Consensus criteria for chronic rhinosinusitis disease control: an international Delphi Study.

BACKGROUND: Chronic rhinosinusitis (CRS) disease control is a global metric of disease status for CRS. While there is broad acceptance that it is an important treatment goal, there has been inconsistency in the criteria used to define CRS control. The objective of this study was to identify and develop consensus around essential criteria for assessment of CRS disease control. METHODS: Modified Delphi methodology consisting of three rounds to review a list of 24 possible CRS control criteria developed by a 12-person steering committee. The core authorship of the multidisciplinary EPOS 2020 guidelines was invited to participate. RESULTS: Thirty-two individuals accepted the invitation to participate and there was no dropout of participants throughout the entire study (3 rounds). Consensus essential criteria for assessment of CRS control were: overall symptom severity, need for CRS-related systemic corticosteroids in the prior 6 months, severity of nasal obstruction, and patient-reported CRS control. Near-consensus items were: nasal endoscopy findings, severity of smell loss, overall quality of life, impairment of normal activities and severity of nasal discharge. Participants’ comments provided insights into caveats of, and disagreements related to, near-consensus items. CONCLUSIONS: Overall symptom severity, use of CRS-related systemic corticosteroids, severity of nasal obstruction, and patient-reported CRS control are widely agreed upon essential criteria for assessment of CRS disease control. Consideration of near-consensus items to assess CRS control should be implemented with their intrinsic caveats in mind. These identified consensus CRS control criteria, together with evidence-based support, will provide a foundation upon which CRS control criteria with wide-spread acceptance can be developed.

Position paper on olfactory dysfunction: 2023

BACKGROUND: Since publication of the original Position Paper on Olfactory Dysfunction in 2017 (PPOD-17), the personal and societal burden of olfactory disorders has come sharply into focus through the lens of the COVID-19 pandemic. Clinicians, scientists and the public are now more aware of the importance of olfaction, and the impact of its dysfunction on quality of life, nutrition, social relationships and mental health. Accordingly, new basic, translational and clinical research has resulted in significant progress since the PPOD-17. In this updated document, we present and discuss currently available evidence for the diagnosis and management of olfactory dysfunction. Major updates to the current version include, amongst others: new recommendations on olfactory related terminology; new imaging recommendations; new sections on qualitative OD and COVID-19 OD; updated management section. Recommendations were agreed by all co-authors using a modified Delphi process. CONCLUSIONS: We have provided an overview of current evidence and expert-agreed recommendations for the definition, investigation, and management of OD. As for our original Position Paper, we hope that this updated document will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency, and generalisability of work in this field.

Developing a core outcome set for clinical trials in olfactory disorders: a COMET initiative.

STATEMENT OF PROBLEM: Evaluating the effectiveness of the management of Olfactory Dysfunction (OD) has been limited by a paucity of high-quality randomised and/or controlled trials. A major barrier is heterogeneity of outcomes in such studies. Core outcome sets (COS) - standardized sets of outcomes that should be measured/reported as determined by consensus-would help overcome this problem and facilitate future meta-analyses and/or systematic reviews (SRs). We set out to develop a COS for interventions for patients with OD. METHODS: A long-list of potential outcomes was identified by a steering group utilising a literature review, thematic analysis of a wide range of stakeholders' views and systematic analysis of currently available Patient Reported Outcome Measures (PROMs). A subsequent e-Delphi process allowed patients and healthcare practitioners to individually rate the outcomes in terms of importance on a 9-point Likert scale. RESULTS: After 2 rounds of the iterative eDelphi process, the initial outcomes were distilled down to a final COS including subjective questions (visual analogue scores, quantitative and qualitative), quality of life measures, psychophysical testing of smell, baseline psychophysical testing of taste, and presence of side effects along with the investigational medicine/device and patient's symptom log. CONCLUSIONS: Inclusion of these core outcomes in future trials will increase the value of research on clinical interventions for OD. We include recommendations regarding the outcomes that should be measured, although future work will be required to further develop and revalidate existing outcome measures.

