FEV1 decline in relation to blood eosinophils and neutrophils in a population-based asthma cohort

Increased blood eosinophils and airflow obstruction as new-onset asthma predictors in the elderly: The Nagahama study

BACKGROUND

Asthma in the elderly needs more attention in an aging society. However, it is likely to remain underdiagnosed and undertreated. This study aimed to clarify clinical characteristics of new-onset asthma in the elderly, describing the prevalence, predictive factors, and comorbidities after asthma diagnosis of new-onset asthma in the elderly in the general population.

METHODS

This community-based prospective cohort study enrolled 9804 generally healthy participants (30-74 years old) in Nagahama City, and conducted a follow-up assessment after 5 years. Elderly participants were those aged ≥65 years at baseline. Patients with new-onset asthma were defined as participants without asthma at baseline assessment and with asthma at the follow-up assessment.

RESULTS

Among the 7948 participants analyzed in this study, 28 (1.4%) elderly and 130 (2.2%) non-elderly had new-onset asthma. Multiple logistic regression analysis revealed low forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and high blood eosinophil counts at baseline as predicting factors for new-onset asthma in the elderly. Additionally, subsequent incidence of new-onset asthma was higher in elderly participants with both predictors (high blood eosinophil counts and low FEV1/FVC at baseline) than those with none or one of the predictors before asthma diagnosis. Lastly, elderly patients with new-onset asthma had more frequent comorbidity of moderate to severe sleep disordered breathing than those non-elderly.

CONCLUSIONS

Eosinophilic inflammation and airflow obstruction may predict subsequent new-onset asthma after the age of 65 years. Revealing the characteristics of new-onset asthma in the elderly can aid in the prevention of underdiagnosed asthma.

Age-related differences in associations between uncontrolled asthma, comorbidities and biomarkers in adult-onset asthma

OBJECTIVE

Adult-onset asthma is a recognized but heterogeneous phenotype and has been described to associate with poor asthma control. Knowledge about associations between clinical characteristics including comorbidities and control of adult-onset asthma is limited, especially in older populations. We aimed to study how clinical biomarkers and comorbidities are associated with uncontrolled asthma among middle-aged and older individuals with adult-onset asthma.

METHODS

Clinical examinations including structured interview, asthma control test (ACT), spirometry, skin prick test (SPT), blood sampling, and measurement of exhaled fractional nitric oxide (FeNO) was performed in a population-based adult-onset asthma cohort in 2019-2020 (n = 227, 66.5% female). Analyses were performed among all included, and separately in middle-aged (37-64 years, n = 120) and older (≥65 years, n = 107) participants.

RESULTS

In bivariate analysis, uncontrolled asthma (ACT ≤ 19) was significantly associated with a blood neutrophil count ≥5/µl, BMI ≥30, and several comorbidities. In multivariable regression analysis, uncontrolled asthma was associated with neutrophils ≥5/µl (OR 2.35; 95% CI 1.11-4.99). In age-stratified analysis, BMI ≥30 (OR 3.04; 1.24-7.50), eosinophils ≥0.3/µl (OR 3.17; 1.20-8.37), neutrophils ≥5/µl (OR 4.39; 1.53-12.62) and allergic rhinitis (OR 5.10; 1.59-16.30) were associated with uncontrolled asthma among the middle-aged. Among the older adults, uncontrolled asthma was only associated with comorbidities: chronic rhinitis (OR 4.08; 1.62-10.31), ischemic heart disease (OR 3.59; 1.17-10.98), malignancy (OR 3.10; 1.10-8.73), and depression/anxiety (OR 16.31; 1.82-146.05).

CONCLUSIONS

In adult-onset asthma, comorbidities were strongly associated with uncontrolled asthma among older adults, while clinical biomarkers including eosinophils and neutrophils in blood were associated with uncontrolled asthma among middle-aged.

