Improvement trend for individual health guidance intervention according to Japan clinical guidelines by public health nurses for type 2 diabetes mellitus who visited for medical checkups regularly: a case-control preliminary report.

We conducted a retrospective case-control study to assess the efficacy of personalized health guidance interventions on individuals with type 2 diabetes mellitus and obesity. A selection was made of individuals in regular visits to the Takagi Hospital for medical checkups between January 2017, and October 2021. Totally, 108 subjects (cases) with health guidance were divided into 2 groups: one group without pharmacotherapy for diabetes mellitus in medical institutions (n = 92) and another group with pharmacotherapy (n = 116). Cases were provided with personalized health guidance interventions by public health nurses for 30 min, in accordance with the Japanese clinical guidelines for the prevention of lifestyle-related diseases. Sex- and age-matched controls were chosen from individuals with diabetes mellitus without health guidance. The intervention without pharmacotherapy resulted in improvements in health indicators, including body weight, waist circumference, diastolic blood pressure, triglyceride levels, and γ-glutamyl trans-peptidase. These positive effects were not observed in the control group without health guidance. The therapeutic effects of health guidance were observed in cases where pharmacotherapy was administered. In conclusion, the implementation of individual health guidance interventions may prove to be effective for individuals with type 2 diabetes mellitus and obesity who regularly attend medical checkups.

A novel assay for improved detection of sputum periostin in patients with asthma.

BACKGROUND: Serum periostin associates with type-2 inflammation in asthmatic airways, but also reflects whole body periostin levels originating from multiple sources. Less is known about sputum periostin as a biomarker in asthma as detection levels are low using currently available periostin assays. We aimed to investigate detection of sputum periostin using ELISA assays targeting different periostin epitopes and relate levels to clinical characteristics. METHODS: Two ELISA systems were developed using antibodies detecting whole periostin or cleavage products, the molecular weight and amino acid sequences of which were confirmed. The ELISA assays were applied to sputum from 80 patients with mild-to-moderate and severe asthma enrolled in the European, multi-center study BIOAIR. Results were related to clinical characteristics. RESULTS: Sputum was found to contain smaller periostin fragments, possibly due to proteolytic cleavage at a C-terminal site. Comparing ELISA methodology using antibodies against cleaved versus whole periostin revealed detectable levels in 90% versus 44% of sputum samples respectively. Sputum periostin showed associations with blood and sputum eosinophils. Furthermore, sputum, but not serum, periostin correlated with reduced lung function and sputum IL-13 and was reduced by oral corticosteroid treatment. CONCLUSIONS: We present an ELISA method for improved analysis of sputum periostin by detecting cleavage products of the periostin protein. Using this assay, sputum periostin was detectable and associated with more disease-relevant parameters in asthma than serum periostin. Sputum periostin is worth considering as a phenotype-specific biomarker in asthma as its proximity to the airways may eliminate some of the confounding factors known to affect serum periostin.

Establishment of a novel ELISA system for measuring periostin independently of formation of the IgA complex.

BACKGROUND: Periostin, a matricellular protein that modulates cell functions having various pathophysiological roles, has the potential to be a useful biomarker for various diseases. We recently found that periostin forms a complex with IgA in human serum, which may affect the periostin measurement. METHODS: We investigated (1) whether the formation of the periostin-IgA complex affects the original periostin ELISA system, decreasing the values of serum periostin? (2) bow each domain of periostin affects periostin measurement by the original periostin ELISA system? (3) whether we can establish a novel ELISA system that is not affected by formation of the IgA complex? RESULTS: The periostin value at the reducing condition was significantly higher than that of the non-reducing condition, demonstrating that formation of the IgA complex affects periostin measurement. The monoclonal antibodies (mAbs) for periostin recognizing the EMI and R1 domains immunoprecipitated serum periostin in the reducing condition more than in the non-reducing condition, whereas the mAbs recognizing the R2 or R3 domain immunoprecipitated comparable amounts of serum periostin in the reducing and non-reducing conditions, suggesting the EMI and R1 domains contribute to formation of the complex with IgA. Using SS16A recognizing the R3 domain combined with SS17B recognizing the R4 domain, we established an ELISA system that was able to measure periostin independently of the IgA complex. CONCLUSIONS: We have established a novel ELISA system that measures periostin independently of the IgA complex. This system is promising in identifying periostin as a biomarker for various diseases.