Commentary on Patient Advocacy and Research Priorities in Olfactory and Gustatory Disorders.

Purpose of Review: This paper outlines the challenges faced by people with smell and taste disorders (SATDs) and why patient advocacy is crucial in addressing these. It includes recent findings in identifying research priorities in SATDs. Recent Findings: A recent Priority Setting Partnership (PSP) conducted with the James Lind Alliance (JLA) has been completed and the top 10 research priorities in SATDs determined. Fifth Sense, a UK charity, has been working alongside patient and healthcare professions to drive awareness, education and research in this area. Summary: Following the completion of the PSP, Fifth Sense have launched six Research Hubs to take forward these priorities and engage with researchers to carry out and deliver research that directly answers the questions raised by the results of the PSP. The six Research Hubs cover a different aspect of smell and taste disorders. Each hub is led by clinicians and researchers recognised for their expertise in their field, who will act as champions for their respective hub.

Manipulation under anaesthesia of fractured nasal bones - a 10-year retrospective study.

BACKGROUND: Nasal bone fractures are treated by manipulation under general or local anaesthesia procedures. Data on long-term benefits of manipulation under local anaesthesia are limited. This study aimed to quantify the proportion of patients requiring septoplasty or septorhinoplasty after manipulation under general and local anaesthesia procedures. METHODS: Anonymised data were collected from electronic records of all patients who underwent manipulation under anaesthesia at our centre over a 10-year period, including demographics, manipulation under anaesthesia timing and further surgery requirements. RESULTS: The study identified 625 manipulation under general anaesthesia and 52 manipulation under local anaesthesia procedures. Manipulation under local anaesthesia procedures were performed earlier (local anaesthesia = 9 days, general anaesthesia = 15 days; p < 0.05) and were more likely to achieve manipulation (local anaesthesia = 83 per cent, general anaesthesia = 76 per cent; p < 0.05). There was no difference between techniques in the percentage of patients requiring further surgery. CONCLUSION: This paper describes a large cohort of patients who underwent manipulation under anaesthesia over a 10-year period. Manipulation under local anaesthesia procedures have increased since the coronavirus disease 2019 pandemic, and the results are comparable to manipulation under general anaesthesia, with reduced delays between injury and manipulation.

The EUFOREA pocket guide for chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is known to affect around 5 % of the total population, with major impact on the quality of life of those severely affected (1). Despite a substantial burden on individuals, society and health economies, CRS often remains underdiagnosed, under-estimated and under-treated (2). International guidelines like the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) (3) and the International Consensus statement on Allergy and Rhinology: Rhinosinusitis 2021 (ICAR) (4) offer physicians insight into the recommended treatment options for CRS, with an overview of effective strategies and guidance of diagnosis and care throughout the disease journey of CRS.

The COVANOS trial - insight into post-COVID olfactory dysfunction and the role of smell training.

BACKGROUND: Olfactory dysfunction is a cardinal symptom of COVID-19 infection, however, studies assessing long-term olfactory dysfunction are limited and no randomised-controlled trials (RCTs) of early olfactory training have been conducted. METHODOLOGY: We conducted a prospective, multi-centre study consisting of baseline psychophysical measurements of smell and taste function. Eligible participants were further recruited into a 12-week RCT of olfactory training versus control (safety information). Patient-reported outcomes were measured using an electronic survey and BSIT at baseline and 12 weeks. An additional 1-year follow-up was open to all participants. RESULTS: 218 individuals with a sudden loss of sense of smell of at least 4-weeks were recruited. Psychophysical smell loss was observed in only 32.1%; 63 participants were recruited into the RCT. The absolute difference in BSIT improvement after 12 weeks was 0.45 higher in the intervention arm. 76 participants completed 1-year follow-up; 10/19 (52.6%) of participants with an abnormal baseline BSIT test scored below the normal threshold at 1-year, and 24/29 (82.8%) had persistent parosmia. CONCLUSIONS: Early olfactory training may be helpful, although our findings are inconclusive. Notably, a number of individuals who completed the 1-year assessment had persistent smell loss and parosmia at 1-year. As such, both should be considered important entities of long-Covid and further studies to improve management are highly warranted.