Deterioration of lung function and its association with eosinophil count

Exposure to lethal dust particles has a negative impact on human's health. This work investigated the association between respiratory symptoms and eosinophil levels between quarry workers and the controls. A total of 75 workers exposed to quarry dust and 45 age, sex, body mass index-matched unexposed controls participated in this study. Results of this study indicated that the quarry dust particles produced inflammatory responses, increasing the mean eosinophil level (7.56 ± 2.94), causing allergic respiratory symptoms such as rhinitis , chest tightness, wheeze, sputum production thus impairing the lung function with decline in FEV1(80.84 ±108.8) level in workers exposed to quarry dust compared to controls (P≤0.00**) Conclusion: The presence of increased levels of respiratory irritants in quarry sites may explain the higher prevalence of respiratory infections and exacerbated inflammatory reactions found to ascertain the link between increased eosinophil count and the lung impairment in quarry workers.

Association Between Blood Eosinophils and Neutrophils With Clinical Features in Adult-Onset Asthma

BACKGROUND

Asthma is a disease that can be separated into different phenotypes and endotypes based on the clinical characteristics and the molecular mechanisms of the condition, respectively.

OBJECTIVE

To assess the association between blood eosinophil and neutrophil counts with clinical and molecular features in patients with adult-onset asthma.

METHODS

Blood eosinophil and neutrophil counts were measured from 203 patients who took part in the Seinäjoki Adult Asthma Study and attended the 12-year follow-up visit. The patients were then divided into four groups (paucigranulocytic [n = 108], neutrophilic [n = 60], eosinophilic [n = 21], and mixed granulocytic [n = 14]), according to eosinophil and neutrophil levels. The cutoff values used to define the groups were 0.30 × 10⁹ · L^-1 for blood eosinophils and 4.4 × 10⁹ · L^-1 for blood neutrophils.

RESULTS

The neutrophilic group had highest body mass index. It was dispensed the highest doses of inhaled corticosteroids during the 12-year follow-up and made the most unplanned respiratory visits. The neutrophilic, eosinophilic, and mixed granulocytic groups had more severe asthma compared with the paucigranulocytic group. The neutrophilic and eosinophilic groups were associated with higher dispensed antibiotics. The eosinophilic group had more nasal polyps, more suspected sinusitis, a greater decline in lung function, and increased levels of periostin, FeNO, and IgE. The neutrophilic group had increased high-sensitivity C-reactive protein, matrix metalloproteinase-9, IL-6, leptin, and soluble urokinase plasminogen activator receptor levels. The mixed granulocytic group showed increased resistin levels together with the neutrophilic group.

CONCLUSIONS

In addition to blood eosinophils, the blood neutrophil count reflects underlying inflammatory patterns and indicates important differences in asthma clinical features and outcomes.

Measurement of Blood Eosinophils in Asthma and Chronic Obstructive Pulmonary Disease

Eosinophils are important effector cells in airway inflammation, as pleiotropy and heterogeneity can be linked to various pathophysiologies in asthma and chronic obstructive pulmonary disease (COPD). Sputum eosinophils can reflect the heterogeneity of airway inflammation, and owing to their traits, blood eosinophils can be a surrogate and potential biomarker for managing both conditions. Blood eosinophils are activated via the stimulation of type 2 cytokines, such as interleukin (IL)-5, IL-4/13, granulocyte-macrophage colony-stimulating factor, IL-33, and thymic stromal lymphopoietin. There is sufficient evidence to support the relationship between the blood eosinophil count and clinical outcomes, including pulmonary function decline, exacerbations, all-cause mortality, and treatment response to inhaled corticosteroids and biologics. Thus, there is growing interest in the use of blood eosinophils for the management of these diseases. Compiling recent evidence, we herein review the significance of measuring blood eosinophils in asthma and COPD.

