OBJECTIVES:To verify the hypothesis that growth differentiation factor 11 (GDF11) attenuates myocardial ischemia/reperfusion (MI/R) injury and explore the underlying mechanism. METHODS:To simulate MI/R injury, H9C2 cells were incubated in an anaerobic chamber (95% N2+5% CO2) for 9 h followed by 3 h of reoxygenation in the presence of GDF11 (10 nmol/L). The cells exposed to hypoxia/reoxygenation (H/R) or sham exposure were treated with GDF11 alone or in combination with the iNOS inhibitor 1400W, the Trx1 nitration inhibitor EUK134, human recombinant Trx1 (hTrx1) or N-Trx1, and the changes in cell viability was determined by MTT assay and LDH release assay. Cardiomyocyte apoptosis was determined by TUNEL staining and caspase-3 activity assessment, and oxidative stress levels were evaluated by measuring superoxide production and DHE staining. Nitrative stress in the cells was assessed by measuring total NO content and nitrotyrosine content. The expression levels of iNOS, gp91phox, ASK1 and p-ASK1 were detected using Western blotting, Trx1 activity was determined using insulin disulfide reduction assay, and Trx1 nitration was analyzed by immunoprecipitation. RESULTS:In H9C2 cells with H/R exposure, 10 nmol/L GDF11 treatment significantly increased cell viability, decreased LDH release, inhibited caspase-3 activation and cell apoptosis, and reduced superoxide production, total NO content and nitrotyrosine production. GDF11 also significantly inhibited iNOS expression, reversed H/R-induced increase of Trx1 nitration and inhibition of Trx1 activity, and inhibited ASK1 phosphorylation. Treatment of the cells with 1400W decreased LDH release and caspase-3 activity, and diminished total NO production and nitrotyrosine production. EUK134 diminished LDH release and caspase-3 activation, upregulated Trx activity, and inhibited superoxide production in H9C2 cells. N-Trx1 abolished the protective effects of GDF11 against H/R injury in the cardiomyocytes. CONCLUSIONS:GDF11 protects cardiomyocytes against H/R injury partially by attenuating oxidative/nitrative stress and inhibiting Trx1 nitrative inactivation.

ACE2 and Ang–(1–7) have important roles in preventing acute lung injury. However, it is not clear whether upregulation of the ACE2/Ang–(1–7)/Mas axis prevents LPS–induced injury in pulmonary microvascular endothelial cells (PMVECs) by inhibiting the MAPKs/NF–κB pathways. Primary cultured rat PMVECs were transduced with lentiviral–borne Ace2 or shRNA– Ace2 and then treated or not with Mas receptor blocker (A779) before exposure to LPS. LPS stimulation resulted in the higher levels of AngII, Ang–(1–7), cytokine secretion and apoptosis rates and the lower ACE2/ACE ratio. Ace2 reversed the ACE2/ACE imbalance and increased Ang–(1–7) levels, thus reducing LPS–induced apoptosis and inflammation, while inhibition of Ace2 reversed all these effects. A779 abolished these protective effects of Ace2 . LPS treatment was associated with activation of the ERK, p38, JNK and NF–κB pathways, which were aggravated by A779. Pretreatment with A779 prevented the Ace2 –induced blockade of p38, JNK and NF–κB phosphorylation. However, only JNK inhibitor markedly reduced apoptosis and cytokine secretion in PMVECs with Ace2 deletion and A779 pretreatment. These results suggest that the ACE2/Ang–(1–7)/Mas axis has a crucial role in preventing LPS–induced apoptosis and inflammation of PMVECs, by inhibiting the JNK/NF–κB pathways.

