The Severe Heterogeneous Asthma Research collaboration, Patient-centred (SHARP) ERS Clinical Research Collaboration: a new dawn in asthma research

International Variation in Severe Exacerbation Rates in Patients With Severe Asthma

BACKGROUND

Exacerbation frequency strongly influences treatment choices in patients with severe asthma.

RESEARCH QUESTION

What is the extent of the variability of exacerbation rate across countries and its implications in disease management?

STUDY DESIGN AND METHODS

We retrieved data from the International Severe Asthma Registry, an international observational cohort of patients with a clinical diagnosis of severe asthma. We identified patients aged ≥ 18 years who did not initiate any biologics prior to baseline visit. A severe exacerbation was defined as the use of oral corticosteroids for ≥ 3 days or asthma-related hospitalization/ED visit. A series of negative binomial models were applied to estimate country-specific severe exacerbation rates during 365 days of follow-up, starting from a naive model with country as the only variable to an adjusted model with country as a random-effect term and patient and disease characteristics as independent variables.

RESULTS

The final sample included 7,510 patients from 17 countries (56% from the United States), contributing to 1,939 severe exacerbations (0.27/person-year). There was large between-country variation in observed severe exacerbation rate (minimum, 0.04 [Argentina]; maximum, 0.88 [Saudi Arabia]; interquartile range, 0.13-0.54), which remained substantial after adjusting for patient characteristics and sampling variability (interquartile range, 0.16-0.39).

INTERPRETATION

Individuals with similar patient characteristics but coming from different jurisdictions have varied severe exacerbation risks, even after controlling for patient and disease characteristics. This suggests unknown patient factors or system-level variations at play. Disease management guidelines should recognize such between-country variability. Risk prediction models that are calibrated for each jurisdiction will be needed to optimize treatment strategies.

Clinical Response and Remission in Patients With Severe Asthma Treated With Biologic Therapies

BACKGROUND

The development of novel targeted biologic therapies for severe asthma has provided an opportunity to consider remission as a new treatment goal.

RESEARCH QUESTION

How many patients with severe asthma treated with biologic therapy achieve clinical remission, and what predicts response to treatment?

STUDY DESIGN AND METHODS

The Danish Severe Asthma Register is a nationwide cohort including all adult patients receiving biologic therapy for severe asthma in Denmark. This observational cohort study defined "clinical response" to treatment following 12 months as a ≥ 50% reduction in exacerbations and/or a ≥ 50% reduction in maintenance oral corticosteroid dose, if required. "Clinical remission" was defined by cessation of exacerbations and maintenance oral corticosteroids, as well as a normalization of lung function (FEV1 > 80%) and a six-question Asthma Control Questionnaire score ≤ 1.5 following 12 months of treatment.

RESULTS

Following 12 months of treatment, 104 (21%) of 501 biologic-naive patients had no response to treatment, and 397 (79%) had a clinical response. Among the latter, 97 (24%) fulfilled the study criteria of clinical remission, corresponding to 19% of the entire population. Remission was predicted by shorter duration of disease and lower BMI in the entire population of patients treated with biologic therapy.

INTERPRETATION

Clinical response was achieved in most adult patients initiating biologic therapy, and clinical remission was observed in 19% of the patients following 12 months of treatment. Further studies are required to assess the long-term outcome of achieving clinical remission with biologic therapy.

Adult Severe Asthma Registries: A Global and Growing Inventory

Aim

The International Severe Asthma Registry (ISAR; http://isaregistries.org/) uses standardised variables to enable multi-country and adequately powered research in severe asthma. This study aims to look at the data countries within ISAR and non-ISAR countries reported collecting that enable global research that support individual country interests.

Methods

Registries were identified by online searches and approaching severe asthma experts. Participating registries provided data collection specifications or confirmed variables collected. Core variables (results from ISAR's Delphi study), steroid-related comorbidity variables, biologic safety variables (serious infection, anaphylaxis, and cancer), COVID-19 variables and additional variables (not belonging to the aforementioned categories) that registries reported collecting were summarised.