Clinical Features and Efficacy of Benralizumab in Patients with Blood Eosinophil Count Between 300 and 450 Cells/mm3: A Post Hoc Analysis from the ANANKE Study

PURPOSE

Benralizumab effectively reduces severe eosinophilic asthma (SEA) exacerbations in patients with a wide range of baseline blood eosinophil count (BEC). Patients included in real-world studies are often characterized by high mean/median BEC, while patients with BEC close to 300 cells/mm3 are poorly represented. This post hoc analysis from the Italian study ANANKE aims to define the clinical features and corroborate the efficacy of benralizumab in real world in the BEC 300-450 cells/mm3 subset of patients.

PATIENTS AND METHODS

Post hoc analysis of the Italian, multicenter, observational, retrospective real-life study ANANKE (NCT04272463). Baseline clinical and laboratory characteristics were collected in the 12 months prior to benralizumab treatment and presented for a BEC 300-450 cells/mm3 subgroup of patients. Change over time of BEC, annualized exacerbation rate (AER), asthma control (ACT), lung function and oral corticosteroid (OCS) use at 16, 24 and 48 weeks after benralizumab introduction were collected.

RESULTS

A total of 164 patients were analyzed, 34 of whom with a BEC of 300-450 cells/mm3. This subgroup was more likely to be female (64.7%), with lower rates of severe exacerbations at baseline when compared to the total population (0.69 vs 1.01). After 48 weeks of benralizumab treatment, the BEC 300-450 subset showed similar reductions in AER (-94.8% vs -92.2%) and OCS use (median dose reduction of 100% in both groups), as well as improvement in ACT score (median scores 22.5 vs 22) and lung function (pre-BD FEV1: +200 mL vs +300 mL) when compared to the total population. No discontinuations for safety reasons were registered.

CONCLUSION

At baseline, apart from lower severe exacerbation rate, the BEC 300-450 cells/mm3 subset of patients is comparable to the total population prescribed with benralizumab. In this real-life study, benralizumab is as effective in BEC 300-450 patients as in the total population.

Comparison between clinical trials and real-world evidence studies on biologics for severe asthma

In recent years, the more widespread availability of biological drugs with specific mechanisms of action has led to significant breakthroughs in the management of severe asthma. Over time, numerous randomised clinical trials have been conducted to evaluate the efficacy and safety of these biologics and define the eligibility criteria of patients suitable for various therapeutic options. These studies were conducted under controlled conditions not always applicable to real life. For this and other reasons, real-world evidence and pragmatic studies are required to provide useful information on the effectiveness of biological drugs and their safety, even in the long term. Because differences in outcomes have sometimes emerged between clinical trials and real-life studies, it is important to clarify the causes of these discrepancies and define the significance of the results of studies conducted in the course of daily clinical practice. Thus, a scientific debate is ongoing, and no consensus has been reached. The purpose of this narrative review is to analyse the differences between randomised trials and real-world evidence studies, focusing on their roles in guiding clinicians among different therapeutic options and understanding the reasons for the large discrepancies often found in the results obtained.

Further evidence for association of YKL-40 with severe asthma airway remodeling

BACKGROUND

The chitinase-like protein YKL-40 is associated with airflow limitation on spirometry and airway remodeling in patients with asthma. It remains unclear whether YKL-40 is associated with morphologic changes in the airways and parenchyma or with future progression of airflow limitation in severe asthma.

OBJECTIVE

To evaluate the association of circulating YKL-40 levels with morphologic changes in the airways and parenchyma and with longitudinal progression of airflow limitation.

METHODS

The patients were participants in the Hokkaido Severe Asthma Cohort Study (n = 127), including smokers. This study consisted of 2 parts. In analysis 1, we analyzed associations between circulating YKL-40 levels and several asthma-related indices, including computed tomography-derived indices of proximal wall area percentage, the complexity of the airways (airway fractal dimension), and the parenchyma (exponent D) cross-sectionally (n = 97). In analysis 2, we evaluated the impact of circulating YKL-40 levels on forced expiratory volume in 1 second (FEV₁) decline longitudinally for a 5-year follow-up (n = 103).

