Anti-inflammatory effects of elexacaftor/tezacaftor/ivacaftor in adults with cystic fibrosis heterozygous for F508del.

Inflammation is a key driver in the pathogenesis of cystic fibrosis (CF). We assessed the effectiveness of elexacaftor/tezacaftor/ivacaftor (ETI) therapy on downregulating systemic and immune cell-derived inflammatory cytokines. We also monitored the impact of ETI therapy on clinical outcome. Adults with CF, heterozygous for F508del (n = 19), were assessed at baseline, one month and three months following ETI therapy, and clinical outcomes were measured, including sweat chloride, lung function, weight, neutrophil count and C-reactive protein (CRP). Cytokine quantifications were measured in serum and following stimulation of peripheral blood mononuclear cells (PBMCs) with lipopolysaccharide (LPS) and adenosine triphosphate and analysed using LEGEND plex™ Human Inflammation Panel 1 by flow cytometry (n = 19). ASC specks were measured in serum and caspase-1 activity and mRNA levels determined from stimulated PBMCs were determined. Patients remained stable over the study period. ETI therapy resulted in decreased sweat chloride concentrations (p < 0.0001), CRP (p = 0.0112) and neutrophil count (p = 0.0216) and increased percent predicted forced expiratory volume (ppFEV1) (p = 0.0399) from baseline to three months, alongside a trend increase in weight. Three months of ETI significantly decreased IL-18 (p< 0.0011, p < 0.0001), IL-1ß (p<0.0013, p = 0.0476), IL-6 (p = 0.0109, p = 0.0216) and TNF (p = 0.0028, p = 0.0033) levels in CF serum and following PBMCs stimulation respectively. The corresponding mRNA levels were also found to be reduced in stimulated PBMCs, as well as reduced ASC specks and caspase-1 levels, indicative of NLRP3-mediated production of pro-inflammatory cytokines, IL-1ß and IL-18. While ETI therapy is highly effective at reducing sweat chloride and improving lung function, it also displays potent anti-inflammatory properties, which are likely to contribute to improved long-term clinical outcomes.

Anti-IL-5 biologics and rheumatoid arthritis: a single-centre 500 patient year exposure analysis.

OBJECTIVE: The increasing use of biological therapies has led to the paradoxical finding that monoclonal antibody therapy for one inflammatory disease can sometimes induce another inflammatory disease. Recently, the use of anti-IL-5 (IL, interleukin) antibody therapies for severe asthma has been associated with the onset of rheumatoid arthritis (RA) and other inflammatory rheumatological disease. We undertook this audit to identify the prevalence of this finding across a large clinical cohort of patients receiving anti-IL-5 therapy. METHODS: All patients currently receiving mepolizumab or benralizumab for severe asthma across the Leeds Teaching Hospitals NHS Trust's (LTHT) Respiratory Service were included. Electronic records for each patient were searched to identify clinical and biochemical manifestations of inflammatory rheumatological disease following the initiation of anti-IL-5 therapy. RESULTS: 142 patients, with a mean duration of 3.5 years on therapy, were included (89 mepolizumab, 53 benralizumab). 17 patients developed new arthralgias (nine mepolizumab, eight benralizumab), however only one of these patients (on mepolizumab) had raised acute phase reactants and newly positive anti-CCP antibody (ACPA) and rheumatoid factor and was the only patient to receive a formal diagnosis of RA. CONCLUSION: Although ACPA positive RA has now been reported in a handful of case reports, we noted a very low rate of evolution into RA or inflammatory arthritis, at least in the short-medium term under anti-IL-5 therapy. This challenges the emerging suggestion that anti-IL-5 biologics may be triggering RA.

Physical activity promotion interventions in chronic airways disease: a systematic review and meta-analysis.

