Prevalence and predictors of NTM in presumed/confirmed drug-resistant TB.

INTRODUCTION: Non-tuberculous mycobacteria (NTM) are increasingly isolated in individuals with presumed/confirmed pulmonary TB. We aimed to estimate the prevalence and species distribution of NTM among presumed/confirmed drug-resistant TB (DR-TB) individuals and determine NTM isolation predictors. METHODS: Sputum samples collected for DR-TB diagnosis and follow-up from 2012 to 2021 in Ghana were retrospectively analysed. Samples were subjected to sputum smear microscopy (SSM) and mycobacterial culture. The MPT64 assay was performed on positive cultures to distinguish between Mycobacterium tuberculosis complex MTBc and NTM. NTM isolates were re-cultured for species identification using GenoType® Mycobacterium CM/AS line-probe assay, polymerase chain reaction, and Sanger sequencing targeting 16S rRNA and rpoB genes. MTBc isolates identified by GenoType underwent spoligotyping. A logistic regression model was used to identify the predictors of NTM isolation. RESULTS: Of the 2,492 samples, 839 (33.7%) tested culture-positive for mycobacteria, with 257 (30.6%) presumed to be NTM. Of these, 53 (23.6%) were identified at the species level, with a predominance of M. intracellulare (66.0%). MPT64 testing missed 18 (3%) MTBc isolates. Logistic regression showed increased odds of NTM isolation in follow-up samples (aOR 2.41, 95% CI 1.46-3.99). NTM species were isolated from 46 patients, with four classified as NTM pulmonary disease. CONCLUSION: Enhancing our understanding of local NTM epidemiology and improving local diagnostic capabilities can optimise patient management strategies and outcomes.

INTRODUCTION: Les mycobactéries non tuberculeuses (NTM) sont de plus en plus souvent isolées chez les personnes atteintes de TB pulmonaire présumée/confirmée (DR-TB). Notre étude visait à évaluer la fréquence et la répartition des différentes espèces de NTM chez les personnes atteintes de TB pharmacorésistante, ainsi qu'à identifier les facteurs prédictifs de l'isolement de ces NTM. MÉTHODES: Les échantillons d'expectorations collectés entre 2012 et 2021 au Ghana pour le diagnostic et le suivi de la DR-TB ont été analysés rétrospectivement. Les échantillons ont subi une microscopie du frottis d'expectoration (SSM) et une culture mycobactérienne. Le test MPT64 a été réalisé sur les cultures positives pour différencier le complexe Mycobacterium tuberculosis (MTBc) et les NTM. Les isolats de NTM ont été soumis à une nouvelle culture pour identification des espèces à l'aide du test par sondes en ligne GenoType® Mycobacterium CM/AS, de l'amplification en chaîne par polymérase et du séquençage de Sanger ciblant les gènes 16S rRNA et rpoB. Les isolats de MTBc identifiés par GenoType ont été soumis à un spoligotypage. Un modèle de régression logistique a été utilisé pour identifier les facteurs prédictifs de l'isolement des NTM. RÉSULTATS: Parmi les 2 492 échantillons analysés, 839 (33,7%) ont été testés positifs à la culture de mycobactéries, dont 257 (30,6%) étaient présumés être des NTM. Parmi ces échantillons, 53 (23,6%) ont été identifiés au niveau de l'espèce, avec une prédominance de M. intracellulare (66,0%). Le test MPT64 a échoué à détecter 18 (3%) isolats de MTBc. L'analyse de régression logistique a révélé une probabilité accrue d'isolement de MNT dans les échantillons de suivi (aOR 2,41 ; IC à 95% 1,46­3,99). Des espèces de NTM ont été isolées chez 46 patients, dont quatre ont été classés dans la catégorie des maladies pulmonaires à NTM. CONCLUSION: Une connaissance approfondie de l'épidémiologie locale des NTM et le renforcement des compétences de diagnostic au niveau local peuvent améliorer les stratégies de prise en charge des patients et les résultats obtenus.

Exploring the use of exhaled breath as a diagnostic tool for pulmonary TB.

Despite its historical decline, TB remains a significant cause of infectious disease-related global deaths. The lack of reliable diagnostic tests for vulnerable groups, such as children and immunocompromised patients, remains a challenge for TB control. For decades, it has been recognised that exhaled breath has great potential as a non-invasive and universally accessible clinical alternative to sputum and invasive sampling methods. Although translation into clinical practice has not yet occurred, there has been significant progress with promising results in various applications, including diagnosis, estimation of infectiousness, and monitoring of treatment response. More recently, the COVID-19 pandemic reignited global interest in this field and technological advances have further accelerated its development. In the coming decade, breath sampling will enhance our understanding of respiratory infectious diseases and host-immune responses, which may lead to clinical applications. Here we discuss the diagnostic landscape of TB and the current state of the art of breath sampling.

