Patient Selection for Bronchoscopic Lung Volume Reduction

Purpose: Bronchoscopic lung volume reduction (BLVR) is a valuable treatment option for carefully selected patients with severe COPD. There is limited knowledge about the characteristics and outcomes of patients referred to a specialized center for BLVR. The study objectives were to investigate the selection rate for BLVR treatment in patients referred for this treatment and to investigate the differences between patients that were selected for BLVR and patients that were not. Patients and Methods: We performed a retrospective analysis of patients with severe COPD who were referred to our hospital to assess eligibility for BLVR treatment. Our parameters included demographics, comorbidity, chest computed tomography characteristics, reasons for rejection from BLVR treatment and patient survival. Results: In total, 1500 patients were included (mean age 62 years, 50% female and forced expiratory volume in 1 s 33% of predicted). Out of this group, 282 (19%) patients were selected for BLVR treatment. The absence of a suitable target lobe for treatment, an unsuitable disease phenotype and insufficient lung hyperinflation were the most important factors for not being selected. Patients that were selected for any BLVR option lived significantly longer than the group of patients that were not selected for BLVR (median 3060 versus 2079 days, P<0.001). Conclusion: We found that only a small proportion of patients that are referred for BLVR treatment is eligible for a BLVR treatment, indicating a need for both better referral tools and for the development of new therapies for this group of patients. Furthermore, our data suggest that selection for BLVR is associated with a significant survival benefit

Comparison of Multiple Diagnostic Tests to Measure Dynamic Hyperinflation in Patients with Severe Emphysema Treated with Endobronchial Coils

PURPOSE: For this study, we aimed to compare dynamic hyperinflation measured by cardiopulmonary exercise testing (CPET), a six-minute walking test (6-MWT), and a manually paced tachypnea test (MPT) in patients with severe emphysema who were treated with endobronchial coils. Additionally, we investigated whether dynamic hyperinflation changed after treatment with endobronchial coils. METHODS: Dynamic hyperinflation was measured with CPET, 6-MWT, and an MPT in 29 patients before and after coil treatment. RESULTS: There was no significant change in dynamic hyperinflation after treatment with coils. Comparison of CPET and MPT showed a strong association (rho 0.660, p < 0.001) and a moderate agreement (BA-plot, 202 ml difference in favor of MPT). There was only a moderate association of the 6-MWT with CPET (rho 0.361, p 0.024). CONCLUSION: MPT can be a suitable alternative to CPET to measure dynamic hyperinflation in severe emphysema but may overestimate dynamic hyperinflation possibly due to a higher breathing frequency

Significant Differences in Body Plethysmography Measurements Between Hospitals in Patients Referred for Bronchoscopic Lung Volume Reduction

During the evaluation of potential bronchoscopic lung volume reduction (BLVR) candidates in our hospital, we frequently observe patients with a lower residual volume (RV) value compared to the value measured in their referring hospital, although both measured by body plethysmography. We explored to what degree RV and other pulmonary function measurements match between referring hospitals and our hospital. We retrospectively analyzed a total of 300 patients with severe emphysema [38% male, median age 62 years (range 38-81), median forced expiratory volume in 1 s 29% (range 14-65) of predicted, and a median of 40 packyears (range 2-125)]. We measured a median RV of 4.47 l (range 1.70-7.57), which was a median 310 ml lower than in the referring hospitals (range - 3.04 to + 1.94), P < 0.001). In conclusion, this retrospective analysis demonstrated differences in RV measurements between different hospitals in patients with severe emphysema. Overestimation of RV can lead to unnecessary referrals for BLVR and potential treatment failures. To avoid disappointment and unnecessary hospital visits, it is important that body plethysmography measurements are accurately performed by applying preferably the unlinked method in these patients

Identifying Responders and Exploring Mechanisms of Action of the Endobronchial Coil Treatment for Emphysema

