Nontuberculous mycobacterial pulmonary disease and Aspergillus co-infection: Bonnie and Clyde?

Circulatory Inflammatory Proteins as Early Diagnostic Biomarkers for Invasive Aspergillosis in Patients with Hematologic Malignancies-an Exploratory Study

OBJECTIVES

Invasive aspergillosis (IA) is a major cause of mortality in immunocompromised patients and it is difficult to diagnose because of the lack of reliable highly sensitive diagnostics. We aimed to identify circulating immunological markers that could be useful for an early diagnosis of IA.

METHODS

We collected longitudinally serum samples from 33 cases with probable/proven IA and two matched control cohorts without IA (one with microbiological and clinical evidence of bacterial or viral non-fungal pneumonia and one without evidence of infection, all matched for neutropenia, primary underlying disease, and receipt of corticosteroids/other immunosuppressants) at a tertiary university hospital. In addition, samples from an independent cohort (n = 20 cases of proven/probable IA and 20 matched controls without infection) were obtained. A panel of 92 circulating proteins involved in inflammation was measured by proximity extension assay. A random forest model was used to predict the development of IA using biomarkers measured before diagnosis.

RESULTS

While no significant differences were observed between IA cases and infected controls, concentrations of 30 inflammatory biomarkers were different between cases and non-infected controls, of which nine were independently replicated: PD-L1, MMP-10, Interleukin(IL)-10, IL-15RA, IL-18, IL-18R1, CDCP1, CCL19 and IL-17C. From the differential abundance analysis of serum samples collected more than 10 days before diagnosis and at diagnosis, increased IL-17C concentrations in IA patients were replicated in the independent cohort.

CONCLUSIONS

An increased circulating concentration of IL-17C was detected both in the discovery and independent cohort, both at the time of diagnosis and in samples 10 days before the diagnosis of IA, suggesting it should be evaluated further as potential (early) biomarker of infection.

Treatment of the Less Common Nontuberculous Mycobacterial Pulmonary Disease

Nontuberculous mycobacterial pulmonary disease caused by the less common nontuberculous mycobacteria have distinct features depending on the species. Diagnostic evaluation follows the established criteria for all nontuberculous mycobacteria, but with certain qualifications given species-specific and regional differences in pathogenicity. Clinicians should first institute nonpharmacologic management and evaluate clinical, radiologic, and microbiologic factors in the decision regarding antimycobacterial therapy. Treatment is challenging, and evidence-based recommendations are limited for most species. Drug susceptibility testing is used to help with regimen selection; however, this approach is imperfect given the uncertain correlation between in vitro activity and clinical response for most drugs.

Epidemiology and management of nontuberculous mycobacterial disease in people with cystic fibrosis, the Netherlands

BACKGROUND

Nontuberculous mycobacteria (NTM) are opportunistic, difficult to treat pathogens. With increasing prevalence of NTM infections in people with cystic fibrosis (pwCF) and the improved life expectancy, the burden is expected to grow.

METHODS

We assessed the epidemiology and management of NTM isolation and disease in pwCF in the Netherlands using a survey and retrospective, case-controlled data from the Dutch CF Registry. We determined the isolation prevalence, treatment and outcomes from 2013-2019.

RESULTS

NTM isolation prevalence increased from 1.0% to 3.6% (2013-2019). This was a single NTM isolation in 53.7% of the adults and 60.0% of the children. M. abscessus and M. avium complex (MAC) were most frequent (47.1 and 30.9%). Of the treated pwCF, 48.5% attained culture conversion of M. abscessus; 54.5% for MAC. Children with an NTM isolation showed more infections with S. maltophilia and/or A. fumigatus (p < 0.001) compared to controls. In the year prior to NTM isolation, children in the NTM group had a lower mean FEV1% predicted (81.5 ± 16.7 vs. 88.6 ± 15.3, p = 0.024), while adults in the NTM group had more IV antibiotic days compared to controls (60 vs. 17, p = 0.047). In the following years, FEV1% predicted declined faster in pwCF with NTM than the control group (children: -3.8% vs. -1.6%, p = 0.023; adults: -0.7% and 0.4%, ns).

CONCLUSIONS

The isolation prevalence of 3.6%, poor treatment outcomes and associated lung function decline emphasize that NTM pulmonary disease (NTM-PD) is a significant health issue among pwCF in the Netherlands. Its prevention and treatment require increased attention.

Clinical features and treatment outcomes of pulmonary Mycobacterium avium-intracellulare complex with and without co-infections

Coinfections are more common in patients with cystic fibrosis and bronchiectasis. Infiltrates on imaging studies are seen more commonly in patients with coinfections, but coinfections did not affect treatment outcomes of pulmonary Mycobacterium avium complex.

Case studies to illustrate good practice in the management of non-tuberculous mycobacterial pulmonary disease

Pulmonary disease caused by non-tuberculous mycobacteria (NTM-PD) can be a complex condition for health care providers to manage, and delayed diagnosis and treatment failure are common. Here we present three case studies that illustrate key challenges in the diagnosis and treatment of NTM-PD, and provide guidance on these issues. In addition, we make recommendations on how the overall management of NTM-PD may be improved, through strategies such as physician education to recognise NTM-PD, and the development of multidisciplinary teams and patient-support groups.