Squamous cell carcinoma antigens are sensitive biomarkers for atopic dermatitis in children and adolescents: a cross-sectional study.

BACKGROUND: We recently reported that squamous cell carcinoma antigen 2 (SCCA2) is a reliable biomarker for atopic dermatitis (AD). OBJECTIVE: To further clarify its utility, we investigated for effects of comorbid allergies and AD treatment on serum SCCA levels. METHODS: Volunteers <18 years old were recruited through our website. Their allergic status was elucidated using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. We also recruited pediatric patients who were hospitalized because of severe AD. The serum levels of SCCA1 and SCCA2 were measured by enzyme-linked immunosorbent assays. In the severe AD patients, the levels of thymus and activation-regulated chemokine (TARC), SCCA1, and SCCA2 were measured before and after hospitalization. The severity of AD was assessed using the severity scoring of atopic dermatitis (SCORAD). RESULTS: A total of 576 participants (547 volunteers and 29 patients) were enrolled in the study. The levels of SCCA1 and SCCA2 were significantly higher in volunteers with mild AD and patients with severe AD than in healthy volunteers without allergic diseases. The levels were not elevated in those who had mild bronchial asthma or allergic rhinitis without AD. TARC, SCCA1, and SCCA2 were decreased during the treatment in severe AD patients, reflecting clinical improvement in response to treatment. Linear regression analysis for predicting a decrease in the SCORAD index showed R2 values of 0.16, 0.38, and 0.48 for TARC, SCCA1, and SCCA2, respectively. CONCLUSION: SCCAs, especially SCCA2, are sensitive biomarkers for detecting AD in children and adolescents and for assessing the severity and response to treatment of severe AD.

T1 invasive lung adenocarcinoma: Thin-section CT solid score and histological periostin expression predict tumor recurrence.

Adenocarcinoma is the most common histological type of non-small cell lung cancer (NSCLC), and various biomarkers for predicting its prognosis after surgical resection have been suggested, particularly in early-stage lung adenocarcinoma. Periostin (also referred to as POSTN, PN or osteoblast-specific factor) is an extracellular matrix protein, the expression of which is associated with tumor invasiveness in patients with NSCLC. In the present study, the novel approach, in which the thin-section CT findings prior to surgical resection and periostin expression of resected specimens were analyzed in combination, was undertaken to assess whether the findings could be a biomarker for predicting the outcomes following resection of T1 invasive lung adenocarcinoma. A total of 73 patients who underwent surgical resection between January 2000 and December 2009 were enrolled. A total of seven parameters were assessed in the thin-section CT scans: i) Contour; ii) part-solid ground-glass nodule or solid nodule; iii) percentage of solid component (the CT solid score); iv) presence of air-bronchogram and/or bubble-like lucencies; v) number of involved vessels; vi) shape linear strands between the nodule and the visceral pleura; and vii) number of linear strands between the nodule and the visceral pleura. Two chest radiologists independently assessed the parameters. Periostin expression was evaluated on the basis of the strength and extent of staining. Univariate and multivariate analyses were subsequently performed using the Cox proportional hazards model. There was a substantial to almost perfect agreement between the two observers with regard to classification of the seven thin-section CT parameters (κ=0.64-0.85). In the univariate analysis, a CT solid score >80%, pathological lymphatic invasion, tumor and lymph node status and high periostin expression were significantly associated with recurrence (all P<0.05). Multivariate analysis demonstrated that a CT solid score >80% and high periostin expression were risk factors for recurrence (P=0.002 and P=0.011, respectively). The cumulative recurrence rates among the three groups (both negative, CT solid score >80% or high periostin expression, or both positive) were significantly different (log-rank test, P<0.001). Although the solid component is already known to be a major predictor of outcome in lung adenocarcinomas according to previous studies, the combined analysis of CT solid score and periostin expression might predict the likelihood of tumor recurrence more precisely.