Results

Of the 37 registries identified, 26 were ISAR affiliates and 11 non-ISAR affiliates. Twenty-five ISAR-registries and 4 non-ISAR registries reported collecting >90% of the 65 core variables. Twenty-three registries reported collecting all optional steroid-related comorbidity variables. Twenty-nine registries reported collecting all optional safety variables. Ten registries reported collecting COVID-19 variables. Twenty-four registries reported collecting additional variables including data from asthma questionnaires (10 Asthma Control Questionnaire, 20 Asthma Control Test, 11 Asthma Quality of Life Questionnaire, and 4 EuroQol 5-dimension 5-level Questionnaire). Eight registries are linked to databases such as electronic medical records and national claims or disease databases.

Conclusion

Standardised data collection has enabled individual severe asthma registries to collect unified data and increase statistical power for severe asthma research irrespective of ISAR affiliations.

Characteristics of Severe Asthma Patients and Predictors of Asthma Control in the Swiss Severe Asthma Registry

BACKGROUND

Asthma is a chronic airway disease, affecting over 300 million people worldwide. 5-10% of patients suffer from severe asthma and account for 50% of asthma-related financial burden. Availability of real-life data about the clinical course of severe asthma is insufficient.

OBJECTIVES

The aims of this study were to characterize patients with severe asthma in Switzerland, enrolled in the Swiss Severe Asthma Registry (SSAR), and evaluate predictors for asthma control.

METHOD

A descriptive characterisation of 278 patients was performed, who were prospectively enrolled in the registry until January 2022. Socio-demographic variables, comorbidities, diagnostic values, asthma treatment, and healthcare utilisation were evaluated. Groups of controlled and uncontrolled asthma according to the asthma control test were compared.

RESULTS

Forty-eight percent of patients were female and the mean age was 55.8 years (range 13-87). The mean body mass index (BMI) was 27.4 kg/m2 (±6). 10.8% of patients were current smokers. Allergic comorbidities occurred in 54.3% of patients, followed by chronic rhinosinusitis (46.4%) and nasal polyps (34.1%). According to the ACT score, 54.7% had well controlled, 16.2% partly controlled and 25.9% uncontrolled asthma. The most common inhalation therapy was combined inhaled corticosteroids/long-acting β2-agonists (78.8%). Biologics were administered to 81.7% of patients and 19.1% received oral steroids. The multivariable analysis indicated that treatment with biologics was positively associated with asthma control whereas higher BMI, oral steroids, exacerbations, and COPD were negative predictors for asthma control.

CONCLUSION

Biologics are associated with improved control in severe asthma. Further studies are required to complete the picture of severe asthma in order to provide improved care for those patients.

Biologics in severe asthma: the role of real-world evidence from registries

Asthma is one of the most common noncommunicable diseases; in the majority of patients it is well controlled with inhaled bronchodilators and inhaled corticosteroids, but the management of severe asthma has been a significant challenge historically. The introduction of novel biologic drugs in the past few decades has revolutionised the field, presenting physicians with a variety of biologic drugs with different mechanisms for the treatment of severe asthma.It is of crucial importance to evaluate the effectiveness of these drugs by following their "real-life" effectiveness rather than relying solely on their efficacy, established in carefully designed clinical trials, which therefore do not necessarily match the profile of the real-life patient. Understanding the actual effectiveness of the specific drugs in real-life patients is a crucial part of tailoring the right drugs to the right patients. Registries serve as an important tool in obtaining real-life evidence, since they are in effect observational studies, following the entire patient population.

The effect of the COVID-19 pandemic on severe asthma care in Europe: will care change for good?