A follow-up on quantitative and qualitative olfactory dysfunction and other symptoms in patients recovering from COVID-19 smell loss.

BACKGROUND: Sudden smell loss is a specific early symptom of COVID-19, which, prior to the emergence of Omicron, had estimated prevalence of ~40% to 75%. Chemosensory impairments affect physical and mental health, and dietary behavior. Thus, it is critical to understand the rate and time course of smell recovery. The aim of this cohort study was to characterize smell function and recovery up to 11 months post COVID-19 infection. METHODS: This longitudinal survey of individuals suffering COVID-19-related smell loss assessed disease symptoms and gustatory and olfactory function. Participants (n=12,313) who completed an initial survey (S1) about respiratory symptoms, chemosensory function and COVID-19 diagnosis between April and September 2020, were invited to complete a follow-up survey (S2). Between September 2020 and February 2021, 27.5% participants responded (n=3,386), with 1,468 being diagnosed with COVID-19 and suffering co-occurring smell and taste loss at the beginning of their illness. RESULTS: At follow-up (median time since COVID-19 onset ~200 days), ~60% of women and ~48% of men reported less than 80% of their pre-illness smell ability. Taste typically recovered faster than smell, and taste loss rarely persisted if smell recovered. Prevalence of parosmia and phantosmia was ~10% of participants in S1 and increased substantially in S2: ~47% for parosmia and ~25% for phantosmia. Persistent smell impairment was associated with more symptoms overall, suggesting it may be a key marker of long-COVID illness. The ability to smell during COVID-19 was rated slightly lower by those who did not eventually recover their pre-illness ability to smell at S2. CONCLUSIONS: While smell ability improves for many individuals who lost it during acute COVID-19, the prevalence of parosmia and phantosmia increases substantially over time. Olfactory dysfunction is associated with broader persistent symptoms of COVID-19, and may last for many months following acute COVID-19. Taste loss in the absence of smell loss is rare. Persistent qualitative smell symptoms are emerging as common long-term sequelae; more research into treatment options is strongly warranted given that even conservative estimates suggest millions of individuals may experience parosmia following COVID-19. Healthcare providers worldwide need to be prepared to treat post COVID-19 secondary effects on physical and mental health.

Comparison of COVID-19 and common cold chemosensory dysfunction.

Anosmia constitutes a prominent symptom of COVID-19. However, anosmia is also a common symptom of acute colds of various origins. In contrast to an acute cold, it appears from several questionnaire-based studies that in the context of COVID-19 infection, anosmia is the main rhinological symptom and is usually not associated with other rhinological symptoms such as rhinorrhoea or nasal obstruction. Until now, no study has directly compared smell and taste function between COVID-19 patients and patients with other causes of upper respiratory tract infection (URTI) using valid and reliable psychophysical tests. In this study, we aimed to objectively assess and compare olfactory and gustatory functions in 10 COVID-19 patients (PCR diagnosed, assessed on average 2 weeks after infection), 10 acute cold (AC) patients (assessed before the COVID-19 outbreak) and 10 healthy controls, matched for age and sex. Smell performance was assessed using the extended "Sniffin' Sticks" test battery (4), while taste function was assessed using "taste strips" (5). Receiver Operating Characteristic (ROC) curves were built to probe olfactory and gustatory scores in terms of their discrimination between COVID-19 and AC patients. Our results suggest that mechanisms of COVID-19 related olfactory dysfunction are different from those seen in an AC and may reflect, at least to some extent, a specific involvement at the level of central nervous system in some COVID-19 patients. In the future, studies to assess the prevalence of persistent anosmia and neuroanatomical changes on MRI correlated to chemosensory function, will be useful to understand these mechanisms.