High serum free IL-18 is associated with decreased omalizumab efficacy: findings from a 2-year omalizumab treatment study.

OBJECTIVE: Omalizumab is more effective in severe allergic patients with eosinophilic asthma than those with non-eosinophilic asthma. IL-18, a unique cytokine involved in allergic but non-eosinophilic inflammation, might be associated with the latter condition. We aimed to clarify the roles of IL-18 related pathways in insufficient response to omalizumab treatment. METHODS: Patients with severe allergic asthma who completed 2-year omalizumab treatments at Kyoto University Hospital were included in this study (UMIN000002389). Associations between pretreatment levels of serum free IL-18 in addition to other mediators and asthma phenotypes including responses to omalizumab treatment were analyzed. Changes in serum free IL-18, periostin and total IgE levels during the treatment were also examined. RESULTS: Twenty-seven patients (19 females, average age of 55.7 years) were examined. Fifteen incomplete responders who experienced exacerbations in the second year, were significantly and more frequently obese and showed significantly earlier asthma onset, lower blood eosinophils and more exacerbations before omalizumab treatment than complete responders. Significantly more patients showed high baseline serum free IL-18 levels (≥141 pg/mL, a threshold for the highest tertile) among the incomplete responders than complete responders. Patients with high serum free IL-18 levels shared similar characteristics with incomplete responders, showing significant reductions in serum total IgE levels during omalizumab treatment. Finally, serum free IL-18 levels negatively correlated with serum periostin levels at baseline and in change ratios. CONCLUSIONS: High baseline serum free IL-18 levels may predict reduced omalizumab efficacy in severe allergic patients with type-2 low asthma, regarding reduction of exacerbations.

Febuxostat Attenuates the Induction of Vascular Cell Adhesion Protein 1 by TNF-α in Human Umbilical Vein Endothelial Cells.

In a randomized trial, higher all-cause and cardiovascular mortality was observed in treatment with febuxostat than with allopurinol in patients with coexisting gout and serious cardiovascular conditions. In this study, we focus on an intervention of febuxostat or allopurinol as an anti-inflammatory treatment to reduce the transcription of nuclear factor-kappa B (NF-κB) and production of relevant inflammatory factors. We evaluated the effect of febuxostat on vascular cell adhesion protein 1 (VCAM-1) induction in cultured human umbilical vein endothelial cells (HUVECs). Cells were exposed to tumor necrosis factor (TNF)-α (10 ng/mL) treatment for 24 h. Febuxostat or allopurinol (0.1-100 µM) was added to the bath medium 15 min before TNF-α treatment. VCAM-1 levels in HUVECs increased after 24-h TNF-α treatment (n = 4). Febuxostat and allopurinol significantly suppressed VCAM-1 induced by treatment with TNF-α in a dose-dependent manner (p < 0.05, n = 4). Furthermore, these drugs suppressed the NF-κB protein levels in the nucleus 4 h after TNF-α treatment (n = 3 or 4). Our results suggest that TNF-α induces VCAM-1 production via NF-κB, which can be blocked by febuxostat or allopurinol. The effect of febuxostat treatment on cardiovascular events may be associated with protection against the infiltration of lymphocytes or monocytes through VCAM-1 induction in inflamed endothelial cells such as arterial sclerosis.

Role of serum periostin in severe obstructive sleep apnea with albuminuria: an observational study.