BACKGROUND:We investigated the role of the complement system, particularly complement C5, in severe asthma defined from an analysis of sputum proteomics. Although there has been evidence of complement activation in asthma, its role in severe asthma remains unclear. METHOD:Sputum protein expression profiles were analyzed from healthy controls and severe asthma patients using data-dependent acquisition mass spectrometry. Weighted correlation network analysis (WGCNA) was used to define the unique modules that were highly correlated with clinical, physiologic, and inflammatory traits. Differential analysis was performed for the complement C5 pathway protein levels and eosinophilic protein expression as influenced by C5. Asthmatic mouse models were used to verify the effect of complement C5 administration and inhibition. RESULTS:The WGCNA "brown" module related to the complement system activation was positively correlated with eosinophilic inflammation. Specifically, C5 and downstream complement proteins were up-regulated in patients with high sputum eosinophil levels (≥ 3%) compared to low sputum eosinophils (< 3%). Patients with reduced C5 expression had less eosinophilic inflammation and better lung function. Using single-cell RNA sequencing and immunofluorescence staining led to identification of macrophages as the main source of C5. In vivo experiments confirmed that inhibiting C5 reduced inflammation in allergic mouse models, while direct stimulation with recombinant C5 in IL-5 transgenic mice increased eosinophilic inflammation. CONCLUSION:We demonstrate a direct role for complement C5 in exacerbating eosinophilic inflammation in severe asthma.

Perioperative glucose variability (GV) is one of the key factors of patient prognosis. This Prospective Cohort study aimed to evaluate the association between perioperative GV and early postoperative functional recovery in elderly patients undergoing surgery for lumbar degenerative diseases. Elderly patients who underwent lumbar spine surgery from October 2024 to April 2025 were included. The coefficient of variation (CV) of glucose was calculated as an indicator of GV. We categorized the CV into three groups based on tertiles. Regression models evaluated GV’s impact on ODI and JOA. Subgroup analyses validated findings. A total of 171 patients (mean age 72.09 years; 44.44% male) were included in this study. GV showed a significant negative correlation with 3-month postoperative JOA (r=-0.209, P < 0.01) and a significant positive correlation with ODI (r = 0.339, P < 0.01). Multivariate regression analysis further identified GV as an independent predictor of decreased JOA scores (P = 0.035) and increased ODI scores (P < 0.001) in the early postoperative period. Subgroup analyses confirmed the consistency of the associations between GV and postoperative ODI and JOA across various subgroups. GV is closely related to early postoperative functional recovery in elderly patients with lumbar degenerative disease. Monitoring GV may be a valuable approach to predict the early postoperative functional outcomes in this patient population, potentially guiding more personalized treatment strategies and postoperative management to improve their early postoperative functional status and quality of life.

BACKGROUND:Tezepelumab, a human monoclonal antibody that blocks thymic stromal lymphopoietin, reduced the annualized asthma exacerbation rate (AAER) and improved lung function, asthma control, and health-related quality of life (HRQoL) in patients with severe, uncontrolled asthma (SUA) in the global, phase 3 NAVIGATOR study (NCT03347279). OBJECTIVE:DIRECTION was a phase 3, multicenter, double-blind study that assessed the efficacy and safety of tezepelumab in adults with SUA in China, the Philippines, and the Republic of Korea. METHODS:Patients (18-80 years old) with SUA (no baseline biomarker restrictions) were randomized 1:1 to receive tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. The primary end point was the AAER over 52 weeks. Key secondary end points were changes from baseline to week 52 in prebronchodilator forced expiratory volume in 1 second (FEV1) and Asthma Control Questionnaire-6 (ACQ-6), Asthma Quality of Life Questionnaire (standardized) for patients 12 years and older (AQLQ[S]+12), and Asthma Symptom Diary (ASD) scores. Safety was also assessed. RESULTS:Overall, 400 patients received tezepelumab (n = 201) or placebo (n = 199). Tezepelumab significantly reduced AAERs versus placebo by 74% (95% confidence interval [CI]: 61, 83; P < .001) in the overall population and by 60% (95% CI: 31, 77) in patients with baseline blood eosinophil count <300 cells/μL. Tezepelumab significantly improved prebronchodilator FEV1 (least-squares mean difference: 0.24 L [95% CI: 0.16, 0.32]) and ACQ-6, AQLQ(S)+12, and ASD scores at week 52 versus placebo (all P ≤ .001). No new safety concerns were identified. CONCLUSIONS:Tezepelumab reduced exacerbations and improved lung function, asthma control, and HRQoL in Asian patients with SUA, consistent with prior study findings.