RESULTS

Circulating YKL-40 levels were significantly associated with proximal wall area percentage and airway fractal dimension (r = 0.25, P = .01; r = -0.22, P = .04, respectively), but not with exponent D. The mean annual change in FEV₁ was -33.7 (± 23.3) mL/y, and the circulating YKL-40 level was a significant independent factor associated with annual FEV₁ decline (β = -0.24, P = .02), even after controlling for exponent D (β = -0.26, P = .01).

CONCLUSION

These results provide further evidence for the association of YKL-40 with the pathogenesis of airway remodeling in severe asthma.

Neutrophils and Asthma

Although eosinophilic inflammation is characteristic of asthma pathogenesis, neutrophilic inflammation is also marked, and eosinophils and neutrophils can coexist in some cases. Based on the proportion of sputum cell differentiation, asthma is classified into eosinophilic asthma, neutrophilic asthma, neutrophilic and eosinophilic asthma, and paucigranulocytic asthma. Classification by bronchoalveolar lavage is also performed. Eosinophilic asthma accounts for most severe asthma cases, but neutrophilic asthma or a mixture of the two types can also present a severe phenotype. Biomarkers for the diagnosis of neutrophilic asthma include sputum neutrophils, blood neutrophils, chitinase-3-like protein, and hydrogen sulfide in sputum and serum. Thymic stromal lymphoprotein (TSLP)/T-helper 17 pathways, bacterial colonization/microbiome, neutrophil extracellular traps, and activation of nucleotide-binding oligomerization domain-like receptor family, pyrin domain-containing 3 pathways are involved in the pathophysiology of neutrophilic asthma and coexistence of obesity, gastroesophageal reflux disease, and habitual cigarette smoking have been associated with its pathogenesis. Thus, targeting neutrophilic asthma is important. Smoking cessation, neutrophil-targeting treatments, and biologics have been tested as treatments for severe asthma, but most clinical studies have not focused on neutrophilic asthma. Phosphodiesterase inhibitors, anti-TSLP antibodies, azithromycin, and anti-cholinergic agents are promising drugs for neutrophilic asthma. However, clinical research targeting neutrophilic inflammation is required to elucidate the optimal treatment.

House Dust Mite Subcutaneous Immunotherapy and Lung Function Trajectory in Children and Adolescents with Asthma

Background: Allergen-specific immunotherapy is currently the only disease-modifying treatment for allergic asthma, and it has been shown to improve control of asthma while reducing both drug use and asthma exacerbations. However, its effects on lung function—especially its long-term effects—remain controversial. We aimed to identify factors associated with a possible beneficial effect of allergen-specific immunotherapy on lung function in asthma by retrospectively evaluating the long-term changes in lung function in children with asthma who received house dust mite subcutaneous immunotherapy (HDM-SCIT). Methods: We enrolled children with asthma who had undergone HDM-SCIT for more than 1 year. Clinical information and lung function measurements were retrieved from the electronic chart system. To characterize the trajectory of lung function change, we performed linear regression analysis to evaluate the maximal expiratory flow at 50% of the forced vital capacity during two periods: before and during HDM-SCIT. Slopes from a least-squares regression line for the two periods, i.e., S1 before HDM-SCIT and S2 during HDM-SCIT, were compared. The subjects were then classified into two groups: an improving group (Group I) defined as S2 − S1 > 0, and a declining group (Group D) defined as S2 − S1 < 0. The clinical factors at the start of HDM-SCIT were compared between the two groups. Results: A total of 16 patients were analyzed. Eight patients were classified into each of Group I and Group D. The mean ages were 10.5 and 11.8 years, and the mean treatment periods were 4.1 and 3.9 years. Group I had a significantly lower blood eosinophil count and a significantly higher HDM-specific IgE level than Group D. Logistic regression showed a strong relationship between those two markers and the lung function trajectory. Conclusion: Control of the blood eosinophil count in highly HDM-sensitized patients may increase the beneficial effect of HDM-SCIT on lung function.