BACKGROUND: Periostin is a matricellular protein and is a useful marker in respiratory diseases. However, the roles of periostin in patients with obstructive sleep apnea (OSA) remain unclear. Several in vitro studies have suggested that mechanical stress, hypoxia, impaired metabolism, and kidney injury, which often accompany OSA, may upregulate the expression of periostin. Meanwhile, serum periostin level has been negatively associated with body mass index (BMI) in the general population. In this study, we hypothesized that a high level of serum periostin despite being overweight/obese may discriminate severe OSA or OSA with comorbidities from mild OSA with obesity alone. We aimed to clarify the roles of periostin in patients with OSA to assist in elucidating the heterogeneity of OSA with comorbidities. METHODS: Among patients diagnosed as OSA, we examined the associations between serum periostin levels and clinical indices, including the severity of OSA, BMI, and comorbidities, using a multifaceted approach. The serum periostin levels and clinical indices were assessed after 3 months of continuous positive airway pressure (CPAP) treatment. RESULTS: In 96 patients with OSA, serum periostin level was negatively correlated with BMI, albeit marginally, and tended to be higher in severe OSA than in others when adjusted for BMI. Cluster analysis identified four clusters, including two severe OSA clusters, one of which was characterized by high serum periostin levels and the presence of comorbidities, including albuminuria. In a comparative analysis of severe OSA cases (n = 53), the level of serum-free fatty acids and the frequency of albuminuria were higher in patients with high serum periostin level of ≥87 ng/mL, which was the highest quintile among all participants, than in those with low serum periostin levels (< 87 ng/mL, n = 41). In patients with severe OSA and high serum periostin levels, the levels of serum periostin and urinary albumin significantly decreased after 3 months of CPAP treatment. CONCLUSIONS: Elevated serum periostin in patients with OSA despite being overweight/obese may be an indicator of severe OSA with comorbidities, particularly albuminuria.

Periostin forms a functional complex with IgA in human serum.

BACKGROUND: Periostin is a matricellular protein belonging to the fasciclin family, playing a role for the pathogenesis of allergic diseases by binding to integrins on cell surfaces. Serum periostin is elevated in various allergic diseases reflecting type 2 inflammation and tissue remodeling so that for allergic diseases, periostin is expected to be a novel biomarker for diagnosis, assessing severity or prognosis, and predicting responsiveness to treatments. We have previously shown that most serum periostin exists in the oligomeric form by intermolecular disulfide bonds. METHODS: In this study, we examined how periostin forms a complex in serum, whether the periostin complex in serum is functional, and whether the complex formation interferes with reactivity to anti-periostin Abs. RESULTS: We found that periostin formed a complex with IgA1 at a 1:1 ratio. The periostin in the serum complex contained at least five different isoforms. However, IgA was not essential for the oligomeric formation of periostin in mouse serum or in IgA-lacking serum. The periostin-IgA complex in human serum was functional, sustaining the ability to bind to αVß3 integrin on cell surfaces. Moreover, periostin formed the complex with IgA broadly, which interferes the binding of the Abs recognizing all of the domains except the R4 domain to periostin. CONCLUSIONS: Periostin is a novel member of the IgA-associated molecules. These results are of great potential use to understand the pathological roles of periostin in allergic diseases and, from a practical standpoint, to develop diagnostics or therapeutic agents against periostin.

An agonistic anti-Toll-like receptor 4 monoclonal antibody as an effective adjuvant for cancer immunotherapy.