Background: So far, 3 randomized controlled trials have shown that the endobronchial treatment using coils is safe and effective. However, the more exact underlying mechanism of the treatment and best predictors of response are unknown. Objectives: The aim of the study was to gain more knowledge about the underlying physiological mechanism of the lung volume reduction coil treatment and to identify potential predictors of response to this treatment. Methods: This was a prospective nonrandomized single-center study which included patients who were bilaterally treated with coils. Patients underwent an extensive number of physical tests at baseline and 3 months after treatment. Results: Twenty-four patients (29% male, mean age 62 years, forced expiratory volume in 1 s [FEV1] 26% pred, residual volume (RV) 231% pred) were included. Three months after treatment, significant improvements were found in spirometry, static hyperinflation, air trapping, airway resistance, treated lobe RV and treated lobes air trapping measured on CT scan, exercise capacity, and quality of life. The change in RV and airway resistance was significantly associated with a change in FEV1, forced vital capacity, air trapping, maximal expiratory pressure, dynamic compliance, and dynamic hyperinflation. Predictors of treatment response at baseline were a higher RV, larger air trapping, higher emphysema score in the treated lobes, and a lower physical activity level. Conclusions: Our results confirm that emphysema patients benefit from endobronchial coil treatment. The primary mechanism of action is decreasing static hyperinflation with improvement of airway resistance which consequently changes dynamic lung mechanics. However, the right patient population needs to be selected for the treatment to be beneficial which should include patients with severe lung hyperinflation, severe air trapping, and significant emphysema in target lobes

TB Hackathon: Development and Comparison of Five Models to Predict Subnational Tuberculosis Prevalence in Pakistan

Pakistan’s national tuberculosis control programme (NTP) is among the many programmes worldwide that value the importance of subnational tuberculosis (TB) burden estimates to support disease control efforts, but do not have reliable estimates. A hackathon was thus organised to solicit the development and comparison of several models for small area estimation of TB. The TB hackathon was launched in April 2019. Participating teams were requested to produce district-level estimates of bacteriologically positive TB prevalence among adults (over 15 years of age) for 2018. The NTP provided case-based data from their 2010–2011 TB prevalence survey, along with data relating to TB screening, testing and treatment for the period between 2010–2011 and 2018. Five teams submitted district-level TB prevalence estimates, methodological details and programming code. Although the geographical distribution of TB prevalence varied considerably across models, we identified several districts with consistently low notification-to-prevalence ratios. The hackathon highlighted the challenges of generating granular spatiotemporal TB prevalence forecasts based on a cross-sectional prevalence survey data and other data sources. Nevertheless, it provided a range of approaches to subnational disease modelling. The NTP’s use and plans for these outputs shows that, limitations notwithstanding, they can be valuable for programme planning

Characterization of gut microbial structural variations as determinants of human bile acid metabolism

Bile acids (BAs) facilitate intestinal fat absorption and act as important signaling molecules in host-gut microbiota crosstalk. BA-metabolizing pathways in the microbial community have been identified, but it remains largely unknown how the highly variable genomes of gut bacteria interact with host BA metabolism. We characterized 8,282 structural variants (SVs) of 55 bacterial species in the gut microbiomes of 1,437 individuals from two cohorts and performed a systematic association study with 39 plasma BA parameters. Both variations in SV-based continuous genetic makeup and discrete clusters showed correlations with BA metabolism. Metagenome-wide association analysis identified 809 replicable associations between bacterial SVs and BAs and SV regulators that mediate the effects of lifestyle factors on BA metabolism. This is the largest microbial genetic association analysis to demonstrate the impact of bacterial SVs on human BA composition, and it highlights the potential of targeting gut microbiota to regulate BA metabolism through lifestyle intervention

TB hackathon : development and comparison of five models to predict subnational tuberculosis prevalence in Pakistan