Background

The coronavirus disease 2019 (COVID-19) pandemic has put pressure on healthcare services, forcing the reorganisation of traditional care pathways. We investigated how physicians taking care of severe asthma patients in Europe reorganised care, and how these changes affected patient satisfaction, asthma control and future care.

Methods

In this European-wide cross-sectional study, patient surveys were sent to patients with a physician-diagnosis of severe asthma, and physician surveys to severe asthma specialists between November 2020 and May 2021.

Results

1101 patients and 268 physicians from 16 European countries contributed to the study. Common physician-reported changes in severe asthma care included use of video/phone consultations (46%), reduced availability of physicians (43%) and change to home-administered biologics (38%). Change to phone/video consultations was reported in 45% of patients, of whom 79% were satisfied or very satisfied with this change. Of 709 patients on biologics, 24% experienced changes in biologic care, of whom 92% were changed to home-administered biologics and of these 62% were satisfied or very satisfied with this change. Only 2% reported worsening asthma symptoms associated with changes in biologic care. Many physicians expect continued implementation of video/phone consultations (41%) and home administration of biologics (52%).

Conclusions

Change to video/phone consultations and home administration of biologics was common in severe asthma care during the COVID-19 pandemic and was associated with high satisfaction levels in most but not all cases. Many physicians expect these changes to continue in future severe asthma care, though satisfaction levels may change after the pandemic.

The German severe asthma patient: Baseline characteristics of patients in the German Severe Asthma Registry, and relationship with exacerbations and control

INTRODUCTION

The German Asthma Net Severe Asthma Registry is collecting long-term data from a large cohort of patients aged ≥6 years with severe asthma. This manuscript presents their baseline characteristics, and identifies relationships with exacerbations and/or poor asthma control.

METHODS

The registry is collecting routine clinical parameters including: demographics and medical history; disease characteristics (Asthma Control Questionnaire [ACQ]-5, forced expiratory volume in 1 s [FEV1]); exacerbations; and biomarkers (eosinophils, immunoglobulin E [IgE], fractional exhaled nitric oxide [FeNO]).

RESULTS

These analyses include data from 2011 patients at 72 sites (91.9% adult). Children (6-17 years) were more likely to be male, whereas more adults were female (males: children/adults 62%/41%). Most were receiving inhaled corticosteroid/long-acting β2-agonist combinations (78%/81%); 38.0% of adults were receiving systemic steroids. Asthma control was suboptimal in both groups: 21.5%/13.3% were controlled; 10.4%/49.1% were symptomatic; 33.1%/37.2% received emergency asthma treatment in the previous year. Median blood eosinophil (400/238 cells/μL) and IgE levels (494/186 IU/mL) were higher in children; FeNO was lower (19/35 ppb). Patients with ≥2 exacerbations in the previous year had lower FEV1 (absolute and % predicted) and IgE, and higher ACQ-5, FeNO and blood eosinophil levels (all p < 0.05). There was a weak, negative correlation between ACQ-5 and FEV1% predicted in adults (p < 0.001).

CONCLUSIONS

These analyses characterise the typical German patient with severe asthma, and provide information on their overall care. Their planned long-term follow-up will assess whether asthma control can be optimised, how best to do so, and most importantly how such optimisation can benefit patients.

The Korean Severe Asthma Registry (KoSAR): real world research in severe asthma

Severe asthma constitutes a serious health burden with significant morbidity and socioeconomic costs. The development and introduction of new biologics targeting type 2 inflammation changed the paradigm for management of severe asthma and initiated a biological era. These changes impose a challenge to clinicians in managing difficult-to-treat and severe asthma. To understand the characteristics and heterogeneity of severe asthma and to develop a better strategy to manage it, the Korean Academy of Asthma, Allergy and Clinical Immunology, Working Group on Severe Asthma, has organized the Korean Severe Asthma Registry (KoSAR). In this review, we describe the challenges of severe asthma management regarding diagnosis, disease burden, heterogeneity, guidelines, and organization of severe asthma clinics. This review also examines the current global activities of national and regional registries and study groups. In addition, we present the KoSAR vision and organization and describe the findings of KoSAR in comparison with those of other countries.