Blood inflammatory phenotypes were associated with distinct clinical expressions of asthma in adults from a large population-based cohort

Background

Asthma is an inflammatory heterogeneous disease. Asthma inflammatory phenotypes based on blood eosinophil and neutrophil counts have never been identified and characterized in population-based studies.

Methods

Adults with current asthma and available blood eosinophil and neutrophil counts from the French population-based CONSTANCES cohort were included. Current asthma was defined by reports of asthma attacks, symptoms or treatments in the last 12 months. Inflammatory phenotypes were based on low (L) and high (H) blood (B) eosinophil (E) (LBE/HBE: </⩾0·25 × 10⁹/L, respectively) and neutrophil (N) (LBN/HBN: </⩾5 × 10⁹/L, respectively) cut-offs. Associations between inflammatory phenotypes and the clinical expressions of asthma were studied using logistic models adjusted for age, sex, smoking status, body mass index, education level, French deprivation index and treatment. Other cut-offs were applied. Stratified analyses according to age or sex were performed.

Findings

Among 15,019 adults with asthma (56% women, 59%≥40 years), the LBE/LBN (reference), LBE/HBN, HBE/LBN and HBE/HBN phenotypes accounted for 57%, 6%, 33% and 4% respectively. The LBE/HBN phenotype was associated with being awaken by an attack of coughing, chronic bronchitis, and dyspnoea (adjusted(a)OR ranging from 1·21 to 1·42). The HBE/LBN and HBE/HBN phenotypes were associated with asthma attacks (aOR=1·31[1·20-1·42], 1·25[1·02-1·53]) and asthma symptom score (p for trend<0·0001, p for trend=0·001, respectively). The HBE/LBN phenotype was also associated with being awaken with chest tightness (aOR=1·30[1·20-1·40]). Results were unchanged whatever the cut-offs used. No statistically significant heterogeneity was observed according to age or sex.

Interpretation

Differences in the clinical expressions of asthma were found between the phenotypes, reproducible whatever the cut-offs used, and similar to those observed in case-control and clinical studies. Such phenotypes are of interest to improve asthma management and study its environmental risk factors.

Funding

The CONSTANCES cohort receives grants from ANR (ANR-11-INBS-0002), the Caisse nationale d'assurance maladie-CNAM and the Ministry of research. CONSTANCES also receives funding from MSD, AstraZeneca, Lundbeck and L'Oréal, managed by INSERM-Transfert. T.Tsiavia is supported by a PhD grant from the Fondation pour le Recherche Médicale (ECO202006011654).

Among respiratory symptoms, wheeze associates most strongly with impaired lung function in adults with asthma: a long-term prospective cohort study

BACKGROUND

Asthma is a common disease and a major public health concern. Respiratory symptoms are related to its prognosis, which in turn associates with lung function. Still this association on a long-term basis is not entirely understood.

AIM

To study the association of the type and number of respiratory symptoms with FEV1 and FEV1 decline in women and men with asthma.

METHOD

A population-based cohort of adults with asthma was examined at study entry between 1986 and 2001 and at follow-up between 2012 and 2014, and n=977 had valid measurements of FEV1 on both occasions. Data regarding respiratory symptoms at study entry (recurrent wheeze, dyspnoea, longstanding cough and productive cough) were analysed in relation to FEV1 and annual decline in FEV1, both unadjusted and adjusted for other potentially associated factors by linear regression.

RESULTS

For both sexes recurrent wheeze and dyspnoea were associated with lower FEV1 at study entry and follow-up, while productive cough was associated with lower FEV1 only at follow-up. No associations were found between the type of symptoms and annual decline in FEV1. In adjusted analyses, the association between recurrent wheeze and lower FEV1 both at study entry and follow-up remained significant among women. Also, the association between a higher number of symptoms with lower FEV1 both at study entry and follow-up were present for both sexes and remained after adjustment.