Physical inactivity is common in people with chronic airways disease (pwCAD) and associated with worse clinical outcomes and impaired quality of life. We conducted a systematic review and meta-analysis to characterise and evaluate the effectiveness of interventions promoting step-based physical activity (PA) in pwCAD. We searched for studies that included a form of PA promotion and step-count outcome measure. A random-effects model was used to determine the overall effect size using post-intervention values. 38 studies (n=32 COPD; n=5 asthma; n=1 bronchiectasis; study population: n=3777) were included. Overall, implementing a form of PA promotion resulted in a significant increase in step-count: median (IQR) 705 (183-1210) when compared with usual standard care: -64 (-597-229), standardised mean difference (SMD) 0.24 (95% CI: 0.12-0.36), p<0.01. To explore the impact of specific interventions, studies were stratified into subgroups: PA promotion+wearable activity monitor-based interventions (n=17) (SMD 0.37, p<0.01); PA promotion+step-count as an outcome measure (n=9) (SMD 0.18, p=0.09); technology-based interventions (n=12) (SMD 0.16, p=0.01). Interventions promoting PA, particularly those that incorporate wearable activity monitors, result in a significant and clinically meaningful improvement in daily step-count in pwCAD.

Biochemical and Structural Insights into FIH-Catalysed Hydroxylation of Transient Receptor Potential Ankyrin Repeat Domains.

Transient receptor potential (TRP) channels have important roles in environmental sensing in animals. Human TRP subfamily A member 1 (TRPA1) is responsible for sensing allyl isothiocyanate (AITC) and other electrophilic sensory irritants. TRP subfamily vanilloid member 3 (TRPV3) is involved in skin maintenance. TRPV3 is a reported substrate of the 2-oxoglutarate oxygenase factor inhibiting hypoxia-inducible factor (FIH). We report biochemical and structural studies concerning asparaginyl hydroxylation of the ankyrin repeat domains (ARDs) of TRPA1 and TRPV3 catalysed by FIH. The results with ARD peptides support a previous report on FIH-catalysed TRPV3 hydroxylation and show that, of the 12 potential TRPA1 sequences investigated, one sequence (TRPA1 residues 322-348) undergoes hydroxylation at Asn336. Structural studies reveal that the TRPA1 and TRPV3 ARDs bind to FIH with a similar overall geometry to most other reported FIH substrates. However, the binding mode of TRPV3 to FIH is distinct from that of other substrates.

Resistance to the isocitrate dehydrogenase 1 mutant inhibitor ivosidenib can be overcome by alternative dimer-interface binding inhibitors.

Ivosidenib, an inhibitor of isocitrate dehydrogenase 1 (IDH1) R132C and R132H variants, is approved for the treatment of acute myeloid leukaemia (AML). Resistance to ivosidenib due to a second site mutation of IDH1 R132C, leading to IDH1 R132C/S280F, has emerged. We describe biochemical, crystallographic, and cellular studies on the IDH1 R132C/S280F and R132H/S280F variants that inform on the mechanism of second-site resistance, which involves both modulation of inhibitor binding at the IDH1 dimer-interface and alteration of kinetic properties, which enable more efficient 2-HG production relative to IDH1 R132C and IDH1 R132H. Importantly, the biochemical and cellular results demonstrate that it should be possible to overcome S280F mediated resistance in AML patients by using alternative inhibitors, including some presently in phase 2 clinical trials.

Ward based inhaler technique service reduces exacerbations of asthma and COPD.

BACKGROUND: The management of asthma and COPD is largely dependent on patients being able to use their inhaled medication correctly, but poor inhaler technique continues to be a recurring theme in studies and clinical practice. This is associated with poor disease control, increased risk of exacerbations and hospital admissions, and so there is a need to redesign services for patients to optimise their medicines use. METHODS: A novel ward-based dedicated inhaler technique service was developed, and pharmacy support workers trained to provide this, focusing on optimising inhaler technique using a checklist and recommending protocol-guided inhaler device switches. Inpatients on adult respiratory wards with a diagnosis of exacerbation of asthma or COPD consented to receive this service, and the impact on exacerbations and hospital admissions were compared in the 6-months before and after the intervention. RESULTS: 266 adults (74 asthma, 188 COPD, and four asthma-COPD overlap) received the inhaler technique service. Six-month exacerbation and hospital admission data were available for 184 subjects. Optimising inhaler technique achieved a significant reduction in the combined asthma and COPD annualised rate of moderate-to-severe exacerbations (Rate Ratio [RR] 0.75, p < 0.05) and annualised rate of hospital admissions (RR 0.57, p < 0.0005). Improvements were also observed in future length of stay (- 1.6 days) and the average cost of admission (-£748). CONCLUSIONS: This novel inhaler technique service produced a significant reduction in the rate of moderate-to-severe exacerbations of asthma and COPD, and a reduction in the rate hospital admissions, length of stay and average cost of admission.