Rationale: Tezepelumab is a human monoclonal antibody that blocks thymic stromal lymphopoietin (TSLP), an epithelial cytokine implicated in asthma pathogenesis. In the global phase 3 NAVIGATOR study (NCT03347279), tezepelumab significantly reduced the annualized asthma exacerbation rate (AAER) over 52 weeks compared with placebo in patients with severe, uncontrolled asthma overall and across categories of investigator-reported exacerbation triggers. In the DIRECTION study (NCT03927157), which assessed the efficacy and safety of tezepelumab in adults with severe, uncontrolled asthma in China, Republic of Korea and the Philippines, tezepelumab reduced the AAER over 52 weeks versus placebo by 74% (95% confidence interval [CI]: 61-83; p<0.001). This post hoc analysis assessed the effect of tezepelumab on exacerbations in patients grouped by investigator-reported exacerbation trigger categories in the DIRECTION study. Methods: DIRECTION was a phase 3, multicenter, randomized, double-blind, placebo-controlled study. Patients (18-80 years old) with severe, uncontrolled asthma receiving medium- or high-dose inhaled corticosteroids and at least one additional asthma controller medication, with or without oral corticosteroids, were randomized to receive tezepelumab 210 mg or placebo subcutaneously every 4 weeks for 52 weeks. There were no baseline biomarker restrictions in the inclusion criteria. The AAER over 52 weeks was assessed in patients grouped by the following exacerbation trigger categories, as reported by investigators in the electronic case report form: infection, noninfectious inhaled trigger exposure (e.g. weather, air pollution, cold or dry air), and other (e.g. work, food, medicine) or unknown exposure. Results: Overall, 400 patients received tezepelumab 210 mg (n=201) or placebo (n=199). Compared with placebo, tezepelumab reduced the AAER over 52 weeks by 50% (95% CI: 11-72) in exacerbations triggered by infection, by 78% (95% CI: 41-92) in exacerbations triggered by noninfectious inhaled trigger exposure and by 79% (95% CI: 63-88) in exacerbations triggered by other or unknown exposure (Figure). Conclusions: Consistent with findings from previous studies, tezepelumab reduced exacerbations across multiple exacerbation trigger categories in patients with severe, uncontrolled asthma in Asia.

Previous studies have shown that astrocyte activation in the anterior cingulate cortex (ACC), accompanied by upregulation of the astrocyte marker S100 calcium binding protein B (S100B), contributes to comorbid anxiety in chronic inflammatory pain (CIP), but the exact downstream mechanism is still being explored. The receptor for advanced glycation end-products (RAGE) plays an important role in chronic pain and psychosis by recognizing ligands, including S100B. Therefore, we speculate that RAGE may be involved in astrocyte regulation of the comorbidity between CIP and anxiety by recognizing S100B. Here, we investigated the potential role of RAGE and the correlation between RAGE and astrocyte regulation in the ACC using a mouse model of complete Freund's adjuvant (CFA)-induced inflammatory pain. We detected substantial upregulation of RAGE expression in ACC neurons when anxiety-like behaviors occurred in CFA-treated mice. The inhibition of RAGE expression decreased the hyperexcitability of ACC neurons and alleviated both hyperalgesia and anxiety in CFA-treated mice. Furthermore, we found that the ACC astrocytic S100B level increased over a similar time course. Intra-ACC application of S100B or downregulation of ACC astrocytic S100B via suppression of astrocyte activation significantly affected RAGE levels and the relative behaviors of CFA-treated mice. Taken together, these findings suggest that the upregulation of ACC neuronal RAGE results from the activation of astrocytic S100B and leads to the maintenance of pain perception and anxiety in the late phase after CFA injection, which may partly explain the mechanism by which ACC neuron‒astrocyte coupling promotes the maintenance of CIP and anxiety comorbidity.