CONCLUSIONS

Particularly recurrent wheeze and a higher number of respiratory symptoms may predict lower lung function also in the long run among women and men with asthma.

Bronchodilator response and lung function decline: Associations with exhaled nitric oxide with regard to sex and smoking status

Background

Fractional exhaled nitric oxide (FeNO) is a marker of type-2 inflammation used both to support diagnosis of asthma and follow up asthma patients. The associations of FeNO with lung function decline and bronchodilator (BD) response have been studied only scarcely in large populations.

Objectives

To study the association between FeNO and a) retrospective lung function decline over 20 years, and b) lung function response to BD among asthmatic subjects compared with non-asthmatic subjects and with regards to current smoking and sex.

Methods

Longitudinal analyses of previous lung function decline and FeNO level at follow-up and cross-sectional analyses of BD response and FeNO levels in 4257 participants (651 asthmatics) from the European Community Respiratory Health Survey.

Results

Among asthmatic subjects, higher percentage declines of FEV₁ and FEV₁/FVC were associated with higher FeNO levels (p = 0.001 for both) at follow-up. These correlations were found mainly among non-smoking individuals (p = 0.001) and females (p = 0.001) in stratified analyses.

Percentage increase in FEV₁ after BD was positively associated with FeNO levels in non-asthmatic subjects. Further, after stratified for sex and smoking separately, a positive association was seen between FEV₁ and FeNO levels in non-smokers and women, regardless of asthma status.

Conclusions

We found a relationship between elevated FeNO and larger FEV₁ decline over 20 years among subjects with asthma who were non-smokers or women. The association between elevated FeNO levels and larger BD response was found in both non-asthmatic and asthmatic subjects, mainly in women and non-smoking subjects.

Persistence of both reversible airway obstruction and higher blood eosinophils may predict lung function decline in severe asthma

OBJECTIVE

This study analysed whether the persistence of both reversible airway obstruction (RAO) and elevated BE counts was associated to reduced asthma control and accelerated lung function decline in treated severe asthmatics.

METHODS

About 202 severe asthmatics were studied after 12-120 months of step-5 treatment associated to anti-IgE therapy. Following treatments, reversibility tests, after inhaling 400 mcg of Salbutamol, were performed. FEV₁  > 12% or ≤12% changes differentiated RAO+ from RAO- subjects. Blood eosinophil (BE) counts after treatment were considered.

RESULTS

Pre-/post-treatment bronchodilator FEV₁ % and ACT were lower (61% [50-71], 74.4% [62.5-83.7] and 20[18-22]), whereas BE were higher (380 cells/µl [170-590]) in RAO+ compared to RAO- subjects (77% [64-88], p = 0.0001, 81.8% [66.1-94.3], p = 0.0001, 21[18-23], p = 0.045 and 230 cells/µl [80-360], p = 0.003). A negative relationship between SABA-induced FEV₁ % changes and pre-bronchodilator FEV₁ % (β = -0.551%; p = 0.0001) and ACT (β = -0.059; p = 0.038) was found. Conversely, post-treatment BE levels were positively related (β = 145.565 cells/µl; p = 0.003) to FEV₁  > 12% increases. A rising trend of pre-/post-bronchodilator FEV₁ % in time was observed in RAO- subjects with BE < 300 cells/µl. Conversely, we highlighted significant declining tendencies of pre/post-bronchodilator FEV₁ % in RAO+ patients with BE > 300 cells/µl reaching lower values after more than 36 months of step-5 treatment (59.6% [39.9-72.1] vs 74[66.5-89.2] of RAO+ individuals with BE < 300 cells/µl [p = 0.026] and 81.6% [66.1-91.8] of RAO-subjects with BE > 300 cells/µl [p = 0.009]).