Use of Health Related Quality of Life in Clinical Trials for Severe Asthma: A Systematic Review

BACKGROUND

Asthma Health Related Quality of Life (HRQoL) is an outcome important to patients with severe asthma and can provide clinicians with additional insight into the benefits of treatment. The aim of this systematic review is to examine the use and reporting of HRQoL questionnaires within randomised controlled trials (RCTs) of biologics, fevipiprant and bronchial thermoplasty.

METHODS

We followed the guidelines on the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement. Of the 2380 retrieved articles, 52 studies were identified for inclusion.

RESULTS

Sixty-three percent included an asthma HRQoL questionnaire. It was a secondary outcome in the majority of cases (73%). The proportion of studies including an asthma HRQoL questionnaire did not change significantly over a 20-year period. While the Asthma Quality of Life Questionnaire (AQLQ) was used in 45% of studies, 55% used a variety of 4 questionnaires. Most (70%) of the studies that included a HRQoL questionnaire did not report its subscale scores. Approximately half (52%) of studies that used HRQoL reported this in the abstract of the paper. A higher proportion of studies used an asthma control questionnaire compared to a HRQoL questionnaire (71% vs 63%).

CONCLUSION

In order to increase the use of asthma HRQoL questionnaires in RCTs of severe asthma treatments, the drivers and barriers to their use must first be understood. At present, the patients' perspective is underrepresented in RCTs of biologics, fevipiprant and bronchial thermoplasty for severe asthma.

Attitudes of Croatian pulmonologists concerning obstacles to earlier, more appropriate use of biologics in severe asthma: Survey results

AIMS

Biologics have been proven efficacious for patients with severe asthma (SA). It is essential to diagnose such individuals correctly. This study was designed to survey pulmonologists to identify barriers to early diagnosis and subsequent appropriate use of biologics for SA in Croatia.

METHODS

A pulmonologist group with expertise in SA developed the initial list of questions, with the final questionnaire created according to a 2-round Delphi method. The resulting survey consisted of 23 items consequently divided into 4 domains: 1) Pulmonologists' demographics and professional experiences; 2) Concerns about asthma management; 3) Attitudes toward SA diagnosis; and 4) Beliefs and attitudes regarding the use of biologics in managing SA. The given answers represented the respondents' estimates.

RESULTS

Eighty-four surveys were analyzed, with pulmonologists observing that general practitioners often inaccurately diagnose asthma and treat acute exacerbations. Although specialist centers are capably and correctly equipped, the time to diagnose patients with SA is approximately 3.5 months, with initial use of biologics delayed an additional 2 months. The primary indications for prescribing biologics are conventional therapy with oral glucocorticoids (91.7%) and frequent acute exacerbations (82.1%). In addition to improper diagnosis (64.3%), many patients with SA do not receive the indicated biologics owing to strict administrative directives for reimbursement (70.2%) or limited hospital resources (57.1%).

LIMITATIONS

The limitations of this survey include the subjective nature of the collected data, the relatively small sample size, and the lack of the biologic efficacy evaluation.

CONCLUSIONS

Croatian pulmonologists observed that a significant number of patients with SA who are eligible for biologics are not prescribed them, largely because of an inaccurate and/or delayed diagnosis, a delayed referral to a specialist center, highly restrictive criteria for reimbursement, and/or institutional budgetary limitations.