Elevated serum calprotectin (S100A8/A9) in patients with severe asthma.

OBJECTIVE: Asthma is a heterogeneous disease consisting of several inflammatory phenotypes of which neutrophilic asthma is associated with poorer responses to classic therapies, namely (inhaled) corticosteroids. The development of targeted therapies requires the identification of biomarkers to distinguish these phenotypes. Currently, we lack validated biomarkers for non-eosinophilic asthma. The aim of this study is to examine serum calprotectin (SC) in asthmatics and its potential as biomarker for neutrophilic asthma. METHODS: Hundred-seventeen severe asthmatics were referred for sputum induction and data were obtained from their medical records. To evaluate the association between SC and asthma phenotypes, patients were divided into subgroups based on sputum cell count (3% eosinophils and 61% neutrophils). Additionally, SC levels of asthmatics were compared with these of patients with chronic obstructive pulmonary disease, non-cystic fibrosis bronchiectasis and healthy controls. RESULTS: Asthmatics (n = 45) had significantly higher levels of SC than healthy controls. No significant differences were found between the different asthma phenotypes and in comparison with COPD patients. SC was significantly higher in asthmatics with a lower FEV1/FVC ratio (<70) and non-significantly elevated SC levels were seen in asthmatics with frequent exacerbations (>2 in the last year). CONCLUSION: In conclusion, there was no difference in SC levels between the different inflammatory subtypes in asthmatics. Nevertheless, severe asthmatics seemed to have higher SC levels suggesting that SC may be a marker of disease severity rather than a marker for specific inflammatory subtypes in asthmatics. Further research in larger cohorts is necessary to validate SC as biomarker in severe asthmatics.

Monocyte-driven atypical cytokine storm and aberrant neutrophil activation as key mediators of COVID-19 disease severity.

Epidemiological and clinical reports indicate that SARS-CoV-2 virulence hinges upon the triggering of an aberrant host immune response, more so than on direct virus-induced cellular damage. To elucidate the immunopathology underlying COVID-19 severity, we perform cytokine and multiplex immune profiling in COVID-19 patients. We show that hypercytokinemia in COVID-19 differs from the interferon-gamma-driven cytokine storm in macrophage activation syndrome, and is more pronounced in critical versus mild-moderate COVID-19. Systems modelling of cytokine levels paired with deep-immune profiling shows that classical monocytes drive this hyper-inflammatory phenotype and that a reduction in T-lymphocytes correlates with disease severity, with CD8+ cells being disproportionately affected. Antigen presenting machinery expression is also reduced in critical disease. Furthermore, we report that neutrophils contribute to disease severity and local tissue damage by amplification of hypercytokinemia and the formation of neutrophil extracellular traps. Together our findings suggest a myeloid-driven immunopathology, in which hyperactivated neutrophils and an ineffective adaptive immune system act as mediators of COVID-19 disease severity.

Early lung ultrasound assessment for the prognosis of patients hospitalized for COVID-19 pneumonia. A pilot study.

OBJECTIVE: SARS CoV-2 is an epidemic viral infection that can cause mild to severe lung involvement. Newly apprehended knowledge on thoracic imaging abnormalities and the growing clinical experience on the evolution of this disease make the radiographic follow-up of hospitalized patients relevant. The value of consecutive bedside lung ultrasonography in the follow-up of hospitalized patients with SARS CoV-2 pneumonia and its correlation with other clinical and laboratory markers needs to be evaluated. METHODS: We assessed 39 patients [age: 64 y(60.1-68.7)] with confirmed SARS CoV-2 pneumonia. A total of 24 patients were hospitalized until the follow-up test, 9 were discharged early and 6 required a transfer to critical care unit. Two ultrasound scans of the lung were performed on day 1 and 4 of patients' hospitalization. Primary endpoint was the magnitude of association between a global lung ultrasound score (LUS) and clinical and laboratory markers. Secondary endpoint was the association between the evolution of LUS with the corresponded changes in clinical and laboratory outcomes during hospitalization period. RESULTS: LUS score on admission was higher among the deteriorating patients and significantly (P=0.038-0.0001) correlated (Spearman's rho) with the levels of C-reactive protein (0.58), lymphocytes (-0.33), SpO2 (-0.48) and oxygen supplementation (0.48) upon admission. The increase in LUS score between the two scans was significantly correlated (0.544, P=0.006) with longer hospital stay. CONCLUSION: Lung ultrasound assessment can be a useful as an imaging modality for SARS CoV-2 patients. Larger studies are needed to further investigate the predictive role of LUS in the duration and the outcome of the hospitalization of these patients.