Nasal high-flow therapy as an adjunct to exercise in patients with cystic fibrosis: A pilot feasibility trial.

BACKGROUND: Exercise tolerance in people with CF and advanced lung disease is often reduced. While supplemental oxygen can improve oxygenation, it does not affect dyspnoea, fatigue or comfort. Nasal high-flow therapy (NHFT), thanks to its pathophysiological mechanisms, could improve exercise tolerance, saturation and dyspnoea. This study explores the feasibility of conducting a clinical trial of using NHFT in patients with CF during exercise. METHODS: A pilot, open-label, randomized crossover trial was performed, enroling 23 participants with CF and severe lung disease. Participants completed two treadmill walking test (TWT) with and without NHFT at 24-48 h interval. Primary outcome was trial feasibility, and exploratory outcomes were TWT distance (TWTD), SpO2, transcutaneous CO2, dyspnoea and comfort. RESULTS: Recruitment rate was 2.4 subjects/month with 1.3:1 screening-to-randomization ratio. No adverse events caused by NHFT were observed. Tolerability was good and data completion rate was 100%. Twenty subjects (91%) were included in the exploratory study. Mean difference in TWTD on NHFT was 19 m (95% CI [4.8 - 33.1]). SpO2 was similar, but respiratory rate and mean tcCO2 were lower on NHFT (mean difference = -3.9 breaths/min 95% CI [-5.9 - -1.9] and -0.22 kPa 95% CI [-0.4 - 0.04]). NHFT reduced exercise-induced dyspnoea and discomfort. CONCLUSION: Trials using NHFT in patients with CF during exercise are feasible. NHFT appears to improve walking distance, control respiratory rate, CO2, dyspnoea and improve comfort. A larger trial with a longer intervention is feasible and warranted to confirm the impact of NHFT in training programmes for patients with CF.

Effects of patient room layout on viral accruement on healthcare professionals' hands.

Healthcare professionals (HCPs) are exposed to highly infectious viruses, such as norovirus, through multiple exposure routes. Understanding exposure mechanisms will inform exposure mitigation interventions. The study objective was to evaluate the influences of hospital patient room layout on differences in HCPs' predicted hand contamination from deposited norovirus particles. Computational fluid dynamic (CFD) simulations of a hospital patient room were investigated to find differences in spatial deposition patterns of bioaerosols for right-facing and left-facing bed layouts under different ventilation conditions. A microbial transfer model underpinned by observed mock care for three care types (intravenous therapy (IV) care, observational care, and doctors' rounds) was applied to estimate HCP hand contamination. Viral accruement was contrasted between room orientation, care type, and by assumptions about whether bioaerosol deposition was the same or variable by room orientation. Differences in sequences of surface contacts were observed for care type and room orientation. Simulated viral accruement differences between room types were influenced by mostly by differences in bioaerosol deposition and by behavior sequences when deposition patterns for the room orientations were similar. Differences between care types were likely driven by differences in hand-to-patient contact frequency, with doctors' rounds resulting in the greatest predicted viral accruement on hands.

Noninvasive Ventilation in Cystic Fibrosis: Clinical Indications and Outcomes in a Large UK Adult Cystic Fibrosis Center.