SHARP: enabling generation of real-world evidence on a pan-European scale to improve the lives of individuals with severe asthma

Real-world evidence is important to help unravel unanswered problems in severe asthma and is valuable to better understand the patient experience and common clinical practice. The Severe Heterogeneous Asthma Registry, Patient-centred (SHARP) Clinical Research Collaboration is created as a network of national registries and severe asthma centres that work together to perform registry based real-world research and clinical studies on a pan-European scale. Such collaboration requires a new, innovative design to overcome the many issues that arise with large-scale data collection across national borders. SHARP has developed a platform that offers a federated analysis approach where national registry data are transformed and integrated into a common data model (CDM). The CDM then allows a local analysis of de-identified patient data and subsequent aggregate (meta-)analysis. To facilitate an easily accessible way to set up new registries, SHARP enables new registries to take part in a central database, based on already proven technology. Next to being economical, this linkage ensures data from different SHARP central members to be comparable. Technological advancements lead to an ever-expanding rate of patient data that will be collected; with the collective effort of the pan-European severe asthma research community SHARP hopes to ensure that they are well equipped to enter a new era of medical research, with the ultimate goal to positively impact the lives of patients with severe asthma.

Precision medicine in severe pediatric asthma: opportunities and challenges

Purpose of review

Severe pediatric asthma exerts a substantial burden on patients, their families and society. This review provides an update on the latest insights and needs regarding the implementation of precision medicine in severe pediatric asthma.

Recent findings

Biologicals targeting underlying inflammatory pathways are increasingly available to treat children with severe asthma, holding the promise to enable precision medicine in this heterogeneous patient population with high unmet clinical needs. However, the current understanding of which child would benefit from which type or combination of biologicals is still limited, as most evidence comes from adult studies and might not be generalizable to the pediatric population. Studies in pediatric severe asthma are scarce due to the time-consuming effort to diagnose severe asthma and the challenge to recruit sufficient study participants. The application of innovative systems medicine approaches in international consortia might provide novel leads for – preferably noninvasive – new biomarkers to guide precision medicine in severe pediatric asthma.

Summary

Despite the increased availability of targeted treatments for severe pediatric asthma, clinical decision-making tools to guide these therapies are still lacking for the individual pediatric patient.

Rasmussen L, D. Assing K, Wimmer-Aune A, B. Rasmussen K, Bjerring N, Christiansen A, Schmid J, Krogh NS, Porsbjerg C. The Danish severe asthma register: an electronic platform for severe asthma management and research

The evaluation and management of severe asthma patients require collection of comprehensive information, which is often a challenge in a busy outpatient clinic. The Danish Severe Asthma Register (DSAR) was designed as an electronic patient record form that captures operational clinical data and provides a clinical overview of the severe asthma patient. DSAR is a nationwide register; all patients in Denmark who are treated with biologics for severe asthma are included, and data are as a minimum entered at start of biological treatment, after four and 12 months of treatment, and hereafter annually. Currently, there are data from 621 treatment courses with biologics included in DSAR, with 71% of patients treated with anti-IL-5 drugs and 29% with an anti-IgE drug. Patients enter Patient Reported Outcome Measures electronically on tablets when they arrive in the outpatient clinic and their answers are immediately available to the clinician during the consultation. Nurses and doctors enter clinical data into DSAR during the consultation. DSAR offers immediate access to well-presented longitudinal overview and automatically creates a journal output that can be copy-pasted into the hospital's existing health record form. DSAR is also currently expanding with an app, to be used for monitoring of home-treatment. In addition to serving as an electronic patient record form, DSAR will also provide opportunities to monitor the real-life efficacy of biological treatment for severe asthma in Denmark, and it will be a valuable research platform that will aid in answering important research questions on severe asthma in the future.

Oral CorticoSteroid sparing with biologics in severe asthma: A remark of the Severe Asthma Network in Italy (SANI)

According to the data derived from several national and international registries, including SANI (Severe Asthma Network Italy), and considering the strong impact that frequent or regular use of oral corticosteroid has on quality of life (QoL) of severe asthmatics, as well as on the costs for managing corticosteroid-related diseases, oral corticosteroid sparing up to withdrawal should be considered a primary outcome in the management of severe asthma. New biologics have clearly demonstrated that this effect is possible, with concomitant reduction in the rate of exacerbations and in symptom control. Then, there is no reason for using so frequently oral corticosteroid before having explored all alternatives currently available for a large part of severe asthmatics.