Background: Analgesic tolerance due to long-term use of morphine remains a challenge for pain management. Morphine acts on mu-opioid receptors and downstream of the phosphatidylinositol 3-kinase signaling pathway to activate the mammalian target of rapamycin (mTOR) pathway. Rheb is an important regulator of growth and cell-cycle progression in the central nervous system owing to its critical role in the activation of mTOR. The hypothesis was that signaling via the GTP-binding protein Rheb in the dorsal horn of the spinal cord is involved in morphine-induced tolerance. Methods: Male and female wild-type C57BL/6J mice or transgenic mice (6 to 8 weeks old) were injected intrathecally with saline or morphine twice daily at 12-h intervals for 5 consecutive days to establish a tolerance model. Analgesia was assessed 60 min later using the tail-flick assay. After 5 days, the spine was harvested for Western blot or immunofluorescence analysis. Results: Chronic morphine administration resulted in the upregulation of spinal Rheb by 4.27 +/- 0.195-fold (P = 0.0036, n = 6), in turn activating mTOR by targeting rapamycin complex 1 (mTORC1). Genetic overexpression of Rheb impaired morphine analgesia, resulting in a tail-flick latency of 4.65 +/- 1.10 s (P < 0.0001, n = 7) in Rheb knock-in mice compared to 10 s in control mice (10 +/- 0 s). Additionally, Rheb overexpression in spinal excitatory neurons led to mTORC1 signaling overactivation. Genetic knockout of Rheb or inhibition of mTORC1 signaling by rapamycin potentiated morphine-induced tolerance (maximum possible effect, 52.60 +/- 9.56% in the morphine + rapamycin group vs. 16.60 +/- 8.54% in the morphine group; P < 0.0001). Moreover, activation of endogenous adenosine 5 '-monophosphate-activated protein kinase inhibited Rheb upregulation and retarded the development of morphine-dependent tolerance (maximum possible effect, 39.51 +/- 7.40% in morphine + metformin group vs. 15.58 +/- 5.79% in morphine group; P < 0.0001). Conclusions: This study suggests spinal Rheb as a key molecular factor for regulating mammalian target of rapamycin signaling.

Background:Post-spinal cord injury (SCI) inflammation correlates with neurologic recovery. Through sequencing, we explored the roles of a differentially expressed circRNA in mice after SCI, circGla, on inflammation and recovery of SCI. Methods:The T8-T10 SCI model was established in C57BL6 mice. HE staining and RT-qPCR verified circGla upregulation results after injury obtained through sequencing. RNase R digestion and primer amplification experiments confirmed the circular properties of circGla. Nucleus and cytoplasm isolation experiments and FISH confirmed circGla expression in the astrocyte cytoplasm. AAV was used to establish a circGla knockdown mouse model. Behavioral tests were conducted to assess the recovery of the neurological function. The key inflammatory molecules after SCI were evaluated through MRI, RT-qPCR, and ELISA. For in vitro experiments, circGla was upregulated or knocked down in mouse astrocytes to detect its effect. The binding between miR-488 and circGla was confirmed through RIP and the dual luciferase experiment. RT-qPCR and ELISA confirmed the content correlation of the two molecules and the in vitro inflammatory function of miR-488. The binding experiment in astrocytes confirmed the binding between miR-488 and MEKK1 mRNA. Western blotting of MAPK pathway-related proteins confirmed that MEKK1 is a downstream effector for circGla and miR-488 in astrocytes. Results:Following SCI, the circular RNA circGla levels increased and it existed in the astrocyte cytoplasm. circGla knockdown reduced inflammation and improved neurological recovery in vivo. The correlation between circGla and proinflammatory factors was confirmed in vitro. circGla bound to miR-488, and the high miR-488 level was associated with the low astrocyte inflammatory state. miR-488 bound to MEKK1 mRNA, and upregulation or knockdown of circGla or miR-488 affected MAPK pathway-related protein expression. Conclusion:Following SCI, downregulation of circGla expression in astrocytes can reduce inflammatory manifestations and stimulate long-term functional recovery in mice through miR-488 and MEKK1.

The activation of spinal astrocytes accounts for opioid-induced hyperalgesia (OIH), but the underlying mechanisms remain elusive. The presence of astrocyte-neuron lactate shuttle (ANLS) makes astrocytes necessary for some neural function and communication. The aim of this study was to explore the role of ANLS in the occurrence and maintenance of OIH. After 7 days consecutive morphine injection, a mice OIH model was established and astrocytic pyruvate dehydrogenase kinase 4 (PDK4), phosphorylated pyruvate dehydrogenase (p-PDH) and accumulation of L-lactate was elevated in the spinal dorsal horn. Intrathecally administration of inhibitors of PDK, lactate dehydrogenase 5 and monocarboxylate transporters to decrease the supply of L-lactate on neurons was observed to attenuate hypersensitivity behaviors induced by repeated morphine administration and downregulate the expression of markers of central sensitization in the spinal dorsal horns. The astrocyte line and the neuronal line were co-cultured to investigate the mechanisms in vitro. In this study, we demonstrated that morphine-induced hyperalgesia was sustained by lactate overload consequent upon aberrant function of spinal ANLS. In this process, PDK-p-PDH-lactate axis serves a pivotal role, which might therefore be a new target to improve long-term opioid treatment strategy in clinical practice.