Immune-checkpoint blockade antibodies have been approved for the treatment of cancer. However, poorly immunogenic tumours are less responsive to such therapies. Agonistic anti-Toll-like receptor 4 (TLR4) monoclonal antibodies (mAbs) activate only cell-surface TLR4; in contrast, lipopolysaccharide (LPS) activates both TLR4 and intracellular inflammatory caspases. In this study, we investigated the adjuvant activity of an anti-TLR4 mAb in T-cell-mediated antitumour immunity. The anti-TLR4 mAb induced the activation of antigen-specific T-cells in adoptive transfer studies. The growth of ovalbumin (OVA)-expressing tumours was significantly suppressed by administration of OVA and the anti-TLR4 mAb in combination, but not individually. The antitumour effect of anti-PD-1 mAb was enhanced in mice administered with OVA plus the anti-TLR4 mAb. The OVA-specific IFN-γ-producing CD8 T-cells were induced by administration of OVA and the anti-TLR4 mAb. The suppression of tumour growth was diminished by depletion of CD8, but not CD4, T-cells. The inflammatory response to the anti-TLR4 mAb was of significantly lesser magnitude than that to LPS, as assessed by NF-κB activation and production of TNF-α, IL-6 and IL-1ß. Administration of LPS (at a dose that elicited levels of proinflammatory cytokines comparable to those by the anti-TLR4 mAb) plus OVA induced no or less-marked activation of OVA-specific T-cells and failed to suppress tumour growth in mice. In conclusion, the agonistic anti-TLR4 mAb induces potent CD8 T-cell-dependent antitumour immunity and an inflammatory response of lesser magnitude than does LPS. The agonistic anti-TLR4 mAb has potential as an adjuvant for use in vaccines against cancer.

Ability of Periostin as a New Biomarker of Idiopathic Pulmonary Fibrosis.

The primarily pathogenesis of IPF, an incurable respiratory disease is believed to over-repair to lung injury. The development of new drugs for IPF has increased the necessity of identifying biomarkers for predicting clinical behavior and the selection of the appropriate treatment strategy for individual patient.We and another group found that periostin, a matricellular protein expressed specifically in areas of ongoing fibrotic lesions, such as fibroblastic foci in lung tissues from human IPF or murine bleomycin-induced lung injury models. Murine bleomycin-induced lung injury was improved by the constant suppression of periostin expression and treatment with neutralizing anti-periostin antibodies at the fibroproliferative phase. Moreover, total periostin can predict both short-term declines of pulmonary function and overall survival in IPF patients. Our group also established a new enzyme-linked immunosorbent assay (ELISA) kit that is more specific for IPF compared with the conventional kit. This new periostin ELISA kit specifically detects monomeric form, whereas the conventional kit detects both monomeric and oligomeric forms. The monomeric periostin levels can be used to predict pulmonary function decline and to distinguish IPF patients from healthy controls.In conclusion, periostin may play an important role in fibrogenesis and could be a potential biomarker for predicting disease progression and therapeutic effect in IPF patients.

Pirfenidone Improves Familial Idiopathic Pulmonary Fibrosis without Affecting Serum Periostin Levels.

Background: Antifibrotic agents have been approved for the treatment of idiopathic pulmonary fibrosis (IPF). However, the efficacy of these drugs in the treatment of familial IPF (FIPF) has not been previously reported. Case presentation: We report the case of a 77-year-old man with FIPF, successfully treated with pirfenidone. His uncle died due to IPF, and his niece was diagnosed with the disease. He had worsening dyspnea two months prior to admission to our hospital. Upon admission, he had desaturation when exercising and broad interstitial pneumonia. Administration of pirfenidone improved his dyspnea, desaturation, and the reticular shadow on his chest radiograph. Increased fibrotic marker levels KL-6 and SP-D were also normalized in six months; treatment had no effect on his serum periostin level. Pirfenidone has been effective for over two years. Conclusion: Antifibrotic agents such as pirfenidone may be useful for the management of FIPF, as well as cases of sporadic IPF.

Periostin as a predictor of prognosis in chronic bird-related hypersensitivity pneumonitis.