Clinical Features, Diagnostic Test Performance, and Prognosis in Different Subtypes of Chronic Pulmonary Aspergillosis

Objective

The aim of this study was to describe clinical features in different subtypes of chronic pulmonary aspergillosis (CPA)-simple aspergilloma (SA), chronic cavitary pulmonary aspergillosis (CCPA), chronic fibrosing pulmonary aspergillosis (CFPA), aspergillus nodule (AN), and subacute invasive aspergillosis (SAIA), respectively, and identify long-term prognosis of CPA.

Methods

We reviewed patients diagnosed with different subtypes of CPA from 2002 to 2020 at Nanjing Jinling Hospital, China. We analyzed the clinical and survival information of five different subgroups. A Cox regression model was used to explore proper antifungal duration and long-term survival factors of CCPA and SAIA.

Results

A total of 147 patients with CPA were included, consisting of 11 SA, 48 CCPA, 5 CFPA, 12 AN, and 71 SAIA. The most common underlying pulmonary disease was pulmonary tuberculosis (n = 49, 33%), followed by bronchiectasis (n = 46, 31.3%) and chronic obstructive pulmonary disease (COPD) or emphysema (n = 45, 30.6%), while in SAIA and CFPA groups, the most common was COPD or emphysema (45.1 and 100%). Cough (85%), expectoration (70.7%), hemoptysis (54.4%), and fever (29.9%) were common symptoms, especially in CCPA, CFPA, and SAIA groups. The common imaging manifestations included cavitation (n = 94, 63.9%), fungal ball (n = 54, 36.7%), pleural thickening (n = 47, 32.0%), and bronchiectasis (n = 46, 31.3%). SAIA and CFPA groups had a lower value of hemoglobin (HB) and serum albumin (ALB) with higher C-reactive protein and erythrocyte sedimentation rate. The positive rate of sputum culture, serum galactomannan (GM), and bronchoalveolar lavage fluid GM was 32.7% (36/110), 18.4% (18/98), and 48.7% (19/39), respectively. There were 64.6% (31/48) patients with CCPA and 25.4% (18/71) patients with SAIA who received surgery and the 5-year cumulative survival rate was 92.1 and 66.6%, respectively. SAIA, old age, male, low body mass index (BMI), COPD or emphysema, multiple distribution, low serum ALB, and positive sputum culture were adverse prognosis factors for SAIA and CCPA group, and BMI ≤ 20.0 kg/m² was independently associated with increased mortality (hazard ratio (HR) 5.311, 95% CI 1.405–20.068, p = 0.014). Multivariable Cox regression indicated that surgery (HR 0.093, 95% CI 0.011–0.814, p = 0.032) and antifungal duration >6 months (HR 0.204, 95% CI 0.060–0.696 p = 0.011) were related to improved survival.

Conclusion

The clinical features and laboratory test performance are different among SA, CCPA, CFPA, AN, and SAIA. Low BMI was an independent risk factor for survival. Selective surgery and antifungal duration over 6 months were associated with improved survival.

Aspergillus-related lung disease in people with cystic fibrosis: can imaging help us to diagnose disease?

In people with cystic fibrosis (PwCF), viscous sputum and dysfunction of the mucociliary escalator leads to early and chronic infections. The prevalence of Aspergillus fumigatus in sputum is high in PwCF and the contribution of A. fumigatus to the progression of structural lung disease has been reported. However, overall, relatively little is known about the contribution of A. fumigatus to CF lung disease. More knowledge is needed to aid clinical decisions on whether to start antifungal treatment. In this review, we give an overview of A. fumigatus colonisation and infection in PwCF and the different types of pulmonary disease caused by it. Furthermore, we discuss the current evidence for structural lung damage associated with A. fumigatus in PwCF on chest computed tomography and magnetic resonance imaging. We conclude that radiological outcomes to identify disease caused by A. fumigatus can be important for clinical studies and management.

Impact of treatment duration on recurrence of chronic pulmonary aspergillosis

OBJECTIVES

Limited data exist on the optimal treatment duration for chronic pulmonary aspergillosis (CPA). We investigated the treatment outcome and recurrence rate according to treatment duration in CPA patients.

METHODS

A total of 196 patients who completed at least 6 months of antifungal therapy (99% oral itraconazole) and achieved favorable treatment responses were analyzed. A Cox's proportional hazards regression model was used to adjust for potential confounding factors in the association between the duration of antifungal therapy (6-12 months vs. ≥ 12 months) and recurrence.

RESULTS

All patients were treated with antifungal agents for at least 6 months (median: 12.5, interquartile range: 8.5-18.4 months) and categorized into 6-12 months group (79/196, 40%) and ≥ 12 months group (117/196, 60%). The 6-12 months group had significantly higher recurrence rates owing to CPA aggravation after the completion of treatment compared with the ≥ 12 months group (51% vs. 25%, P  =  0.003). In a Cox's proportional hazards regression model, treatment duration ≥ 12 months was independently associated with a lower risk of recurrence (adjusted hazard ratio: 0.48, 95% confidence interval: 0.28-0.80).