吗啡镇痛效果显著,常用于慢性或剧烈性疼痛的治疗,但重复给药会发生镇痛效能降低并进展为吗啡耐受导致治疗中断,极大限制其临床应用.吗啡耐受的细胞和分子机制复杂.近年来,胶质细胞的激活和胶质细胞源性炎症介质的释放被发现在这一过程中发挥了重要作用.本文围绕神经胶质细胞参与并调控吗啡耐受的研究进展进行综述并总结新的治疗手段,为解决吗啡耐受问题或开发新型镇痛药物提供可能的思路与理论依据.

Analgesic tolerance due to long-term use of morphine remains a challenge for pain management. Morphine acts on μ-opioid receptors and downstream of the phosphatidylinositol 3-kinase signaling pathway to activate the mammalian target of rapamycin (mTOR) pathway. Rheb is an important regulator of growth and cell-cycle progression in the central nervous system owing to its critical role in the activation of mTOR. The hypothesis was that signaling via the GTP-binding protein Rheb in the dorsal horn of the spinal cord is involved in morphine-induced tolerance.Male and female wild-type C57BL/6J mice or transgenic mice (6 to 8 weeks old) were injected intrathecally with saline or morphine twice daily at 12-h intervals for 5 consecutive days to establish a tolerance model. Analgesia was assessed 60 min later using the tail-flick assay. After 5 days, the spine was harvested for Western blot or immunofluorescence analysis.Chronic morphine administration resulted in the upregulation of spinal Rheb by 4.27 ± 0.195-fold (P = 0.0036, n = 6), in turn activating mTOR by targeting rapamycin complex 1 (mTORC1). Genetic overexpression of Rheb impaired morphine analgesia, resulting in a tail-flick latency of 4.65 ± 1.10 s (P < 0.0001, n = 7) in Rheb knock-in mice compared to 10 s in control mice (10 ± 0 s). Additionally, Rheb overexpression in spinal excitatory neurons led to mTORC1 signaling overactivation. Genetic knockout of Rheb or inhibition of mTORC1 signaling by rapamycin potentiated morphine-induced tolerance (maximum possible effect, 52.60 ± 9.56% in the morphine + rapamycin group vs. 16.60 ± 8.54% in the morphine group; P < 0.0001). Moreover, activation of endogenous adenosine 5'-monophosphate-activated protein kinase inhibited Rheb upregulation and retarded the development of morphine-dependent tolerance (maximum possible effect, 39.51 ± 7.40% in morphine + metformin group vs. 15.58 ± 5.79% in morphine group; P < 0.0001).This study suggests spinal Rheb as a key molecular factor for regulating mammalian target of rapamycin signaling.

EDITORIAL article Front. Neurosci., 04 April 2023Sec. Neuropharmacology Volume 17 - 2023 | https://doi.org/10.3389/fnins.2023.1191030

Background: There is evidence of complement activation in asthma but its role remains unclear. Objective: To analyze the level of complement proteins in sputum by proteomics assay in the Chinese asthma cohort (C-BIOPRED). Method: Weighted gene correlation network analysis was used to define the unique modules that are highly correlated with clinical, physiologic and inflammatory traits. Results: A brown module was positive associated with blood eosinophil percentage (rho=0.38), blood eosinophil counts (rho=0.39), FeNO (rho=0.31), exacerbations (rho=0.13) and sputum eosinophil (%) (rho=0.48).The top enriched pathway of the brown module was complement and coagulation cascades.C5 and the C5 downstream proteins C6, C7, C8B, C8G and C9 were significantly up-regulated in the eosinophil-high group (sputum eosinophil % ≥ 2%). As a validation, sputum C5 and C9 levels were also up-regulated in the severe asthma U-BIOPRED eosinophil-high groups. Conclusion: Complement factors are highly expressed in and correlate with eosinophilic inflammation, supporting a role for the complement cascade in severe eosinophilic asthma.