BACKGROUND: Periostin is an established biomarker of Th2 immune response and fibrogenesis. Recent research has indicated that periostin plays an important role in the pathogenesis of idiopathic interstitial pneumonias. To clarify the relationship between periostin and pathogenesis in chronic bird-related hypersensitivity pneumonitis (HP) and to reveal the usefulness of serum periostin levels in diagnosing and managing chronic bird-related HP. METHODS: We measured serum periostin in 63 patients with chronic bird-related HP, 13 patients with idiopathic pulmonary fibrosis, and 113 healthy volunteers. We investigated the relationship between serum periostin and clinical parameters, and evaluated if the baseline serum periostin could predict the prognosis. RESULTS: Serum periostin was significantly higher in patients with chronic bird-related HP compared to the healthy volunteers. In chronic bird-related HP, serum periostin had significant positive correlations with serum KL-6 levels, the CD4/CD8 ratio in bronchoalveolar lavage fluid, and fibrosis score on HRCT, and a significant negative correlation with the diffusing capacity of the lungs for carbon monoxide. Chronic bird-related HP patients with serum periostin levels exceeding ≥92.5 ng/mL and ≥89.5 ng/mL had a significantly worse prognosis and significantly higher frequency of acute exacerbation, respectively. Higher serum periostin (92.5 ng/mL or higher; binary response for serum periostin) was an independent prognostic factor in multivariate analysis. CONCLUSIONS: Serum periostin may reflect the extent of lung fibrosis and play an important role in pathogenesis of chronic bird-related HP. Elevated serum periostin could be a predictor of prognosis in patients with chronic bird-related HP.

Elevated Periostin Concentrations in the Bronchoalveolar Lavage Fluid of Patients with Eosinophilic Pneumonia.

BACKGROUND: Eosinophilic pneumonia (EP) is characterized by massive pulmonary infiltration by eosinophils. Although serum periostin is a novel marker for eosinophil-dominant asthma, the upregulation of periostin in the airway of asthmatics is controversial. In this study, we examined whether periostin concentrations are elevated in the bronchoalveolar lavage fluid (BALF) of patients with EP. METHODS: BAL was performed in healthy volunteers and in patients with acute eosinophilic pneumonia (AEP), chronic eosinophilic pneumonia (CEP), and sarcoidosis. The periostin concentrations in the BALF were measured. RESULTS: The periostin concentration in the BALF increased significantly with pulmonary eosinophil ia and was higher in AEP and CEP patients than in healthy volunteers and sarcoidosis patients, even after adjusting the albumin concentration. In pulmonary eosinophilia, the periostin concentration correlated with the eosinophil and lymphocyte counts, the concentration of albumin, and the concentration of cytokines such as IL-5, IL-13, and transforming growth factor ß1. CONCLUSIONS: Although some blood leakage may be involved in the elevation of periostin in the BALF of EP, periostin can be induced locally, at least in part. Therefore, periostin may play a role in the development of EP.

Impaired antigen-specific lymphocyte priming in mice after Toll-like receptor 4 activation via induction of monocytic myeloid-derived suppressor cells.

In sepsis, the pathology involves a shift from a proinflammatory state toward an immunosuppressive phase. We previously showed that an agonistic anti-TLR4 antibody induced long-term endotoxin tolerance and suppressed antigen-specific secondary IgG production when primed prior to immunization with antigen. These findings led us to speculate that TLR4-induced innate tolerance due to primary infection causes an immunosuppressive pathology in sepsis. Therefore, the mechanism underlying impaired antigen-specific humoral immunity by the TLR4 antibody was investigated. We showed, in a mouse model, that primary antigen-specific IgG responses were impaired in TLR4 antibody-induced tolerized mice, which was the result of reduced numbers of antigen-specific GC B cells and plasma cells. Ovalbumin-specific CD4 and CD8 T-cell responses were impaired in TLR4 antibody-injected OT-I and -II transgenic mice ex vivo. Adoptive transfer studies demonstrated suppression of OVA-specific CD4 and CD8 T-cell responses by the TLR4 antibody in vivo. The TLR4 antibody induced Gr1+ CD11b+ myeloid-derived suppressor cell (MDSC) expansion with suppression of T-cell activation. Monocytic MDSCs were more suppressive and exhibited higher expression of PD-L1 and inducible nitric oxidase compared with granulocytic MDSCs. In conclusion, immune tolerance conferred by TLR4 activation induces the expansion of monocytic MDSCs, which impairs antigen-specific T-cell priming and IgG production.

