A Cross-Sectional Study of Antibiotic Prescribing for Childhood Upper Respiratory Tract Infections in Irish General Practice

Introduction This study aimed to analyse antibiotic prescribing in cases of upper respiratory tract infection (URTI) in children under 6 years attending Irish daytime and out-of-hours General Practice (GP) services. There have been large scale changes in entitlements for free GP care for this group in recent years. Methods A cross-sectional study of children under 6 years with URTI presentations was performed, over a two-week period for three years from 2015 to 2017. Factors associated with antibiotic prescription and preferred antibiotic compliance were examined using multivariate logistic regression. Results 1,007 Under-6 patients presented with an URTI in our sample over the study period. Following introduction of free GP care, patients were 50% less likely to receive an antibiotic prescription. Overall antibiotic prescribing fell from 70% to 50% in daytime services and from 72% to 60% in the out-of-hours setting. Patients presenting to out-of-hours services were more likely to receive an antibiotic (OR: 1.42) and less likely to receive a deferred antibiotic (OR: 0.53). One quarter to one third of all prescriptions were for deferred antibiotics. Year-on-year trends showed a 13% decrease in prescriptions and 13% increase in preferred antibiotic use. Conclusion The introduction of free GP care led to significant reductions in antibiotic prescribing, which may be due to changes in health seeking behaviour by parents or other reasons. Antibiotic prescribing was more commonplace in the out-of-hours setting, and rates remains high by international standards. This study underlines the importance of ongoing work around GP antimicrobial stewardship, particularly in the out-of-hours setting.</p

Alpha-1 antitrypsin augmentation inhibits proteolysis of neutrophil membrane voltage-gated proton channel-1 in alpha-1 deficient individuals

Background and Objectives: Alpha-1 antitrypsin is a serine protease inhibitor that demonstrates an array of immunomodulatory functions. Individuals with the genetic condition of alpha-1 antitrypsin deficiency (AATD) are at increased risk of early onset emphysematous lung disease. This lung disease is partly driven by neutrophil mediated lung destruction in an environment of low AAT. As peripheral neutrophil hyper-responsiveness in AATD leads to excessive degranulation and increased migration to the airways, we examined the expression of the membrane voltage-gated proton channel-1 (HVCN1), which is integrally linked to neutrophil function. The objectives of this study were to evaluate altered HVCN1 in AATD neutrophils, serine protease-dependent degradation of HVCN1, and to investigate the ability of serum AAT to control HVCN1 expression. Materials and Methods: Circulating neutrophils were purified from AATD patients (n = 20), AATD patients receiving AAT augmentation therapy (n = 3) and healthy controls (n = 20). HVCN1 neutrophil expression was assessed by flow cytometry and Western blot analysis. Neutrophil membrane bound elastase was measured by fluorescence resonance energy transfer. Results: In this study we demonstrated that HVCN1 protein is under-expressed in AATD neutrophils (p = 0.02), suggesting a link between reduced HVCN1 expression and AAT deficiency. We have demonstrated that HVCN1 undergoes significant proteolytic degradation in activated neutrophils (p p = 0.0004). In addition, the treatment of AATD individuals with AAT augmentation therapy increased neutrophil plasma membrane HVCN1 expression (p = 0.01). Conclusions: Our results demonstrate reduced levels of HVCN1 in peripheral blood neutrophils that may influence the neutrophil-dominated immune response in the AATD airways and highlights the role of antiprotease treatment and specifically AAT augmentation therapy in protecting neutrophil membrane expression of HVCN1.</div

Alpha-1 antitrypsin augmentation inhibits proteolysis of neutrophil membrane voltage-gated proton channel-1 in alpha-1 deficient individuals