BACKGROUND: Noninvasive ventilation (NIV) is routinely used to treat patients with cystic fibrosis and respiratory failure. However, evidence on its use is limited, with no data on its role in disease progression and outcomes. The aim of this study was to assess the indications of NIV use and to describe the outcomes associated with NIV in adults with cystic fibrosis in a large adult tertiary center. METHODS: A retrospective analysis of data captured prospectively on the unit electronic patient records was performed. All patients with cystic fibrosis who received NIV over a 10-y period were included in the study. A priori, 2 groups were identified based on length of follow-up, with 2 subgroups identified based on duration of NIV treatment. RESULTS: NIV was initiated on 64 occasions. The duration of follow-up was categorized as > 6 months or < 6 months in 31 (48.4%) and 33 (51.6%) occasions, respectively. The most common indications for starting NIV were chronic (48.5%) and acute (32.8%) hypercapnic respiratory failure. Among those with a follow-up > 6 months, subjects who stopped using NIV early showed a steady median (interquartile range) decline in FEV1 (pre-NIV: -0.04 [-0.35 to 0.03] L/y vs post-NIV: -0.07 [-0.35 to 0.01] L/y, P = .51), while among those who continued using it had an improvement in the rate of decline (pre-NIV: -0.25 [-0.52 to -0.02] L/y vs post-NIV: -0.07 [-0.13 to 0.16] L/y, P = .006). No differences in intravenous antibiotic requirement or pulmonary exacerbations were noted with the use of NIV. Pneumothorax and massive hemoptysis occurred independently in 4 cases. CONCLUSIONS: NIV is being used in cystic fibrosis as adjunct therapy for the management of advanced lung disease in a similar fashion to other chronic respiratory conditions. Adherence to NIV treatment can stabilize lung function but does not reduce pulmonary exacerbations or intravenous antibiotic requirement.

Development of an integrated rehabilitation pathway for individuals recovering from COVID-19 in the community.

OBJECTIVE: COVID-19 is a multisystem illness that has considerable long-term physical, psychological, cognitive, social and vocational sequelae in survivors. Given the scale of this burden and lockdown measures in most countries, there is a need for an integrated rehabilitation pathway using a tele-medicine approach to screen and manage these sequelae in a systematic and efficient way. METHODS: A multidisciplinary team of professionals in the UK developed a comprehensive pragmatic telephone screening tool, the COVID-19 Yorkshire Rehabilitation Screen (C19-YRS), and an integrated rehabilitation pathway, which spans the acute hospital trust, community trust and primary care service within the National Health Service (NHS) service model. RESULTS: The C19-YRS telephone screening tool, developed previously, was used to screen symptoms and grade their severity. Referral criteria thresholds were applied to the output of C19-YRS to inform the decision-making process in the rehabilitation pathway. A dedicated multidisciplinary COVID-19 rehabilitation team is the core troubleshooting forum for managing complex cases with needs spanning multiple domains of the health condition. CONCLUSION: The authors recommend that health services dealing with the COVID-19 pandemic adopt a comprehensive telephone screening system and an integrated rehabilitation pathway to manage the large number of survivors in a timely and effective manner and to enable the provision of targeted interventions.

Breathlessness in palliative care: a practical guide.

Breathlessness is a common symptom for patients with terminal illness and can be challenging to manage. Breathlessness is acknowledged to be an interaction between body and mind. There are a variety of pharmacological and non-pharmacological therapies that can be beneficial. The holistic assessment of the breathlessness patient should enable delivery of a tailored package of care focused on relief of symptoms.

Level of accuracy of diagnoses recorded in discharge summaries: A cohort study in three respiratory wards.

RATIONALE: One of the key functions of the discharge summary is to convey accurate diagnostic description of patients. Inaccurate or missing diagnoses may result in a false clinical picture, inappropriate management, poor quality of care, and a higher risk of re-admission. While several studies have investigated the presence or absence of diagnoses within discharge summaries, there are very few published studies assessing the accuracy of these diagnoses. The aim of this study was to measure the accuracy of diagnoses recorded in sample summaries, and to determine if it was correlated with the type of diagnoses (eg, "respiratory" diagnoses), the number of diagnoses, or the length of patient stay. METHODS: A prospective cohort study was conducted in three respiratory wards in a large UK NHS Teaching Hospital. We determined the reference list of diagnoses (the closest to the true state of the patient based on consultant knowledge, patient records, and laboratory investigations) for comparison with the diagnoses recorded in a discharge summary. To enable objective comparison, all patient diagnoses were encoded using a standardized terminology (ICD-10). Inaccuracy of the primary diagnosis alone and all diagnoses in discharge summaries was measured and then correlated with type of diseases, number of diagnoses, and length of patient stay. RESULTS: A total of 107 of 110 consecutive discharge summaries were analysed. The mean inaccuracy rate per discharge summary was 55% [95% CI 52 to 58%]. Primary diagnoses were wrong, inaccurate, missing, or mis-recorded as a secondary diagnosis in half the summaries. The inaccuracy rate was correlated with the type of disease but not with number of diagnoses nor length of patient stay. CONCLUSION: Our study showed that diagnoses were not accurately recorded in discharge summaries, highlighting the need to measure and improve discharge summary quality.