Anosmia as a presenting symptom of SARS-CoV-2 infection in healthcare workers - A systematic review of the literature, case series, and recommendations for clinical assessment and management.

BACKGROUND: Healthcare workers are at the forefront of the ongoing COVID-19 pandemic and are at high risk for both the contraction and subsequent spread of virus. Understanding the role of anosmia as an early symptom of infection may improve monitoring and management of SARS-CoV2 infection. METHODOLOGY: We conducted a systematic review of the literature of SARS-CoV2 infection/COVID-19 and anosmia to help inform management of anosmia in healthcare works. We report a case series of healthcare workers, who presented with a loss of sense of smell secondary to COVID-19 infection to demonstrate management principles. RT-PCR was used to confirm COVID-19 positivity and psychophysical testing of olfaction was performed using the British version of the University of Pennsylvania Smell Identification Test, UPSIT. RESULTS: The systematic literature search returned 31 articles eligible for inclusion in the study and informed our recommendations for clinical assessment and management. All three healthcare professionals who presented with loss of sense of smell subsequently tested positive for SARS-CoV-2. Psychophysical testing of olfaction using the UPSIT confirmed mild and moderate microsmia in two, respectively, and normosmia at day 17 in one. CONCLUSIONS: Olfactory (± gustatory) dysfunction is indicative of COVID-19 infection and thus has important implications in the context of healthcare workers, or key workers in general, who work in close contact with others if not recognised as suffering from COVID. This leads to a potentially higher likelihood of spreading the virus. In conjunction with our literature review these findings have helped with creating recommendations on the assessment and management of olfactory dysfunction during the ongoing COVID-19 pandemic, both for healthcare workers and patients.

The socioeconomic cost of chronic rhinosinusitis study.

INTRODUCTION: Chronic rhinosinusitis (CRS) is highly prevalent, affecting 11% of the population. Studies evaluating the socio-economic impact of CRS are mostly limited to the US population. Currently there is no study that has evaluated the socio-economic costs of CRS in the UK. METHODS: A case-control study of patients with CRS and healthy controls was conducted to investigate the wider socio-economic impact of the disease. Data on demographic and socioeconomic characteristics, out-of-pocket expenditure (OOPE), health resource utilisation, productivity losses and health-related quality of life (HRQoL) via the EQ-5D and SNOT-22 instruments, were collected from questionnaires. RESULTS: A total of 139 CRS participants and 67 control participants completed the questionnaires. The average total OOPE per patient extrapolated to a 12-month period was £304.84. Other important findings include significantly higher reported primary care interactions (4.14 vs. 1.16) as well as secondary care interactions (2.61 vs 0.4) in CRS group as compared to controls over three-months. The average total missed workdays was estimated to be 18.7 per patient per year. The estimated incremental healthcare cost of CRS per year is £16.8 billion or £2.8 billion per million inhabitants. Factors predictive of a higher OOPE include higher household occupancy and income and these accounted for only 9.7% of the total variance in total OOPEs. Other socioeconomic, demographic and HRQoL variables were not found to be predictive factors of OOPE. CONCLUSIONS: This study showed that CRS has a significant wider economic burden beyond the immediate direct healthcare costs. CRS participants had a high level of healthcare service use, OOPE and productivity loss. Results from this study will add to the existing limited data both for the UK and abroad and emphasises the need for effective treatments for these patients to reduce the disease impact.

European Position Paper on Rhinosinusitis and Nasal Polyps 2020.