Background and Objectives: Alpha-1 antitrypsin is a serine protease inhibitor that demonstrates an array of immunomodulatory functions. Individuals with the genetic condition of alpha-1 antitrypsin deficiency (AATD) are at increased risk of early onset emphysematous lung disease. This lung disease is partly driven by neutrophil mediated lung destruction in an environment of low AAT. As peripheral neutrophil hyper-responsiveness in AATD leads to excessive degranulation and increased migration to the airways, we examined the expression of the membrane voltage-gated proton channel-1 (HVCN1), which is integrally linked to neutrophil function. The objectives of this study were to evaluate altered HVCN1 in AATD neutrophils, serine protease-dependent degradation of HVCN1, and to investigate the ability of serum AAT to control HVCN1 expression. Materials and Methods: Circulating neutrophils were purified from AATD patients (n = 20), AATD patients receiving AAT augmentation therapy (n = 3) and healthy controls (n = 20). HVCN1 neutrophil expression was assessed by flow cytometry and Western blot analysis. Neutrophil membrane bound elastase was measured by fluorescence resonance energy transfer. Results: In this study we demonstrated that HVCN1 protein is under-expressed in AATD neutrophils (p = 0.02), suggesting a link between reduced HVCN1 expression and AAT deficiency. We have demonstrated that HVCN1 undergoes significant proteolytic degradation in activated neutrophils (p p = 0.0004). In addition, the treatment of AATD individuals with AAT augmentation therapy increased neutrophil plasma membrane HVCN1 expression (p = 0.01). Conclusions: Our results demonstrate reduced levels of HVCN1 in peripheral blood neutrophils that may influence the neutrophil-dominated immune response in the AATD airways and highlights the role of antiprotease treatment and specifically AAT augmentation therapy in protecting neutrophil membrane expression of HVCN1.</div

Musculoskeletal Clinical Vignettes: a case based text

Musculoskeletal conditions are an extremely common presentation to general practitioners, emergency departments and hospitals. Although the clinical examination for each joint involves a similar approach (the ‘Look, Feel, Move’ format), be it the shoulder, hip or knee, many students can find the subtle differences between each examination difficult. They may also struggle to generate an appropriate differential diagnosis, based upon the history and examination. Commonly presenting musculoskeletal conditions in general practice and orthopaedics are presented in the form of clinical vignettes in this document. Each vignette starts by summarising the typical history and examination findings for each condition. The main positive clinical examination findings are outlined in bold and other possible findings in normal font. A list of differential diagnoses are then given followed by sub-headings illustrating why one diagnosis is more likely and others less so for each case. Appropriate investigations and management for the general practitioner or orthopaedic surgeon are listed to complete each vignette</p

Effect of elexacaftor / tezacaftor / ivacaftor on airway and systemic inflammation in cystic fibrosis

Treatment with elexacaftor/tezacaftor/ivacaftor (ETI) has been shown to improve lung function in people with cystic fibrosis (PWCF). However, its biological effects remain incompletely understood. Here we describe alterations in pulmonary and systemic inflammation in PWCF following initiation of ETI. To address this, we collected spontaneously expectorated sputum and matching plasma from PWCF (n=30) immediately prior to ETI therapy, then again at 3 and 12 months. Within 3 months, PWCF demonstrated reduced activity of neutrophil elastase, proteinase three and cathepsin G, and decreased concentrations of interleukin (IL)-1β and IL-8 in sputum, accompanied by decreased Pseudomonas burden and restoration of secretory leukoprotease inhibitor levels. Once treated with ETI, all airway inflammatory markers studied in PWCF had reduced to levels found in matched non-CF bronchiectasis controls. In PWCF with advanced disease, ETI resulted in decreased plasma concentrations of IL-6, C-reactive protein and soluble TNF receptor one as well as normalisation of levels of the acute phase protein, alpha-1 antitrypsin. These data clarify the immunomodulatory effects of ETI and underscore its role as a disease modifier. </p

Activation of complement component 3 is associated with airways disease and pulmonary emphysema in alpha-1 antitrypsin deficiency