Treatment Eligibility of Real-Life Mepolizumab-Treated Severe Asthma Patients

BACKGROUND

Patients with severe asthma not meeting the strict trial eligibility criteria for mepolizumab are now routinely treated with this biological in clinical practice, but it remains unclear whether these ineligible patients respond differently to mepolizumab treatment.

OBJECTIVE

This study investigated the extent and reasons for trial ineligibility of real-life, mepolizumab-treated patients with severe asthma and compared the characteristics of these patients with trial populations. Subsequently, therapeutic response in ineligible patients was assessed on the basis of oral corticosteroid (OCS) reduction.

METHODS

Trial eligibility, population differences, and therapeutic response were assessed using the baseline characteristics of mepolizumab-receiving patients with severe asthma treated in the Amsterdam University Medical Centres and OCS dose at 6 months for OCS-dependent patients extracted from patients' electronic health records. Eligibility criteria and population characteristics from trials investigating mepolizumab were extracted from their original publications.

RESULTS

A total of 82.4% of 119 mepolizumab-receiving, real-life patients with severe asthma were ineligible for trial inclusion, wherein 42.9% and 39.5% were excluded on the basis of inclusion and exclusion criteria, respectively. The clinical care population was older, more often male and demonstrating a better lung function under lower OCS maintenance dosages in comparison with trial populations. A total of 50% of 66 ineligible, OCS-dependent mepolizumab-treated patients were able to reduce their maintenance OCS dosage to ≤5 mg prednisone/day.

CONCLUSIONS

A large proportion of the real-life, mepolizumab-treated population with severe asthma would be excluded from trial participation, and significant differences in population characteristics exist. Regardless, a large fraction of ineligible patients in clinical care can reduce maintenance OCS dosage under mepolizumab therapy.

Sirtuin 1: Endocan and Sestrin 2 in Different Biological Samples in Patients with Asthma. Does Severity Make the Difference?

Background: Sestrin 2, Endocan, and Sirtuin 1 are distinct molecules with some biologic actions associated with asthma pathophysiology. The aim of the present study was to determine the molecular level differences attributable to underlying asthma severity. Methods: We initially recruited 85 asthmatics with a wide spectrum of severity. All of the patients were optimally treated according to current guidelines. Demographics, test results of lung function, and treatment regimes of all patients were recorded. Sestrin 2, Endocan, and Sirtuin 1 were measured in different biological samples (sputum with two processing methods and serum). Results: A total of 60 patients (35 with severe asthma) were analyzed, since 25 patients failed to produce an adequate sample of sputum. Patients with severe asthma showed significantly higher values for Sestrin 2 [pg/mL], measured in both sputum supernatant and cell pellet, compared to those with mild to moderate asthma [9524 (5696, 12,373) vs. 7476 (4265, 9273) p = 0.029, and 23,748 (15,280, 32,742) vs. 10,084 (3349, 21,784), p = 0.008, respectively]. No other significant differences were observed. No significant associations were observed between biomarkers, inflammatory cells, and lung function. Conclusion: Sestrin 2 is increased in patients with severe asthma as part of a mechanism that may modify structural alterations through the imbalance between oxidative stress and antioxidant activity.