Serum periostin levels serve as a biomarker for both eosinophilic airway inflammation and fixed airflow limitation in well-controlled asthmatics.

OBJECTIVE: Periostin, a matricellular protein, is produced from airway epithelial cells and lung fibroblasts by IL-13. It has been suggested that periostin is involved in allergic inflammation and fibrosis. However, the usefulness of serum periostin measurement in the assessment of airway inflammation and remodeling and management of asthmatic patients is still debated. We aimed to determine whether serum periostin levels reflect eosinophilic airway inflammation and airway remodeling in asthma. METHODS: We examined the relationship of serum periostin levels with clinical features, biomarkers for eosinophilic airway inflammation, fraction of exhaled nitric oxide (FeNO) levels and blood eosinophil counts, and pulmonary functions in 235 well-controlled asthmatic patients on inhaled corticosteroids (ICS) treatment. RESULTS: Serum periostin levels were positively correlated with blood eosinophil counts (%) and age (r = 0.36 and 0.23, respectively), and were negatively correlated with body weight and FEV1/FVC (%) (r = -0.24 and - 0.23, respectively) in well-controlled asthmatic patients on ICS treatment (daily dose of 453 µg equivalent to fluticasone propionate). Blood eosinophil counts and serum periostin levels were similarly associated with increased FeNO levels (≥40 ppb) in the asthmatics. Serum periostin levels were better associated with fixed airflow limitation (FEV1/FVC ratio <70%) than FeNO levels, blood eosinophil counts or total IgE levels in the asthmatics. Multivariate analysis showed that fixed airflow limitation was significantly associated with high serum periostin levels (≥97 ng/ml) (Odds ratio 3.2). CONCLUSIONS: Serum periostin levels serve as a biomarker for both eosinophilic airway inflammation and fixed airflow limitation in well-controlled asthmatics on ICS treatment.

Fixed airflow obstruction relates to eosinophil activation in asthmatics.

BACKGROUND: Some asthmatics develop irreversible chronic airflow obstruction, for example, fixed airflow obstruction (fixed-AO). This is probably a consequence of airway remodelling, but neither its relation to inflammation nor which asthma biomarkers can be clinically useful are elucidated. We hypothesized that the presence of type 2 inflammation relates to fixed-AO. OBJECTIVES: To evaluate the presence of four markers for type 2 inflammation in fixed airflow obstruction among asthmatics. METHODS: This was a cross-sectional study of 403 participants with asthma, aged 17-75 years, from three Swedish centres. Fixed airflow obstruction was defined as forced expiratory volume during the first second (FEV1 ) over forced vital capacity (FVC) being below the lower limit of normal (LLN). The following type 2 inflammation markers were assessed: exhaled nitric oxide (FeNO), serum periostin, serum eosinophil cationic protein (S-ECP), and urinary eosinophil-derived neurotoxin (U-EDN). RESULTS: Elevated U-EDN (values in the highest tertile, ≥65.95 mg/mol creatinine) was more common in subjects with fixed-AO vs. subjects without fixed-AO: 55% vs. 29%, P < 0.001. Elevated U-EDN related to increased likelihood of having fixed-AO in both all subjects and never-smoking subjects, with adjusted (adjusted for sex, age group, use of inhaled corticosteroids last week, atopy, early-onset asthma, smoking history, and packyears) odds ratios (aOR) of 2.38 (1.28-4.41) and 2.51 (1.04-6.07), respectively. In a separate analysis, having both elevated S-ECP (>20 µg/L) and U-EDN was related to having the highest likelihood of fixed-AO (aOR (95% CI) 6.06 (2.32-15.75)). Elevated serum periostin or FeNO did not relate to fixed-AO. CONCLUSIONS AND CLINICAL RELEVANCE: These findings support that type 2 inflammation, and in particular eosinophil inflammation, is found in asthma with fixed-AO. This could indicate a benefit from eosinophil-directed therapies. Further longitudinal studies are warranted to investigate causality and relation to lung function decline.