CONCLUSION

Persistent SABA-induced FEV₁  > 12%, especially when associated to BE > 300 cells/ml, may be a marker of accelerated lung function decline in severe asthmatics despite maximal step-5 treatment. The highest bronchodilation associated to the lowest BE levels should be the main goal of asthma treatment to prevent such decline.

microRNA-130b-3p Contained in MSC-Derived EVs Promotes Lung Cancer Progression by Regulating the FOXO3/NFE2L2/TXNRD1 Axis

This study aimed to explore the molecular mechanism by which mesenchymal stem cells (MSCs) mediate lung cancer progression. Extracellular vesicles (EVs) were isolated from transfected or untransfected MSCs, and were co-cultured with lung cancer cells with/without microRNA-130b-3p (miR-130b-3p) inhibitor, mimic, overexpression plasmids of FOXO3/NFE2L2, or shRNAs. CCK-8 assay, colony formation, transwell assay, and flow cytometry were carried out to determine the biological functioning of lung cancer cells. Furthermore, FOXO3, Keap1, NFE2L2, and TXNRD1 expression was determined by qRT-PCR and western blot analysis. A tumor xenograft mouse model was used to determine role of EVs-miR-130b-3p and its target FOXO3 in lung cancer progression in vivo. miR-130b-3p was highly expressed in lung cancer tissues and MSC-derived EVs. Moreover, the MSC-derived EVs transferred miR-130b-3p to lung cancer cells to promote cell proliferation, migration, and invasion while repress cell apoptosis. miR-130b-3p directly targeted FOXO3, and FOXO3 elevated Keap1 expression to downregulate NFE2L2, thus inhibiting TXNRD1. FOXO3 overexpression or silencing of NFE2L2 or TXNRD1 diminished lung cancer cell proliferation, invasion, and migration but enhanced apoptosis. EV-delivered miR-130b-3p or FOXO3 silencing promoted lung cancer progression in vivo. In summary, MSC-derived EVs with upregulated miR-130b-3p suppressed FOXO3 to block the NFE2L2/TXNRD1 pathway, thus playing an oncogenic role in lung cancer progression.

mRNA expression analysis of interleukins 17A and 17F in bronchial asthmatic patients from Northern Indian population

INTRODUCTION

Asthma being a chronic inflammatory disease concerning to the airways involves genetic and environmental factors. It is known to develop a clinical condition of airway hyper-responsiveness, which induces frequent symptoms in patients such as breathlessness, chest congestion, coughing, and wheezing, particularly during night hours or during early morning hours. The cytokine, Interleukin 17F (IL17F), is important in mediating allergic reactions in the body and regulating the pathophysiology and pathogenesis of asthmatic attacks, as well as airway inflammation, respectively. The Interleukin 17A (IL17A) is involved in increasing the biosynthesis of interleukins IL-6 and IL11. In contrast, IL17F enhances the expression of interleukin IL11 and tumor growth factor, TGF-β.

METHODOLOGY

Standard procedures were followed for collection and processing of blood samples from the subjects (controls and patients, 104 each), isolation of mRNA and to determine the quantities of IgE, and the interlukins (IL17A and IL17F) in the serum. The Real-time PCR and ELISA techniques were employed for synthesis of cDNA and determination of interleukins, respectively, using standard protocols. Early diagnosis of asthma is still a challenge to meet.

RESULTS

The statistical analysis of the data reflected a positive correlation between each of the interleukins (IL-17A and IL17F) and IgE (p = 0.001 and r = 0.41), (p = 0.004 and r = 0.077). The results indicated the upregulation of expression of IL17A and IL17F genes in the patients suffering from asthma.

CONCLUSIONS

This study has indicated that the blood levels of IL-17A and IL17F could be utilized as viable clinical markers for early diagnosis, timely treatment, and proper management of asthma.