Introduction: Alpha-1 antitrypsin (AAT) deficiency (AATD) is associated with early onset emphysema. The aim of this study was to investigate whether AAT binding to plasma constituents could regulate their activation, and in AATD, exploit this binding event to better understand the condition and uncover novel biomarkers of therapeutic efficacy.Methods: To isolate AAT linker proteins, plasma samples were separated by size exclusion chromatography, followed by co-immunoprecipitation. AAT binding proteins were identified by mass spectrometry. Complement turnover and activation was determined by ELISA measurement of C3, C3a and C3d levels in plasma of healthy controls (n=15), AATD (n=51), non-AATD patients with obstructive airway disease (n=10) and AATD patients post AAT augmentation therapy (n=5).Results: Direct binding of complement C3 to AAT was identified in vivo and in vitro. Compared with healthy controls, a breakdown product of C3, C3d, was increased in AATD (0.04 µg/mL vs 1.96 µg/mL, p=0.0002), with a significant correlation between radiographic pulmonary emphysema and plasma levels of C3d (R2=0.37, p=0.001). In vivo, AAT augmentation therapy significantly reduced plasma levels of C3d in comparison to patients not receiving AAT therapy (0.15 µg/mL vs 2.18 µg/mL, respectively, p=0.001).Discussion: Results highlight the immune-modulatory impact of AAT on the complement system, involving an important potential role for complement activation in disease pathogenesis in AATD. The association between plasma C3d levels and pulmonary disease severity, that decrease in response to AAT augmentation therapy, supports the exploration of C3d as a candidate biomarker of therapeutic efficacy in AATD.</p

C3d elicits neutrophil degranulation and decreases endothelial cell migration, with implications for patients with alpha-1 antitrypsin deficiency

Alpha-1 antitrypsin (AAT) deficiency (AATD) is characterized by increased risk for emphysema, chronic obstructive pulmonary disease (COPD), vasculitis, and wound-healing impairment. Neutrophils play a central role in the pathogenesis of AATD. Dysregulated complement activation in AATD results in increased plasma levels of C3d. The current study investigated the impact of C3d on circulating neutrophils. Blood was collected from AATD (n = 88) or non-AATD COPD patients (n = 10) and healthy controls (HC) (n = 40). Neutrophils were challenged with C3d, and degranulation was assessed by Western blotting, ELISA, or fluorescence resonance energy transfer (FRET) substrate assays. Ex vivo, C3d levels were increased in plasma (p p = 0.038) in AATD compared to HC. C3d binding to CR3 receptors triggered primary (p = 0.01), secondary (p = 0.004), and tertiary (p = 0.018) granule release and increased CXCL8 secretion (p = 0.02). Ex vivo plasma levels of bactericidal-permeability-increasing-protein (p = 0.02), myeloperoxidase (p p p p < 0.0001). In summary, AATD patients had increased C3d in plasma and on neutrophil membranes and, together with neutrophil-released granule enzymes, reduced endothelial cell migration and wound healing, with potential implications for AATD-related vasculitis. </p

Safety and reactogenicity of coronavirus disease 2019 vaccination in severe alpha-1 antitrypsin deficiency

Background: Patients with alpha-1 antitrypsin deficiency (AATD) exhibit dysregulated inflammatory responses and a predilection for autoimmunity. While the adverse event (AE) profiles of COVID-19 vaccines in several chronic inflammatory conditions are now available, safety and tolerability data for patients with severe AATD have yet to be described. The feasibility of coadministering vaccines against COVID-19 and influenza in this population is similarly unclear. Methods: We conducted a prospective study of 170 patients with Pi*ZZ genotype AATD receiving their initial vaccination series with ChAdOx1 nCoV-19 (AstraZeneca). Patients were monitored clinically for AEs over the week that followed their first and second doses. In parallel, we conducted the same assessments in patients with Pi*MM genotype chronic obstructive pulmonary disease (COPD) (n=160) and Pi*MM individuals without lung disease (n=150). The Pi*ZZ cohort was subsequently followed through 2 consecutive mRNA-based booster vaccines (monovalent and bivalent BNT162b2, Pfizer/BioNTech). To assess the safety of combined vaccination against COVID-19 and influenza, the quadrivalent influenza vaccine was administered to participants attending for their second COVID-19 booster vaccination, either on the same day or following a 1-week interval. Results: Pi*ZZ AATD participants did not display increased AEs compared to Pi*MM COPD or Pi*MM non-lung disease controls. Although unexpected and serious vaccine-associated AEs did occur, the majority of AEs experienced across the 3 groups were mild and self-limiting. The AATD demographic at highest risk for AEs (especially systemic and prolonged AEs) was young females. No increase in AE risk was observed in patients with established emphysema, sonographic evidence of liver disease, or in those receiving intravenous augmentation therapy. AE incidence declined sharply following the initial vaccine series. Same-day coadministration of the COVID-19 mRNA bivalent booster vaccine and the annual influenza vaccine did not result in increased AEs compared to sequential vaccines 1 week apart. Conclusions: Despite their pro-inflammatory state, patients with severe AATD are not at increased risk of AEs or serious AEs compared to patients with nonhereditary COPD and patients without lung disease. Same-day coadministration of COVID-19 booster vaccines with the annual influenza vaccine is feasible, safe, and well-tolerated in this population.</div