To the Editor: Patients with severe persistent asthma experience greater morbidity with more impairment in quality of life despite higher use of health care resources and being treated with existing asthma treatments such as inhaled corticosteroids and β-agonists, and sometimes oral corticosteroid (OCS) therapy. Type-2 (T2) high asthma has been identified as a phenotype that responds to targeted T2 biologic therapies such as anti-IgE, anti-interleukin (IL) 5, or anti-IL5Rα and anti-IL4Rα monoclonal antibodies, which are currently available in Europe and North America, and are currently introduced in the rest of the world.[1] Although the prevalence of adult asthma of 4.2% in China is not as high as that in Western countries, severe asthma as defined according to the European Respiratory Society and America Thoracic Society (ERS/ATS) definition is being recognized.[2] The Chinese Biomarkers for the Prediction of Respiratory Disease Outcomes (C-BIOPRED) cohort of 452 severe asthma patients has characterized these patients that share similar features as those reported in cohorts outside China.[3] To understand the potential impact of T2-targeted biologic therapies in China, we have determined the prevalence of T2-high asthma based on the criteria of blood eosinophil count (BEC) of either ≥150/μL or ≥300/μL and/or FeNO ≥20 parts per billion (ppb) (https://ginasthma.org/wp-content/uploads/2021/08/SA-Pocket-guide-v3.0-SCREEN-WMS.pdf). Data are presented as mean (standard deviation) or number of subjects (% of total). P values represent comparison across four groups using Kruskal–Wallis tests for continuous variables or Fisher exact tests for categorical variables. P < 0.05 was considered to be statistically significant. T2-high was present ranging from 55.8% (BEC ≥300 μL) to 75.7% (FeNO ≥20 ppb) of the severe asthma patients, while a combination of BEC ≥150/μL and FeNO ≥20 ppb or BEC ≥300/μL and FeNO ≥20 ppb identified 55.9% and 38.7%, respectively [Supplementary Figure 1, https://links.lww.com/CM9/B402]. In 246 severe asthma patients who were re-assessed at one year, a similar percentage of patients remained T2-high, but 10% to 15% in T2-high or T2-low changed to the alternate class. Sputum eosinophil count (SEC) is a better marker of T2-high asthma,[4] and using a SEC ≥2%,[5] 75% of patients were classified as T2-high. To determine the eligibility for T2 biologic therapies, we used the guidelines of the Global Initiative for Asthma (GINA) (https://ginasthma.org/wp-content/uploads/2021/08/SA-Pocket-guide-v3.0-SCREEN-WMS.pdf), whereby patients diagnosed with severe asthma have had at least two exacerbations in the past year with biomarker cut-offs for different classes of biologic therapies. For anti-IgE antibody, we used the presence of sensitization on skin prick testing or specific IgE to common aeroallergens with total serum IgE and body weight within the dosage range. For anti-IL5 or anti-IL5Rα, BEC of ≥300/μL, and for anti-IL4Rα, BEC ≥150/μL or FeNO ≥25 ppb were used. Among 452 patients with severe asthma, 174 (38.5%) were eligible for one or more of the three biologic treatments [Figure 1]. A total of 51 cases (11.3%) were eligible for anti-IgE treatment, but eight (1.8%) individuals were only eligible for anti-IgE therapy. Similarly, 166 cases (36.7%) were eligible for anti-IL4Rα treatment, but 60 (13.3%) were only eligible for this treatment. There were 87 patients (19.3%) suitable for anti-IL-5/5Rα treatment, but all of whom would also be eligible for anti-IL4Rα treatment [Supplementary Table 1, https://links.lww.com/CM9/B402]. Besides, 63 (13.9%) patients were included for being both eligible for anti-IL4R and anti-IL-5/5Rα groups, and 43 (9.5%) patients were both eligible for anti-IgE and anti-IL4R therapy [Figure 1]. Finally, 24 cases (5.3%) met the three treatment standards for either anti-IgE or anti-IL4R or anti-IL-5/5R antibody.Figure 1: Venn diagram of severe asthmatics eligible for treatment with anti-IgE, or anti-IL5/IL5Rα or anti-IL4Rα monoclonal antibodies. IL: Interleukin.As shown in Supplementary Table 2, [https://links.lww.com/CM9/B402], compared with other groups, patients who would qualify only for anti-IgE had the better controlled asthma, lowest FeNO value (5.61 ppb, P < 0.001), lowest serum BEC, ECP, and total IgE levels, and none required daily OCS therapy. By contrast, those eligible for anti-IL4Rα only had higher BEC (540/μL, P < 0.001), higher FeNO, and highest sputum eosinophilia (33.3%) and comprised