National Survey on the Management of Adult Bronchiectasis in Belgium.

The increasing prevalence and incidence of bronchiectasis leads to a substantial health care burden. Quality standards for the management of bronchiectasis were formulated by the British Thoracic Society following publication of guidelines in 2010. They can be used as a benchmark for quality of care. It is, however, unclear how and whether they apply outside of the UK. Between May and November 2017, we conducted an online survey among respiratory physicians caring for adult bronchiectasis patients in Belgium. About 186 cases were submitted by 117 treating physicians. Patients were mostly female (58%), of Caucasian descent (84%) with a remarkably low median age of 59.8 (IQR 47-73) years. 41% had Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus and/or Enterobacteriaceae isolated from respiratory samples in the past. 21% had three or more exacerbations, however, more than 58% were receiving long-term oral antibiotics (of which 90% azithromycin). In 40% of patients the diagnostic testing was insufficient. Surveillance of sputum bacteriology in stable patients and composing a self-management plan was missing in 53% and 68% of patients, respectively. Airway clearance techniques were implemented in 84%. Respiratory physicians complied with 60% or more to five out of the eight applicable quality standards, which is encouraging. Increasing educational act could further raise awareness and increase quality of care.

Continuous alternating inhaled antibiotic therapy in CF: A single center retrospective analysis.

INTRODUCTION: The efficacy of inhaled antibiotics to treat chronic Pseudomonas aeruginosa pulmonary infection in patients with cystic fibrosis (CF) has been well established. Few data are available on the value of continuous alternating inhaled antibiotic therapy (CAIT), a strategy increasingly used in the management of CF. OBJECTIVE: To investigate the effect of CAIT on clinical outcome in adult CF patients treated at the University Hospital Leuven. METHODS: Patients with a documented CF diagnosis who received inhaled antibiotics between March 2010 and January 2015 were retrospectively evaluated. In patients receiving CAIT patient characteristics, recorded spirometry data and number of IV antibiotic days were collected retrospectively at fixed time intervals, from 6months before to one year after the start of the 2nd inhaled antibiotic. For patients on inhaled antibiotic monotherapy (IAMT), the same data were obtained at similar intervals during the study period. RESULTS: A total of 49 of 89 patients using chronic inhaled antibiotic therapy received CAIT. Patients receiving CAIT had a lower baseline FEV1 and were more likely to be homozygous for F508del compared to patients receiving IAMT. FEV1 deteriorated on average by a factor of 0.904 per year (95% CI: 0.851-0.960) prior to the start of CAIT. The initiation of CAIT was associated with an average improvement in FEV1 by a factor of 1.148 per year (95% CI: 1.068-1.236, p=0.0002). The analysis of specific types of antibiotics revealed evidence of positive effects of adding COLI to TOBI and COLI to AZLI. We found no effect of the initiation of CAIT on the number of IV antibiotic days (p=0.80). CONCLUSION: CF patients with more advanced lung disease are more likely to receive CAIT. In this patient group, CAIT was associated with a significant improvement in FEV1. Further data are warranted to identify the value of CAIT.

Systematic screening for drug-resistant tuberculosis with Xpert(®) MTB/RIF in a referral hospital in Cambodia.

SETTING: Limited access to drug susceptibility testing (DST) in referral hospitals contributes to delayed detection of multidrug-resistant tuberculosis (MDR-TB). OBJECTIVE: To document the impact of identifying rifampicin (RMP) resistance using Xpert(®) MTB/RIF on time to diagnosis and time to treatment, and evaluate its performance under programmatic conditions. METHODS: Using a prospective observational study, we screened presumptive MDR-TB cases with Xpert and solid culture/conventional DST. RMP resistance was confirmed using a line-probe assay (LPA). We recorded diagnostic and treatment delays. We performed rpoB gene sequencing post hoc to resolve discordant RMP susceptibilities. RESULTS: We screened 299 of 345 presumptive MDR-TB individuals, and identified 44 Xpert RMP-resistant cases: 16/165 (10%) were new and 28/136 (20%) retreated. The median time to diagnosis was 2 days (Xpert) vs. an additional 6 with LPA; the median time to treatment was 14 days. Confirmatory LPA on 39/44 revealed 27 concordant, 6 discordant and 6 invalid results. Xpert RMP resistance was confirmed in respectively 24/30 (80%) and 21/23 (91%) by phenotypic DST and rpoB sequencing. CONCLUSION: Screening presumptive MDR-TB patients with Xpert enabled rapid diagnosis and treatment of MDR-TB. Xpert performed well, provided appropriate risk assessment was done. Rapid confirmatory testing added little to clinical decision making. Our findings support the latest World Health Organization guidelines to abandon confirmatory LPA in favour of repeat Xpert when in clinical doubt, pending phenotypic DST.

