions

Researchers working on P-MAC therapy have received very little public funding support. As a result, the evidence base for treatment guidelines is based on studies of relatively small numbers of patients in low-quality studies. Nevertheless, these studies showed poor sputum conversion rates in patients receiving recommended treatment regimens.

Diagnosis and Treatment of Nontuberculous Mycobacterial Lung Disease: Clinicians' Perspectives

Nontuberculous mycobacteria (NTM) are emerging pathogens that affect both immunocompromised and immunocompetent patients. The incidence and prevalence of NTM lung disease are increasing worldwide and rapidly becoming a major public health problem. For the diagnosis of NTM lung disease, patients suspected to have NTM lung disease are required to meet all clinical and microbiologic criteria. The development of molecular methods allows the characterization of new species and NTM identification at a subspecies level. Even after the identification of NTM species from respiratory specimens, clinicians should consider the clinical significance of such findings. Besides the limited options, treatment is lengthy and varies by species, and therefore a challenge. Treatment may be complicated by potential toxicity with discouraging outcomes. The decision to start treatment for NTM lung disease is not easy and requires careful individualized analysis of risks and benefits. Clinicians should be alert to those unique aspects of NTM lung disease concerning diagnosis with advanced molecular methods and treatment with limited options. Current recommendations and recent advances for diagnosis and treatment of NTM lung disease are summarized in this article.

Antibiotic treatment for nontuberculous mycobacterial lung disease

Pulmonary infections are the most frequent diseases caused by nontuberculous mycobacteria (NTM). Common causative organisms of pulmonary infection are slowly growing mycobacteria including Mycobacterium avium complex and Mycobacterium kansasii, and rapidly growing mycobacteria including Mycobacterium abscessus complex. Clinical concern has been raised over the increasing incidence of NTM lung disease combined with the poor treatment outcomes of these chronic infectious diseases. Since treatment guidelines of the American Thoracic Society/Infectious Disease Society of America were published in 2007 there have been continuous efforts to improve the outcomes of NTM lung disease, albeit slowly and with limitations. Here, we focus on recent advances in the antibiotic treatment of NTM lung disease.

Retrospective study of the predictors of mortality and radiographic deterioration in 782 patients with nodular/bronchiectatic Mycobacterium avium complex lung disease

OBJECTIVES

Some patients with nodular/bronchiectatic Mycobacterium avium complex lung disease (NB MAC-LD) deteriorate and die. The main aim of the study is to evaluate the prognostic factors and radiographic outcomes in patients with NB MAC-LD.

SETTING

Retrospective single-centre review.

PARTICIPANTS

782 HIV-negative patients with NB MAC-LD treated at our institution in Japan.

PRIMARY AND SECONDARY OUTCOME MEASURES

All-cause and MAC-LD progression mortality rates and the prognostic factors, and radiographic deterioration rates and the prognostic factors.

RESULTS

Mean age was 68.1 years, and median follow-up period was 4.3 years. Death from any cause and progression of MAC lung disease (MAC-LD) occurred in 130 (16.6%), and 19 (2.4%) patients, respectively. All-cause and MAC-LD progression 10-year mortality rates were 27.4% and 4.8%, respectively. In 536 patients with MAC-LD who were followed-up for more than 1 year, radiographic deterioration occurred in 221 (41.2%) patients and median time-to-radiographic deterioration was 9 years. A multivariate Cox proportional hazard model showed male sex, older age, body mass index <18.5 kg/m(2), absence of bloody sputum, hypoalbuminaemia and erythrocyte sedimentation rate >40 mm/h to be negative prognostic factors for all-cause mortality, and the presence of idiopathic pulmonary fibrosis, haemoglobin <11.3 mg/dL, C reactive protein >1.0 mg/dL and the presence of cavity to be negative prognostic factors for radiographic deterioration.

CONCLUSIONS

Only 2.4% of patients with NB MAC-LD died from MAC-LD progression. As clinical trials testing the effectiveness of drug therapy in patients with NB MAC-LD are being designed and implemented, the primary end point could be time-to-radiographic deterioration, and trial patients need to be stratified according to these prognostic factors before randomisation.

The Challenge of Pulmonary Nontuberculous Mycobacterial Infection

The incidence of nontuberculous mycobacterial (NTM) lung disease is increasing. Current treatment strategies are largely based on expert opinion. The lack of randomized clinical trials to inform treatment leave clinicians with many questions regarding the most effective and safe regimens. The risk-benefit ratio of therapy is often thought to favor observation given the chronic nature of the disease, multiple long-term antibiotics recommended for therapy, side effects associated with treatment, and perceived lack of efficacious therapies.