The European Position Paper on Rhinosinusitis and Nasal Polyps 2020 is the update of similar evidence based position papers published in 2005 and 2007 and 2012. The core objective of the EPOS2020 guideline is to provide revised, up-to-date and clear evidence-based recommendations and integrated care pathways in ARS and CRS. EPOS2020 provides an update on the literature published and studies undertaken in the eight years since the EPOS2012 position paper was published and addresses areas not extensively covered in EPOS2012 such as paediatric CRS and sinus surgery. EPOS2020 also involves new stakeholders, including pharmacists and patients, and addresses new target users who have become more involved in the management and treatment of rhinosinusitis since the publication of the last EPOS document, including pharmacists, nurses, specialised care givers and indeed patients themselves, who employ increasing self-management of their condition using over the counter treatments. The document provides suggestions for future research in this area and offers updated guidance for definitions and outcome measurements in research in different settings. EPOS2020 contains chapters on definitions and classification where we have defined a large number of terms and indicated preferred terms. A new classification of CRS into primary and secondary CRS and further division into localized and diffuse disease, based on anatomic distribution is proposed. There are extensive chapters on epidemiology and predisposing factors, inflammatory mechanisms, (differential) diagnosis of facial pain, allergic rhinitis, genetics, cystic fibrosis, aspirin exacerbated respiratory disease, immunodeficiencies, allergic fungal rhinosinusitis and the relationship between upper and lower airways. The chapters on paediatric acute and chronic rhinosinusitis are totally rewritten. All available evidence for the management of acute rhinosinusitis and chronic rhinosinusitis with or without nasal polyps in adults and children is systematically reviewed and integrated care pathways based on the evidence are proposed. Despite considerable increases in the amount of quality publications in recent years, a large number of practical clinical questions remain. It was agreed that the best way to address these was to conduct a Delphi exercise . The results have been integrated into the respective sections. Last but not least, advice for patients and pharmacists and a new list of research needs are included. The full document can be downloaded for free on the website of this journal: http://www.rhinologyjournal.com.

Antibiotic usage in chronic rhinosinusitis: analysis of national primary care electronic health records.

BACKGROUND: The aim of this study was to analyse rates of antibiotic usage in chronic rhinosinusitis (CRS) in primary care in England and Wales and to identify trends in the choice of antibiotics prescribed. METHODS: We used linked data from primary care EHRs, with diagnoses coded using the Read terminology (Clinical Practice Research Datalink) from consenting general practices, with (2) hospital care administrative records (Hospital Episode Statistics, HES recorded using ICD-10). RESULTS: From the total of 88,317 cases of CRS identified, 40,462 (46%) had an antibiotic prescription within 5 days of their first CRS diagnosis. Of patients receiving a first line antibiotic within 5 days of CRS diagnosis, over 80%, in each CRS group, received a subsequent prescription for an antibiotic. Within 5 years of diagnosis, 9% are estimated to have had 5 or more antibiotics within 5 days of a CRS-related consultation. With data spanning almost 20 years, it was possible to discern trends in antibiotics prescriptions, with a clear increasing trend towards macrolide and tetracycline prescribing evident. CONCLUSIONS: While antibiotics may have been prescribed for acute exacerbations, we have found high rates of repeated antibiotic prescription in some patients with CRS in primary care. There is a need for stronger evidence on the role of antibiotics in CRS management.

Optimising trial outcomes and patient retention for the MACRO trial for chronic rhinosinusitis.

BACKGROUND: This study aimed to evaluate current subjective and objective outcome assessments for the MACRO (defining best Management for Adults with Chronic RhinOsinusitis) Trial which compares antibiotics, placebo and sinus surgery. This was to identify any redundant assessments and to include patient perspectives to determine acceptability for confirmation in the trial. METHODS: Adults CRS patients meeting the provisional eligibility criteria for the MACRO trial were recruited to this mixed-method study at 2 sites. Correlations between the objective outcome measures and SNOT-22 scores were evaluated. Selected participants took part in a semi-structured telephone interview to explore their experiences and views of undergoing outcome measures. RESULTS: Seventy patients (37% male) were recruited, 36 had CRS without nasal polyps, 34 had CRS with nasal polyps. There was a weak inverse correlation between the SNOT-22 â€Blockage†ratings and Peak Nasal Inspiratory Flow readings, a moderate inverse correlation between the SNOT-22 â€Smell†ratings and Sniffin’ Sticks scores, but no significant correlation between the SNOT-22 and Saccharin test results. The participants’ experience of the trial visit was positive with an acceptable duration of trial visit. Most proposed outcome measures were valued by participants with the exception of the Saccharin test. DISCUSSION: The Sniffin’ Sticks test and PNIF correlate with their respective component SNOT-22 scores but are considered important by patients; PNIF is simple, cheap test to perform. The Saccharin test will be removed as participants did not value it and was not highly rated in parallel work on a core outcome set for CRS.