Characteristics and treatment regimens across ERS SHARP severe asthma registries

Little is known about the characteristics and treatments of patients with severe asthma across Europe, but both are likely to vary. This is the first study in the European Respiratory Society Severe Heterogeneous Asthma Research collaboration, Patient-centred (SHARP) Clinical Research Collaboration and it is designed to explore these variations. Therefore, we aimed to compare characteristics of patients in European severe asthma registries and treatments before starting biologicals.This was a cross-sectional retrospective analysis of aggregated data from 11 national severe asthma registries that joined SHARP with established patient databases.Analysis of data from 3236 patients showed many differences in characteristics and lifestyle factors. Current smokers ranged from 0% (Poland and Sweden) to 9.5% (Belgium), mean body mass index ranged from 26.2 (Italy) to 30.6 kg·m^-2 (the UK) and the largest difference in mean pre-bronchodilator forced expiratory volume in 1 s % predicted was 20.9% (the Netherlands versus Hungary). Before starting biologicals patients were treated differently between countries: mean inhaled corticosteroid dose ranged from 700 to 1335 µg·day^-1 between those from Slovenia versus Poland when starting anti-interleukin (IL)-5 antibody and from 772 to 1344 µg·day^-1 in those starting anti-IgE (Slovenia versus Spain). Maintenance oral corticosteroid use ranged from 21.0% (Belgium) to 63.0% (Sweden) and from 9.1% (Denmark) to 56.1% (the UK) in patients starting anti-IL-5 and anti-IgE, respectively.The severe asthmatic population in Europe is heterogeneous and differs in both clinical characteristics and treatment, often appearing not to comply with the current European Respiratory Society/American Thoracic Society guidelines definition of severe asthma. Treatment regimens before starting biologicals were different from inclusion criteria in clinical trials and varied between countries.

Real-life studies of biologics used in asthma patients: key differences and similarities to trials

Introduction: The precision medicine approach that is now mandatory for severe asthma management includes the use of novel biologic agents blocking specific immunological mechanisms that are responsible for disease phenotypes and endotypes: monoclonal antibodies blocking IgE, IL-5 and IL-4/IL-13 immunological pathways are so far available. Areas covered: Clinical trials involving a large number of patients proved their efficacy in reducing asthma exacerbations, improving lung function and quality of life, and reducing the need for systemic corticosteroid treatment. Since biologics have been available for routine use, a series of real-life experiences on severe asthmatics treated with them have been published: these studies confirmed the beneficial effects in a real-world setting (effectiveness) of these drugs and showed novel aspects that were not covered by clinical trials, such as their effect on particular subgroup of patients, unexpected adverse events, and potential novel indications. Expert opinion: Both clinical trials and real-life experiences are needed to establish robust data on biologic agents for severe asthma, with real-life studies giving more broader insights on different aspects related to the biologics themselves and to the disease.

Th2/Th17 cytokine profile in phenotyped Greek asthmatics and relationship to biomarkers of inflammation

OBJECTIVE

The aim of the present study was to investigate the Th2/Th17 pathway in asthmatic patients and also the relationship to asthma severity and biomarkers of inflammation.

METHODS

90 asthmatic patients, 51 patients with severe, 39 patients with mild asthma and 98 healthy controls were included. Skin prick tests, blood eosinophils, total serum IgE and exhaled FeNO were evaluated. Serum levels of IL-4, IL-5, IL-13, IL-6, IL-17A, IL-23 and TGFβ1 were determined by Flow Cytometry using a panel kit (AimPlex Biosciences). The SNP of IL17A (rs17880588) was genotyped using reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

The genotype of the SNP in IL17A (rs 17880588) was similar among all three groups. Serum levels of IL-4, IL-5, IL-13, IL-6, IL-17A and IL-23 were higher in asthmatics compared to controls (p < 0.05). In addition, IL-17A and IL-4 serum levels were found significantly elevated in patients with allergic asthma (p < 0.05). Furthermore, IL-4, IL-5, IL-13 and IL-23 were found significantly higher in patients with eosinophil cut off values above 300 cells/μl (p < 0.05). IL-17A levels were positively correlated with FeNO values in severe asthmatics with eosinophils>400 cells/μl.

CONCLUSIONS

The above findings suggest the coexistence of Th2/Th17 pathway in severe, eosinophilic and in allergic asthma.