Performance of Interferon-Gamma Release Assays in the Diagnosis of Nontuberculous Mycobacterial Diseases-A Retrospective Survey From 2011 to 2019

Stealth in non-tuberculous mycobacteria: clever challengers to the immune system

Non-tuberculous Mycobacteria (NTM) are found extensively in various environments, yet most are non-pathogenic. Only a limited number of these organisms can cause various infections, including those affecting the lungs, skin, and central nervous system, particularly when the host's autoimmune function is compromised. Among these, Non-tuberculous Mycobacteria Pulmonary Diseases (NTM-PD) are the most prevalent. Currently, there is a lack of effective treatments and preventive measures for NTM infections. This article aims to deepen the comprehension of the pathogenic mechanisms linked to NTM and to formulate new intervention strategies by synthesizing current research and detailing the different tactics used by NTM to avoid elimination by the host's immune response. These intricate mechanisms not only affect the innate immune response but also successfully oppose the adaptive immune response, establishing persistent infections within the host. This includes effects on the functions of macrophages, neutrophils, dendritic cells, and T lymphocytes, as well as modulation of cytokine production. The article particularly emphasizes the survival strategies of NTM within macrophages, such as inhibiting phagosome maturation and acidification, resisting intracellular killing mechanisms, and interfering with autophagy and cell death pathways. This review aims to deepen the understanding of NTM's immune evasion mechanisms, thereby facilitating efforts to inhibit its proliferation and spread within the host, ultimately providing new methods and strategies for NTM-related treatments.

Adjunctive Diagnosis of Mycobacterium gordonae Pneumonia by Metagenomic Next-Generation Sequencing in an Immunocompetent Patient: A Case Report and Literature Review

Introduction

Mycobacterium gordonae is a nonpathogenic pathogen commonly found in nature and is generally considered a contaminant in clinical practice. Although there have been few reported cases of infection, most of them are secondary to immunosuppression. This paper described a rare case of globular shadow in the chest of an immunocompetent male who was diagnosed with M. gordonae pulmonary disease. He went to the hospital with chest pains that had lasted for more than two weeks. The routine clinical pathogen detection failed to discover the cause of the infection. Although metagenomic next-generation sequencing (mNGS) of the lung tissue was negative, M. gordonae was detected in the background microorganism with only one read. Based on the pathological results, it was considered to be the causative pathogen. Two months of treatment with rifampicin, ethambutol, clarithromycin, and levofloxacin resulted in significant reduction and absorption of lung lesions. No abnormalities were detected in either lung one year later. The lack of positive culture and other conventional microbiological test results make this case is not a strictly confirmed case. This study also explored the clinical features and treatment options of 32 cases of M. gordonae pulmonary disease through a systematic review of the literature. Although there is no standard recommended treatment regimen for M. gordonae infection, but combination therapy with macrolides, rifampicin, and ethambutol has been proven effective.

Conclusion

This case highlights that when the clinical highly suspected of infection, mNGS can contribute to the early identification of non-tuberculous Mycobacterium (NTM) even with low reads, when clinical suspicion is high. Analyzing background microorganisms in sterile samples may help diagnose rare pathogens.

Low performance of interferon gamma release assay Quantiferon-TB gold coupled or not with Pst1/3/lipoglycan humoral detection to predict Mycobacterium tuberculosis complex disease in a low-burden area

Whole T cell interferon gamma release assays such as QuantiFERON-TB Gold Plus (QTF-TB) are used to evaluate Mycobacterium tuberculosis complex (MTC) exposure but fail to discriminate latent tuberculosis infection (LTBI) from active disease. In this study conducted in a low-burden area, 1215 patients presenting MTC risk and tested both for QTF-TB and mycobacterial infection (microscopy, culture, and/or PCR) were selected, as well as 1298 controls screened with QTF-TB before medical recruitment. The humoral response (LIODetect®TB-ST) was further evaluated in 199 selected patients. In patients with active disease, MTC positivity (culture and/or PCR with species identification) was associated with QTF-TB positivity (45/56, 80.4 %). Although QTF-TB1/TB2 peptides were not suitable for discriminating against active MTC disease from LTBI, the cut-off value of 4.4 IFN-γ IU/mL produced the best diagnostic performance for MTC detection. Lower levels of QTF-TB were reported among patients with isolated active pulmonary MTC as compared to a lymph-nodal location and a disseminated form. Next, antibodies were detected in 4/55 (7.3 %) active MTC disease cases, while negative in cases of LTBI and indeterminate/negative QTF-TB. In conclusion, the added value to combine cellular (QTF-TB) and humoral (LIODetect®TB-ST) assays to predict an active MTC disease is limited.