Is frontloaded sputum microscopy an option in active tuberculosis case finding?

SETTING: Active tuberculosis (TB) case finding (ACF) in Phnom Penh, Cambodia using light-emitting diode fluorescence microscopy (FM). OBJECTIVE: To evaluate the smear-positive yield of frontloaded (same-day) smear microscopy in ACF. DESIGN: All presumptive TB cases screened through ACF were asked to provide three sputum specimens: two spot specimens on Day 1 and a morning specimen on Day 2 (spot-spot-morning, SSM). Laboratory technicians blinded to previous results read the smears using FM. We considered only SSM series with at least one positive smear to calculate the proportion of TB cases missed and to determine the difference between the spot-spot (SS) and spot-morning (SM) approach. RESULTS: Of 4616 presumptive TB patients enrolled, 3306 provided three sputum samples. Of 2957 (89.4%) who followed the SSM approach, 188 (6.4%) were smear-positive: 177 on SM and 160 on SS. The incremental yield of the second sputum sample was 18.1% for SM vs. 9.4% for SS. Relative to any smear-positive case detected by SSM, 28/188 (14.9%, 95%CI 10.1-20.8) TB cases would be missed by SS vs. 11/188 (5.9%, 95%CI 3.0-10.2) by SM. The difference in the proportion of missed TB patients was 9.0% (P = 0.006). CONCLUSION: ACF frontloaded sputum microscopy is inferior in terms of smear-positive yield: the SS approach would have missed a significant proportion of smear-positive TB.

Risk factors for delay in the diagnosis and treatment of tuberculosis at a referral hospital in Rwanda.

SETTING: Kigali University Hospital, the main referral centre for TB in Rwanda. OBJECTIVE: To evaluate delays in the diagnosis and treatment of tuberculosis (TB) and associated risk factors. DESIGN: Prospective data collection of patients treated for pulmonary TB (PTB) or extra-pulmonary TB (EPTB) between June and September 2006. RESULTS: Of 104 patients with a mean age of 35 years (range 17-84) recruited into the study, 62% were HIV-positive. EPTB was diagnosed in 60 cases. The median total, health care and patient delays were respectively 57, 28 and 25 days. The health system delay before referral was significantly longer than the delay at our institution (18 vs. 6 days, P<0.0001). Risk factors for a longer health system delay at our institution were smear-negative PTB or EPTB (OR 5.12) and a trial of antibiotics (OR 2.96). The latter was also found to significantly prolong total delay (OR 2.85), as did rural residence (OR 4.86). No significant association was found between patient delay and age, sex, profession or health insurance status. CONCLUSION: Smear-negative PTB and EPTB were associated with longer health system delays. A trial of antibiotics significantly increased the health system delay. Its use, recommended by the World Health Organization in case of smear-negative TB and EPTB in developing countries, needs validation at the tertiary health care level.

Long-term survival of surgically staged IIIA-N2 non-small-cell lung cancer treated with surgical combined modality approach: analysis of a 7-year prospective experience.

BACKGROUND: The aim of this study was to analyse the outcome of surgically staged IIIA-N2 non-small-cell lung cancer (NSCLC) treated with induction chemotherapy followed by surgical exploration. METHODS: Univariate and multivariate analyses were carried out on a prospective cohort of 131 mediastinoscopy-proven IIIA-N2 NSCLC patients. Three preoperative cycles of vindesine-ifosfamide-cisplatin (VIP) were given. Patients with at least stable disease (SD) were considered for surgery, or radical radiotherapy in selected cases. RESULTS: The response rate after VIP was 54% (95% confidence interval 45% to 63%) and was important for the final outcome. The median and 5-year survival for the total group were 24 months and 21% (38 months and 30% in responders), respectively. Involvement of subcarinal nodes at diagnosis was the most important prognostic factor (P=0.022). Seventy-five patients were considered for surgery. Downstaging occurred in 34 of 70 resection specimens, with a pathological complete response in six. Median and 5-year survival in the surgical cohort were 45 months and 35%, respectively. Surgery was rewarding both in patients with a response and in those with SD, although the complete resection rate was significantly lower in the latter. On multivariate analysis, favourable prognostic factors were low pathological T-stage (P=0.001) and downstaging of mediastinal nodes in the resection specimen (P=0.008). CONCLUSIONS: VIP induction chemotherapy followed by surgical exploration was rewarding in mediastinoscopy-proven stage IIIA-N2 NSCLC, both in cases of response and SD, despite a lower complete resection rate in the latter. Patients with subcarinal nodes at diagnosis (5-year survival 8.5%) or without nodal downstaging at post-induction surgery (13.7%) might preferably be treated with a non-surgical approach.