<i>In vitro</i> and <i>in vivo</i> modulation of NADPH oxidase activity and reactive oxygen species production in human neutrophils by α1-antitrypsin.

Oxidative stress from innate immune cells is a driving mechanism that underlies COPD pathogenesis. Individuals with α-1 antitrypsin (AAT) deficiency (AATD) have a dramatically increased risk of developing COPD. To understand this further, the aim of this study was to investigate whether AATD presents with altered neutrophil NADPH oxidase activation, due to the specific lack of plasma AAT. Experiments were performed using circulating neutrophils isolated from healthy controls and individuals with AATD. Superoxide anion (O2 -) production was determined from the rate of reduction of cytochrome c. Quantification of membrane NADPH oxidase subunits was performed by mass spectrometry and Western blot analysis. The clinical significance of our in vitro findings was assessed in patients with AATD and severe COPD receiving intravenous AAT replacement therapy. In vitro, AAT significantly inhibited O2 - production by stimulated neutrophils and suppressed receptor stimulation of cyclic adenosine monophosphate and extracellular signal-regulated kinase (ERK)1/2 phosphorylation. In addition, AAT reduced plasma membrane translocation of cytosolic phox components of the NADPH oxidase. Ex vivo, AATD neutrophils demonstrated increased plasma membrane-associated p67phox and p47phox and significantly increased O2 - production. The described variance in phox protein membrane assembly was resolved post-AAT augmentation therapy in vivo, the effects of which significantly reduced AATD neutrophil O2 - production to that of healthy control cells. These results expand our knowledge on the mechanism of neutrophil-driven airways disease associated with AATD. Therapeutic AAT augmentation modified neutrophil NADPH oxidase assembly and reactive oxygen species production, with implications for clinical use in conditions in which oxidative stress plays a pathogenic role. </p

<i>In vitro</i> and <i>in vivo</i> modulation of NADPH oxidase activity and reactive oxygen species production in human neutrophils by α1-antitrypsin.

Oxidative stress from innate immune cells is a driving mechanism that underlies COPD pathogenesis. Individuals with α-1 antitrypsin (AAT) deficiency (AATD) have a dramatically increased risk of developing COPD. To understand this further, the aim of this study was to investigate whether AATD presents with altered neutrophil NADPH oxidase activation, due to the specific lack of plasma AAT. Experiments were performed using circulating neutrophils isolated from healthy controls and individuals with AATD. Superoxide anion (O2 -) production was determined from the rate of reduction of cytochrome c. Quantification of membrane NADPH oxidase subunits was performed by mass spectrometry and Western blot analysis. The clinical significance of our in vitro findings was assessed in patients with AATD and severe COPD receiving intravenous AAT replacement therapy. In vitro, AAT significantly inhibited O2 - production by stimulated neutrophils and suppressed receptor stimulation of cyclic adenosine monophosphate and extracellular signal-regulated kinase (ERK)1/2 phosphorylation. In addition, AAT reduced plasma membrane translocation of cytosolic phox components of the NADPH oxidase. Ex vivo, AATD neutrophils demonstrated increased plasma membrane-associated p67phox and p47phox and significantly increased O2 - production. The described variance in phox protein membrane assembly was resolved post-AAT augmentation therapy in vivo, the effects of which significantly reduced AATD neutrophil O2 - production to that of healthy control cells. These results expand our knowledge on the mechanism of neutrophil-driven airways disease associated with AATD. Therapeutic AAT augmentation modified neutrophil NADPH oxidase assembly and reactive oxygen species production, with implications for clinical use in conditions in which oxidative stress plays a pathogenic role. </p