Exploring the association between ingestion of foods with higher potential salicylate content and symptom exacerbation in chronic rhinosinusitis. Data from the National Chronic Rhinosinusitis Epidemiology Study.

INTRODUCTION: Pharmacological salicylates are known to trigger respiratory exacerbations in patients with Non-Steroidal Exacerbated Respiratory Disease (N-ERD), a specific phenotype of Chronic Rhinosinusitis (CRS) and asthma. The impact of dietary sources of salicylates across subgroups of CRS is not well understood. The hypothesis is that in patients with nasal polyps present, there is likely to be a higher incidence of symptom exacerbation due to dietary salicylates regardless of any known response to pharmacological salicylate. METHODS: The Chronic Rhinosinusitis Epidemiology Study (CRES) was a questionnaire-based case-control study which sought to characterise the UK CRS population in terms of sociological, economic and medical factors. Using specific questions to examine participant responses relating to symptom exacerbation from food groups thought to be high in salicylate content, this analysis of the CRES database sought to compare an estimate of the prevalence of dietary sensitivity due to food with higher potential salicylate content across patients with CRS with (CRSwNPs) and without nasal polyposis (CRSsNPs) and with allergic fungal rhinosinusitis (AFRS). RESULTS: The CRSwNPs group were significantly more likely than controls to report symptom exacerbation due to ingestion of food groups with higher potential dietary salicylate content. The same trend was observed amongst CRSsNPs participants to a lesser degree. Reported response to the individual specific food groups wine, nuts, spicy foods, fruit and vegetables demonstrated that a statistically significant proportion of CRSwNPs and AFRS participants reported sensitivity to wine. CONCLUSIONS: This analysis suggests that there is an association between symptom exacerbation in response to food products with higher potential salicylate content, specifically wine, in CRS patients both with and without nasal polyposis when compared to controls, but especially in the CRSwNPs and AFRS phenotypes. Further studies are needed to detail if this relationship represents a causal relationship to dietary salicylate. The data present the possibility that a wider group of CRS patients may elicit salicylate sensitivity than those with known N-ERD.

Risk of mortality and cardiovascular events following macrolide prescription in chronic rhinosinusitis patients: a cohort study using linked primary care electronic health records.

BACKGROUND: Macrolide antibiotics have demonstrated important anti-inflammatory and immunomodulatory properties in chronic rhinosinusitis (CRS) patients. However, reports of increased risks of cardiovascular events have led to safety concerns. We investigated the risk of all-cause and cardiac death, and cardiovascular outcomes, associated with macrolide use. METHODOLOGY: Observational cohort (1997-2016) using linked data from the Clinical Practice Research Datalink, Hospital Episodes Statistics, and the Office for National Statistics. Patients aged 16-80 years with CRS prescribed a macrolide antibiotic or penicillin were included, comparing prescriptions for macrolide antibiotics to penicillin. Outcomes were all-cause mortality, cardiac death, myocardial infarction, stroke, diagnosis of peripheral vascular disease, and cardiac arrhythmia. RESULTS: Analysis included 320,798 prescriptions received by 66,331 patients. There were 3,251 deaths, 815 due to cardiovascular causes, 925 incident myocardial infarctions, 859 strokes, 637 diagnoses of peripheral vascular disease, and 1,436 cardiac arrhythmias. A non-statistically significant trend towards increased risk of myocardial infarction during the first 30 days following macrolide prescription was observed. No statistically significant short- or long-term risks were observed for macrolide prescription. No significant risks were identified for clarithromycin in particular. CONCLUSIONS: Although not statistically significant, our best estimates suggest an increased short-term risk of myocardial infarction in patients with CRS following macrolide prescription, supporting previous observational evidence. However, confounding by indication remains a possible explanation for this apparent increased risk. We found no evidence of longer term increased risks.