Pakistan's national tuberculosis control programme (NTP) is among the many programmes worldwide that value the importance of subnational tuberculosis (TB) burden estimates to support disease control efforts, but do not have reliable estimates. A hackathon was thus organised to solicit the development and comparison of several models for small area estimation of TB. The TB hackathon was launched in April 2019. Participating teams were requested to produce district-level estimates of bacteriologically positive TB prevalence among adults (over 15 years of age) for 2018. The NTP provided case-based data from their 2010-2011 TB prevalence survey, along with data relating to TB screening, testing and treatment for the period between 2010-2011 and 2018. Five teams submitted district-level TB prevalence estimates, methodological details and programming code. Although the geographical distribution of TB prevalence varied considerably across models, we identified several districts with consistently low notification-to-prevalence ratios. The hackathon highlighted the challenges of generating granular spatiotemporal TB prevalence forecasts based on a cross-sectional prevalence survey data and other data sources. Nevertheless, it provided a range of approaches to subnational disease modelling. The NTP's use and plans for these outputs shows that, limitations notwithstanding, they can be valuable for programme planning

Intracellular pyruvate levels positively correlate with cytokine production capacity in tolerant monocytes from patients with pneumonia

Background: Community-acquired pneumonia (CAP) is responsible for a high morbidity and mortality worldwide. Monocytes are essential for pathogen recognition and the initiation of an innate immune response. Immune cells induce intracellular glycolysis upon activation to support several functions. Objective: To obtain insight in the metabolic profile of blood monocytes during CAP, with a focus on glycolysis and branching metabolic pathways, and to determine a possible association between intracellular metabolite levels and monocyte function. Methods: Monocytes were isolated from blood of patients with CAP within 24 h of hospital admission and from control subjects matched for age, sex and chronic comorbidities. Changes in glycolysis, oxidative phosphorylation (OXPHOS), tricarboxylic acid (TCA) cycle and the pentose phosphate pathway were investigated through RNA sequencing and metabolomics measurements. Monocytes were stimulated ex vivo with lipopolysaccharide (LPS) to determine their capacity to produce tumor necrosis factor (TNF), interleukin (IL)-1β and IL-10. Results: 50 patients with CAP and 25 non-infectious control subjects were studied. When compared with control monocytes, monocytes from patients showed upregulation of many genes involved in glycolysis, including PKM, the gene encoding pyruvate kinase, the rate limiting enzyme for pyruvate production. Gene set enrichment analysis of OXPHOS, the TCA cycle and the pentose phosphate pathway did not reveal differences between monocytes from patients and controls. Patients' monocytes had elevated intracellular levels of pyruvate and the TCA cycle intermediate α-ketoglutarate. Monocytes from patients were less capable of producing cytokines upon LPS stimulation. Intracellular pyruvate (but not α-ketoglutarate) concentrations positively correlated with IL-1β and IL-10 levels released by patients' (but not control) monocytes upon exposure to LPS. Conclusion: These results suggest that elevated intracellular pyruvate levels may partially maintain cytokine production capacity of hyporesponsive monocytes from patients with CAP.peer-reviewe

Spectrum of Phenotypic, Genetic, and Functional Characteristics in Patients With Epilepsy With KCNC2 Pathogenic Variants

Background and ObjectivesKCNC2 encodes Kv3.2, a member of the Shaw-related (Kv3) voltage-gated potassium channel subfamily, which is important for sustained high-frequency firing and optimized energy efficiency of action potentials in the brain. The objective of this study was to analyze the clinical phenotype, genetic background, and biophysical function of disease-associated Kv3.2 variants.MethodsIndividuals with KCNC2 variants detected by exome sequencing were selected for clinical, further genetic, and functional analysis. Cases were referred through clinical and research collaborations. Selected de novo variants were examined electrophysiologically in Xenopus laevis oocytes.ResultsWe identified novel KCNC2 variants in 18 patients with various forms of epilepsy, including genetic generalized epilepsy (GGE), developmental and epileptic encephalopathy (DEE) including early-onset absence epilepsy, focal epilepsy, and myoclonic-atonic epilepsy. Of the 18 variants, 10 were de novo and 8 were classified as modifying variants. Eight drug-responsive patients became seizure-free using valproic acid as monotherapy or in combination, including severe DEE cases. Functional analysis of 4 variants demonstrated gain of function in 3 severely affected DEE cases and loss of function in 1 case with a milder phenotype (GGE) as the underlying pathomechanisms.DiscussionThese findings implicate KCNC2 as a novel causative gene for epilepsy and emphasize the critical role of KV3.2 in the regulation of brain excitability