of the highest percentage of OCS patients (31.2%). Those eligible for all three biologic treatments had highest total serum IgE (449.75 KU/L, P < 0.001) and ECP levels than the other patients eligible for anti-IgE alone or for anti-IL4Rα alone. Patients not eligible for any biologic treatments were characterized by the highest FeNO (33.2 ppb, P < 0.001), with raised sputum eosinophils and BEC (270/μL) and none received OCS therapy. Because the UK National Health and Care Institute has advocated the use of these biologics using different criteria (https://www.nice.org.uk/guidance/TA751/chapter/1-Recommendations), we have examined these conditions such as the need for having more than four severe exacerbations in the previous year and the combination of BEC ≥150/μL plus FeNO ≥25 ppb for consideration of severe asthma patients for anti-IL4Rα. Thus, extending the cut-off point of 1, 2, 3, or 4 exacerbations in the previous year, those eligible for the biologic therapies would be 58.8%, 38.5%, 23.0%, and 15.3%, respectively [Supplementary Table 1, https://links.lww.com/CM9/B402]. In addition, using the combination of BEC ≥150/μL and FeNO ≥25 ppb instead of BEC ≥150/μL or FeNO ≥25 ppb for anti-IL4Rα allowed for a greater percentage of patients that would be eligible for anti-IgE and anti-IL5/IL5Rα antibody treatments, at the expense of anti-IL4Rα antibody only. Interestingly, those with more than one exacerbation per year and using eligibility for anti-IL4Rα as the combination of BEC ≥150/μL and FeNO ≥25 ppb maximizes the numbers that would be suitable for only one of the three classes of antibodies (anti-IgE: 7.5%, anti-IL5/IL5Rα: 5.3%, and anti-IL4Rα: 10.0%). The T2-high severe asthma phenotype that is relatively stable in up to 80.0% and up to 58.8% of severe asthma would be eligible for biologic therapies, dependent on the criteria used. These definitions are all dependent on the cut-off point of the biomarker used, usually a BEC. The largest group to benefit is that eligible for anti-IL4Rα targeting both IL-4 and IL-13, who have the highest blood and sputum eosinophilia, with a large proportion of atopic patients. Those eligible for IL5/IL5Rα biologic are also eligible for anti-IL-4Rα, which indicates the need for more refined biomarkers that would distinguish eligibility for each specific biologic therapy. Finally, many of the 42.0% of severe asthma patients not eligible for biologic therapies represent those who do not report two or more exacerbations in the previous year, particularly in those with atopy and high BECs. Using the experience of at least four exacerbations, only a minority of severe asthmatics (∼15% only) would be eligible for these biologic therapies. In conclusion, this study reveals that T2-high asthma is the predominant phenotype in patients with severe asthma in the C-BIOPRED cohort and remains relatively stable after a 1-year longitudinal visit. In addition, we found that the proportion of patients for whom different T2 biologic therapies were indicated varied, depending on entry criteria, and that more refined biomarkers that would distinguish eligibility for each specific biologic therapy were needed. Acknowledgements We would like to thank all the members of the C-BIOPRED Study Group who were involved in the design and recruitment of participants into the study. We thank Yicheng Fan, Yujing Liu, Nkouibert Pryseley Assam, Zhaohui Zhou, Wei Jiang, and Jia Wang of Astra-Zeneca for their help in data and statistical analyses and in the preparation of the figures and tables. We also thank all the participants who willingly took part in the C-BIOPRED study. Funding This study was supported by grants from Astra-Zeneca, China, and the National Natural Science Foundation of China (No. 82070026). Conflicts of interest Kian Fan Chung has received honoraria for participating in Advisory Board meetings of GSK, AZ, Roche, Merck, Nocion, and Shionogi regarding treatments for asthma, chronic obstructive pulmonary disease, and chronic cough and has also been remunerated for speaking engagements for AZ. The other authors declare no conflict of interest. Ethics statement The study was approved by the Institutional Ethics Committee of the First Affiliated Hospital of Guangzhou Medical University (No. 201525) and written informed consents were obtained from all participants. Data availability statement The data that support the findings of this study are available from the corresponding author upon reasonable request.