A narrative review of nontuberculous mycobacterial pulmonary disease: microbiology, epidemiology, diagnosis, and management challenges

INTRODUCTION

Nontuberculous mycobacteria (NTM) are a diverse group of mycobacterial species that are ubiquitous in the environment. They are opportunistic pathogens that can cause a range of diseases, especially in individuals with underlying structural lung disease or compromised immune systems.

AREAS COVERED

This paper provides an in-depth analysis of NTM infections, including microbiology, environmental sources and transmission pathways, risk factors for disease, epidemiology, clinical manifestations and diagnostic approaches, guideline-based treatment recommendations, drugs under development, and management challenges.

EXPERT OPINION

Future approaches to the management of NTM pulmonary disease will require therapies that are well tolerated, can be taken for a shorter time period and perhaps less frequently, have few drug-drug interactions, and are active against the various strains of pathogens. As the numbers of infections increase, such therapies will be welcomed by clinicians and patients.

Rapid diagnosis of non-tuberculous mycobacterial pulmonary diseases by metagenomic next-generation sequencing in non-referral hospitals

Objectives

The incidence of non-tuberculous mycobacterial pulmonary disease (NTM-PD) has increased steadily globally, but the current culture-based diagnosis of NTM-PD is difficult and time-consuming, leading to a high possibility of misdiagnosis. Therefore, new methods should be introduced to improve the processes for clinical diagnosis of this disease.

Methods

Our retrospective observational study enrolled 12 NTM-PD patients who were identified by way of metagenomic next-generation sequencing (mNGS), as well as the characteristic radiological presentation of slowly progressed, usually concomitant bronchiectasis, small cavitary opacity, and multiple nodules that respond poorly to empirical antibiotic therapy. These patients received the recommended drug regimen based on the identified non-tuberculous mycobacteria (NTM) species. Clinical data, including symptoms, laboratory tests, dynamic computed tomography imaging, treatment, and outcome, were recorded and analyzed.

Results

The results of mNGS were all positive, with the standard specifically mapped read numbers (SDSMRN) of NTM ranging from 1 to 766; this was confirmed in six patients via quantitative polymerase chain reaction (qPCR) analysis. The duration fromsample collection tomNGS results was 1-4 days. Among our 12 patients (except for one lost to follow-up) the CT imaging for 11 patients showed significant absorption of lesions.

Conclusions

Our results draw attention to NTM infection as a possible cause of community-acquired pneumonia, especially in patients with suggestive radiological presentation and poor responses to empirical antibiotic therapy. Our study also indicated that mNGS represented a potentially effective tool for the rapid identification of NTM in the respiratory sample. Improved clinician awareness combined with the utilization of mNGS could guide earlier diagnosis and targeted treatment, and finally improved the prognoses of patients with NTM-PD.

Performance of Interferon-γ Release Assays in Patients with Mycobacterium kansasii Infection

Objective

To evaluate the performance of interferon-γ release assays (IGRAs) in patients with Mycobacterium kansasii infection.

Methods

Consecutive patients between May 2012 and June 2021 who had positive for mycobacterial cultures and who underwent IGRAs (T-SPOT.TB or QuantiFERON-TB Gold [QFT-G]) were included in the analysis. The IGRA positivity rates among patients with M. kansasii isolates were then calculated. If M. kansasii was identified in at least two sputum samples or in sterile samples, M. kansasii disease was then diagnosed. Otherwise, colonisation was considered.

Results

During the study period, 54 patients with M. kansasii infection underwent T-SPOT.TB (n=48) or QFT-G (n=6) assays. The mean age was 44.1±13.4 years, 85.2% (46/54) were male. Eight patients were diagnosed with M. kansasii disease and another 46 patients were considered to have colonisation. Twenty-four patients (T-SPOT.TB, n=23; QFT-G, n=1) were positive for IGRAs, for an overall rate of 44.4% (24/54; T-SPOT.TB, 47.9% [23/48]; QFT-G, 16.7% [1/6]) for IGRAs, 25.0% (2/8) for M. kansasii disease, and 47.8% (22/46) for colonisation.

Conclusion

Positive IGRA rates were relatively low in patients with M. kansasii infection. More efforts are required to improve the performance of IGRAs in diagnosing M. kansasii infection.

Mandibular Nodule Caused by Mycobacterium marinum with False Positive Interferon-γ Release Assay. A Case Report

Mycobacterium marinum is a ubiquitous organism inhabiting both fresh and salt water. It can cause human diseases such as skin and soft tissue infection. The organism is also known to cause a false positive reaction to interferon-γ release assay, the test to diagnose latent tuberculosis infection. Here, we present a case of submandibular nodule caused by M. marinum with positive T-SPOT.TB test, which was likely to be false positive.