CONCLUSIONS

Our data suggest that prolonging antifungal therapy beyond 12 months could reduce the recurrence rate in CPA patients.

Aspergillus isolation in nontuberculous mycobacterial pulmonary disease: Associated with antimycobacterial treatment initiation but not response

PURPOSE

Chronic pulmonary aspergillosis is a serious complication of nontuberculous mycobacterial pulmonary disease (NTM-PD), and diagnosis remains challenging. The present study examined associations between the respiratory isolation of Aspergillus and the clinical characteristics and treatment outcomes of patients with NTM-PD.

METHODS

All patients meeting NTM-PD criteria as defined by the ATS/IDSA statement, with at least one respiratory sample cultured for fungi, were included in this retrospective cohort analysis. Patients with at least one respiratory sample isolating Aspergillus were compared to patients who did not isolate Aspergillus. The primary outcomes were culture conversion and radiologic evolution 12 months after NTM-PD treatment initiation.

RESULTS

During a 12 year period, 497 patients meeting the inclusion criteria were seen in our tertiary care center, of whom 130 grew Aspergillus. Median follow up after NTM-PD diagnosis was 46 months. Inhaled corticosteroid use, a nodular-bronchiectatic CT pattern and NTM-PD treatment initiation were more frequent in patients who isolated Aspergillus compared to those who did not (p-value respectively 0.01, 0.03 and < 0.001). Rates of culture conversion (63.0% vs. 62.2%, respectively; p-value 1) and radiologic evolution (improvement or stability in 69.7% vs. 77.2%, respectively; p-value 0.25) were not significantly different between treatment groups. Likewise, culture reversion rate and 5-year mortality were not significantly different. Additionally, A. fumigatus and repeated detection of Aspergillus were not associated with treatment outcomes.

CONCLUSION

There was no association between respiratory isolation of Aspergillus and NTM-PD treatment outcomes in this cohort. However, treatment for NTM-PD was initiated more frequently in patients who isolated Aspergillus.

Non-tuberculous mycobacterial infections-A neglected and emerging problem

Non-tuberculous mycobacteria (NTM) are ubiquitous dwellers of environmental niches and are an established cause of natural and nosocomial infections. The incidence of NTM infections is rising owing to a growing population of immunocompromised and vulnerable individuals, complex medical and surgical procedures, as well as increased awareness and diagnostic capabilities. The prevalence of different NTM varies between continents, regions, and countries. The true global burden of pulmonary and extrapulmonary disease is unknown and estimates are subject to under and/or over-estimation. Diagnosis requires confirmation by isolation of NTM along with clinical and radiological criteria, which may be suboptimal at all levels. Susceptibility testing is complex and clinical breakpoints are not available for many of the drugs. Frequently, NTM infections are not considered until late in the course of disease. Improved and rapid detection of tuberculosis cases in high-burden countries has, however, also brought NTM infections into the limelight, and has identified a need for research efforts towards rapid diagnostic tests and the identification of biomarkers to monitor the treatment response in patients with NTM infections.

Clinical relevance of pulmonary non-tuberculous mycobacterial isolates in three reference centres in Belgium: a multicentre retrospective analysis

Background/objectives

Assessing the clinical relevance of non-tuberculous mycobacteria (NTM) isolated from respiratory samples can be challenging. The epidemiology and pathogenicity of NTM species vary geographically. We aimed to outline the clinical relevance and associated radiological patterns of NTM species isolated in Belgium.

Methods

We performed a retrospective multicentre analysis of all patients identified from the laboratory database with > 1 respiratory sample growing NTM from January 2010 through December 2017. We collected clinical, radiological and microbiological data through medical record review and assessed clinical relevance according to ATS/IDSA criteria for NTM pulmonary disease (NTM-PD).

Results

Of the 384 unique patients, 60% were male, 56% had a smoking history and 61% had pre-existing lung disease. Mycobacterium avium complex (MAC), M. gordonae and M. xenopi were the most frequently isolated species: 53, 15 and 8% respectively. 43% of patients met ATS/IDSA criteria, of whom 28% presented with fibrocavitary disease. Weight loss, fever, nodular bronchiectatic and fibrocavitary lesions on chest CT, and a positive acid-fast bacilli (AFB) stain were significantly associated with NTM-PD. The species with the highest pathogenic potential were M. abscessus (11/12), M. malmoense (6/7) and M. intracellulare (41/64).

Conclusion

In our study, MAC was the most commonly isolated NTM species, but M. abscessus and M. malmoense showed the highest probability of being clinically relevant. Clinical relevance varied not only by species but also by radiological findings on chest CT and AFB staining. Clinicians should consider these elements in their treatment decision making. Prospective data including clinical outcome are needed to provide more robust evidence.