The impact of three discharge coding methods on the accuracy of diagnostic coding and hospital reimbursement for inpatient medical care.

BACKGROUND: Coding of diagnoses is important for patient care, hospital management and research. However coding accuracy is often poor and may reflect methods of coding. This study investigates the impact of three alternative coding methods on the inaccuracy of diagnosis codes and hospital reimbursement. METHODS: Comparisons of coding inaccuracy were made between a list of coded diagnoses obtained by a coder using (i)the discharge summary alone, (ii)case notes and discharge summary, and (iii)discharge summary with the addition of medical input. For each method, inaccuracy was determined for the primary, secondary diagnoses, Healthcare Resource Group (HRG) and estimated hospital reimbursement. These data were then compared with a gold standard derived by a consultant and coder. RESULTS: 107 consecutive patient discharges were analysed. Inaccuracy of diagnosis codes was highest when a coder used the discharge summary alone, and decreased significantly when the coder used the case notes (70% vs 58% respectively, p < 0.0001) or coded from the discharge summary with medical support (70% vs 60% respectively, p < 0.0001). When compared with the gold standard, the percentage of incorrect HRGs was 42% for discharge summary alone, 31% for coding with case notes, and 35% for coding with medical support. The three coding methods resulted in an annual estimated loss of hospital remuneration of between £1.8 M and £16.5 M. CONCLUSION: The accuracy of diagnosis codes and percentage of correct HRGs improved when coders used either case notes or medical support in addition to the discharge summary. Further emphasis needs to be placed on improving the standard of information recorded in discharge summaries.

Terminally Truncated Isopenicillin N Synthase Generates a Dithioester Product: Evidence for a Thioaldehyde Intermediate during Catalysis and a New Mode of Reaction for Non-Heme Iron Oxidases.

Isopenicillin N synthase (IPNS) catalyses the four-electron oxidation of a tripeptide, l-δ-(α-aminoadipoyl)-l-cysteinyl-d-valine (ACV), to give isopenicillin N (IPN), the first-formed ß-lactam in penicillin and cephalosporin biosynthesis. IPNS catalysis is dependent upon an iron(II) cofactor and oxygen as a co-substrate. In the absence of substrate, the carbonyl oxygen of the side-chain amide of the penultimate residue, Gln330, co-ordinates to the active-site metal iron. Substrate binding ablates the interaction between Gln330 and the metal, triggering rearrangement of seven C-terminal residues, which move to take up a conformation that extends the final α-helix and encloses ACV in the active site. Mutagenesis studies are reported, which probe the role of the C-terminal and other aspects of the substrate binding pocket in IPNS. The hydrophobic nature of amino acid side-chains around the ACV binding pocket is important in catalysis. Deletion of seven C-terminal residues exposes the active site and leads to formation of a new type of thiol oxidation product. The isolated product is shown by LC-MS and NMR analyses to be the ene-thiol tautomer of a dithioester, made up from two molecules of ACV linked between the thiol sulfur of one tripeptide and the oxidised cysteinyl ß-carbon of the other. A mechanism for its formation is proposed, supported by an X-ray crystal structure, which shows the substrate ACV bound at the active site, its cysteinyl ß-carbon exposed to attack by a second molecule of substrate, adjacent. Formation of this product constitutes a new mode of reaction for IPNS and non-heme iron oxidases in general.