Unilateral visual loss resulting from orbital encroachment of an ethmoidal juvenile trabecular ossifying fibroma.

Ossifying fibromas are mainly found in the mandible and maxilla. Reports of them arising in the ethmoid sinuses and orbits are rare. We present a case of an otherwise healthy 20-year-old man with gradual onset of right visual disturbance signified by right relative afferent pupillary defect due to a large unilateral ossifying fibroma arising from the ethmoid sinus compressing the medial half of the right orbit. We emphasise the multidisciplinary combined endoscopic endonasal and external approach to ensure a successful debulking of the fibroma.

EPOS2020: development strategy and goals for the latest European Position Paper on Rhinosinusitis.

BACKGROUND: The European Position Papers on Rhinosinusitis from 2005, 2007 and 2012 have had a measurable impact on the way this common condition with high impact on quality of life is managed around the world. EPOS2020 will be the latest iteration of the guideline, addressing new stakeholders and target users, presenting a summary of the latest literature and evolving treatment modalities, and formulating clear recommendations based on all available evidence. METHODOLOGY: Based on the AGREE II framework, this article demonstrates how the EPOS2020 steering group will address six key areas to ensure consistency in quality and presentation of information in the latest rhinosinusitis clinical practice guideline: scope and purpose; stakeholder involvement; rigour of development; clarity of presentation; recommendations and applicability; editorial independence. RESULTS: By analysing the guidance from AGREE II, we formulated a detailed development strategy for EPOS2020. We identify new stakeholders and target users and ratify the importance of patient involvement in the latest EPOS guideline. New and expanded areas of research to be addressed are highlighted. We confirm our intention to use mixed methodologies, combining evidence-based medicine with real life studies; when no evidence can be found, use Delphi rounds to achieve clear, inclusive recommendations. We also introduce new concepts for dissemination of the guideline, using Internet and social media to improve accessibility. CONCLUSION: This article is an introduction to the EPOS2020 project, and presents the key goals, core stakeholders, planned methodology and dissemination strategies for the latest version of this influential guideline.

Iron catalysis of lipid peroxidation in ferroptosis: Regulated enzymatic or random free radical reaction?

Duality of iron as an essential cofactor of many enzymatic metabolic processes and as a catalyst of poorly controlled redox-cycling reactions defines its possible biological beneficial and hazardous role in the body. In this review, we discuss these two "faces" of iron in a newly conceptualized program of regulated cell death, ferroptosis. Ferroptosis is a genetically programmed iron-dependent form of regulated cell death driven by enhanced lipid peroxidation and insufficient capacity of thiol-dependent mechanisms (glutathione peroxidase 4, GPX4) to eliminate hydroperoxy-lipids. We present arguments favoring the enzymatic mechanisms of ferroptotically engaged non-heme iron of 15-lipoxygenases (15-LOX) in complexes with phosphatidylethanolamine binding protein 1 (PEBP1) as a catalyst of highly selective and specific oxidation reactions of arachidonoyl- (AA) and adrenoyl-phosphatidylethanolamines (PE). We discuss possible role of iron chaperons as control mechanisms for guided iron delivery directly to their "protein clients" thus limiting non-enzymatic redox-cycling reactions. We also consider opportunities of loosely-bound iron to contribute to the production of pro-ferroptotic lipid oxidation products. Finally, we propose a two-stage iron-dependent mechanism for iron in ferroptosis by combining its catalytic role in the 15-LOX-driven production of 15-hydroperoxy-AA-PE (HOO-AA-PE) as well as possible involvement of loosely-bound iron in oxidative cleavage of HOO-AA-PE to oxidatively truncated electrophiles capable of attacking nucleophilic targets in yet to be identified proteins leading to cell demise.