Peripheral blood indices to predict PFS/OS with anlotinib as a subsequent treatment in advanced small-cell lung cancer

OBJECTIVE

In the phase II ALTER-1202 (NCT03059797) trial, anlotinib significantly improved progression-free survival (PFS) and overall survival (OS) in patients with advanced small-cell lung cancer (SCLC) who underwent at least 2 previous chemotherapy cycles, when compared with a placebo group. To identify potential factors for predicting efficacy and prognosis with anlotinib treatment, we analyzed hematological indices at baseline and adverse events (AEs) over the course of anlotinib treatment.

METHODS

Data were collected from March 2017 to April 2019 from a randomized, double-blind, placebo-controlled, multicenter, phase II trial of anlotinib. Eligible patients were randomly assigned 2:1 to receive anlotinib or placebo until disease progression, intolerable toxicity, or withdrawal of consent. The patients received anlotinib (12 mg) or an analogue capsule (placebo) orally once daily for 14 days every 3 weeks. The hematological indices at baseline and AEs that occurred in the initial 2 treatment cycles were recorded. The Kaplan-Meier test and Cox regression model were used to assess survival differences.

RESULTS

A total of 82 patients (81 patients with complete data) were randomly assigned to receive anlotinib, with 38 receiving a placebo as a control. Multivariate analysis indicated that an elevated neutrophil to lymphocyte ratio > 7.75 and lactate dehydrogenase > 254.65 U/L at baseline were independent risk factors for PFS; basal elevated aspartate aminotransferase > 26.75 U/L, neuron specific enolase > 18.64 ng/mL, and fibrinogen > 4.645 g/L were independent risk factors for OS. During treatment, elevated γ glutamyltransferase and hypophosphatemia were independent predictors for a poor PFS, and elevated γ-glutamyl transferase and hypercholesterolemia were independent factors for OS.

CONCLUSIONS

Our study preliminarily defined potential factors that affected the PFS and OS at baseline and during anlotinib treatment in patients with advanced SCLC. Our findings provide a basis for screening the dominant population and for dynamic efficacy monitoring with anlotinib therapy.

Who Were Hospitalized Deceased Patients from COVID-19 During the First Year of Pandemic? Retrospective Analysis of 1104 Deceased Patients in South of France

Introduction

Following the first year of the COVID-19 pandemic, a complete analysis of the characteristics of the deceased hospitalized patients was performed, to identify factors related to premature mortality and to compare patient profiles according to the epidemic periods.

Methods

Retrospective analysis of 1104 deceased patients in two University Hospitals in South-eastern France, between March 1, 2020 and March 12, 2021 from Hospital’s electronic medical records was performed.

Results

Mean age was 80 years (± 11.1) and 10% of the deceased were younger than 65 years with specific comorbidities, e.g., genetic conditions, metastatic cancer, or massive obesity. Among the three clusters identified, two clusters (75% of deceased patients) include very elderly patients with numerous comorbidities, and differ by their proportion of dependent institutionalized patients. The third cluster is made up of younger patients with fewer but severe comorbidities. Deceased patients’ profiles varied according to the epidemic periods: during the first period (March–June 2020), more patients were institutionalized. The second period (September–December2020) coincided with a higher mortality rate.

Conclusions

This study confirmed that most patients hospitalized and dying from COVID-19 were frail, i.e., elderly and/or highly comorbid and that the small proportion of young patients had severe comorbidities.

Supplementary Information

The online version contains supplementary material available at 10.1007/s44197-022-00039-3.

Case Report: Disseminated Mycobacterium intracellulare Infection With More Than 1-Year Follow-Up in a Young Boy With IFNGR1 Deficiency

All members of the genus Mycobacterium are collectively labeled as "non-tuberculous mycobacterium" (NTM), with the exception of the Mycobacterium tuberculosis complex and M. leprae. Recently, the incidence of NTM infection and number of cases have been increasing, but their identification remains difficult in some countries. Usually, NTM infections and diseases are associated with primary immunodeficiency diseases (PIDs), and their prognoses can be improved with a timely diagnosis and appropriate treatment. Here, we report a case of a 3-year-old boy with disseminated NTM disease (Mycobacterium intracellulare) and interferon-γ receptor 1 (IFNGR1) deficiency. He presented with skin and soft-tissue disease, disseminated osteomyelitis, and pulmonary disease. Initially, we suspected an infection due to the Bacillus Calmette-Guérin vaccine but later suspected Langerhans cell histiocytosis. Following oral treatment of azithromycin, rifampicin, and ethambutol, his condition improved progressively according to clinical and imaging manifestations. This case highlights the importance of early identification of the pathogen in a timely prescription of specific treatments in PIDs patients. We also discuss our experience of treatment of M. intracellulare disease in patients with IFNGR1 deficiency.