13C-Carbamylation as a mechanistic probe for the inhibition of class D ß-lactamases by avibactam and halide ions.

The class D (OXA) serine ß-lactamases are a major cause of resistance to ß-lactam antibiotics. The class D enzymes are unique amongst ß-lactamases because they have a carbamylated lysine that acts as a general acid/base in catalysis. Previous crystallographic studies led to the proposal that ß-lactamase inhibitor avibactam targets OXA enzymes in part by promoting decarbamylation. Similarly, halide ions are proposed to inhibit OXA enzymes via decarbamylation. NMR analyses, in which the carbamylated lysines of OXA-10, -23 and -48 were 13C-labelled, indicate that reaction with avibactam does not ablate lysine carbamylation in solution. While halide ions did not decarbamylate the 13C-labelled OXA enzymes in the absence of substrate or inhibitor, avibactam-treated OXA enzymes were susceptible to decarbamylation mediated by halide ions, suggesting halide ions may inhibit OXA enzymes by promoting decarbamylation of acyl-enzyme complex. Crystal structures of the OXA-10 avibactam complex were obtained with bromide, iodide, and sodium ions bound between Trp-154 and Lys-70. Structures were also obtained wherein bromide and iodide ions occupy the position expected for the 'hydrolytic water' molecule. In contrast with some solution studies, Lys-70 was decarbamylated in these structures. These results reveal clear differences between crystallographic and solution studies on the interaction of class D ß-lactamases with avibactam and halides, and demonstrate the utility of 13C-NMR for studying lysine carbamylation in solution.

Crystallographic analyses of isoquinoline complexes reveal a new mode of metallo-ß-lactamase inhibition.

Crystallographic analyses of the VIM-5 metallo-ß-lactamase (MBL) with isoquinoline inhibitors reveal non zinc ion binding modes. Comparison with other MBL-inhibitor structures directed addition of a zinc-binding thiol enabling identification of potent B1 MBL inhibitors. The inhibitors potentiate meropenem activity against clinical isolates harboring MBLs.

Molecular and cellular mechanisms of HIF prolyl hydroxylase inhibitors in clinical trials.

Inhibition of the human 2-oxoglutarate (2OG) dependent hypoxia inducible factor (HIF) prolyl hydroxylases (human PHD1-3) causes upregulation of HIF, thus promoting erythropoiesis and is therefore of therapeutic interest. We describe cellular, biophysical, and biochemical studies comparing four PHD inhibitors currently in clinical trials for anaemia treatment, that describe their mechanisms of action, potency against isolated enzymes and in cells, and selectivities versus representatives of other human 2OG oxygenase subfamilies. The 'clinical' PHD inhibitors are potent inhibitors of PHD catalyzed hydroxylation of the HIF-α oxygen dependent degradation domains (ODDs), and selective against most, but not all, representatives of other human 2OG dependent dioxygenase subfamilies. Crystallographic and NMR studies provide insights into the different active site binding modes of the inhibitors. Cell-based results reveal the inhibitors have similar effects on the upregulation of HIF target genes, but differ in the kinetics of their effects and in extent of inhibition of hydroxylation of the N- and C-terminal ODDs; the latter differences correlate with the biophysical observations.

Structural basis of metallo-ß-lactamase, serine-ß-lactamase and penicillin-binding protein inhibition by cyclic boronates.

ß-Lactamases enable resistance to almost all ß-lactam antibiotics. Pioneering work revealed that acyclic boronic acids can act as 'transition state analogue' inhibitors of nucleophilic serine enzymes, including serine-ß-lactamases. Here we report biochemical and biophysical analyses revealing that cyclic boronates potently inhibit both nucleophilic serine and zinc-dependent ß-lactamases by a mechanism involving mimicking of the common tetrahedral intermediate. Cyclic boronates also potently inhibit the non-essential penicillin-binding protein PBP 5 by the same mechanism of action. The results open the way for development of dual action inhibitors effective against both serine- and metallo-ß-lactamases, and which could also have antimicrobial activity through inhibition of PBPs.