Disease Course and Treatment Response of Eosinophilic Gastrointestinal Diseases in Children With Liver Transplantation: Long-Term Follow-Up.

INTRODUCTION: To describe the clinical and laboratory profile, natural course, treatment outcome, and risk factors of posttransplant esophageal and nonesophageal eosinophilic gastrointestinal disorders (EGIDs). METHODS: All children (aged <18 years) who underwent liver transplantation, between 2011 and 2019, in a single transplant center with a follow-up period of 1 year or more posttransplant and with a history of posttransplant endoscopic evaluation were included in this study. RESULTS: During the study period, 89 children met the inclusion criteria. Patients were followed for a median of 8.0 years. A total of 39 (44%) patients were diagnosed with EGID after transplantation. Of these, 29 (33%) had eosinophilic esophagitis (EoE), and 10 (11%) had eosinophilic gastritis, gastroenteritis or enterocolitis. In comparison with the non-EGID group, patients with EGID were younger at transplant (P ≤ 0.0001), transplanted more frequently due to biliary atresia (P ≤ 0.0001), and had higher rates of pretransplant allergy (P = 0.019). In the posttransplant period, they had higher rates of mammalian Target of Rapamycin inhibitor use (P = 0.006), Epstein-Barr virus viremia (P = 0.03), post-transplant lymphoproliferative disease (P = 0.005), and allergen sensitization (P ≤ 0.0001). In regression analysis, young age at transplant, age at diagnosis, pretransplant atopic dermatitis, and post-transplant lymphoproliferative disease were associated with an increased risk of EGID or EoE. Laboratory abnormalities such as anemia (P = 0.007), thrombocytosis (P = 0.012), and hypoalbuminemia (P = 0.031) were more commonly observed in the eosinophilic gastritis, gastroenteritis or enterocolitis group than in the EoE group. Following treatment, most patients had symptomatic resolution at 3 months and histologic resolution at 6 months postdiagnosis. Among the patients who had 5 years of follow-up, none recurred. DISCUSSION: EGID is a common posttransplant diagnosis, which seems to affect patients who are transplanted earlier and who have pretransplant atopy. Posttransplant EGID is responsive to treatment, but as histologic remission occurs after symptomatic resolution, the decision to perform control endoscopy should be delayed.

Outdoor pollen-related changes in lung function and markers of airway inflammation: A systematic review and meta-analysis.

BACKGROUND: Experimental challenge studies have shown that pollen can have early and delayed effects on the lungs and airways. Here, we qualitatively and quantitatively synthesize the evidence of outdoor pollen exposure on various lung function and airway inflammation markers in community-based studies. METHODS: Four online databases were searched: Medline, Web of Science, CINAHL and Google Scholar. The search strategy included terms relating to both exposure and outcomes. Inclusion criteria were human-based studies published in English that were representative of the community. Additionally, we only considered cross-sectional or short-term longitudinal studies which investigated pollen exposure by levels or season. Study quality assessment was performed using the Newcastle-Ottawa scale. Meta-analysis was conducted using random-effects models. RESULTS: We included 27 of 6551 studies identified from the search. Qualitative synthesis indicated associations between pollen exposure and predominantly type-2 inflammation in both the upper and lower airways, but little evidence for lung function changes. People with ever asthma and/or seasonal allergic rhinitis (SAR) were at higher risk of such airway inflammation. Meta-analysis confirmed a positive relationship between pollen season, eosinophilia and eosinophil cationic protein (ECP) in people with ever SAR but the results between studies were highly variable. Heterogeneity was reduced after further subgrouping by age, and the forest plots indicated that eosinophilic airway inflammation to outdoor pollen exposure increased with age. CONCLUSION: Among people with ever asthma and ever SAR, exposure to increased ambient pollen triggers type-2 upper and lower airway inflammation rather than a non-specific or innate inflammation. These findings can lead to the formulation of specific pollen immunotherapy for susceptible individuals. Future research should be directed towards investigating lagged associations and effect modifications using larger and more generalized populations. SYSTEMATIC REVIEW REGISTRATION: CRD42020146981 (PROSPERO).

Genetic Variation in Surfactant Protein-A2 Delays Resolution of Eosinophilia in Asthma.

Surfactant protein-A (SP-A) is an important mediator of pulmonary immunity. A specific genetic variation in SP-A2, corresponding to a glutamine (Q) to lysine (K) amino acid substitution at position 223 of the lectin domain, was shown to alter the ability of SP-A to inhibit eosinophil degranulation. Because a large subgroup of asthmatics have associated eosinophilia, often accompanied by inflammation associated with delayed clearance, our goal was to define how SP-A mediates eosinophil resolution in allergic airways and whether genetic variation affects this activity. Wild-type, SP-A knockout (SP-A KO) and humanized (SP-A2 223Q/Q, SP-A2 223K/K) C57BL/6 mice were challenged in an allergic OVA model, and parameters of inflammation were examined. Peripheral blood eosinophils were isolated to assess the effect of SP-A genetic variation on apoptosis and chemotaxis. Five days postchallenge, SP-A KO and humanized SP-A2 223K/K mice had persistent eosinophilia in bronchoalveolar lavage fluid compared with wild-type and SP-A2 223Q/Q mice, suggesting an impairment in eosinophil resolution. In vitro, human SP-A containing either the 223Q or the 223K allele was chemoattractant for eosinophils whereas only 223Q resulted in decreased eosinophil viability. Our results suggest that SP-A aids in the resolution of allergic airway inflammation by promoting eosinophil clearance from lung tissue through chemotaxis, independent of SP-A2 Q223K, and by inducing apoptosis of eosinophils, which is altered by the polymorphism.

Real-life evaluation of mepolizumab efficacy in patients with severe eosinophilic asthma, according to atopic trait and allergic phenotype.

BACKGROUND: Anti-interleukin-5 (IL-5) monoclonal antibodies can be used as add-on biological therapies in allergic and non-allergic patients with severe eosinophilic asthma. However, within such a therapeutic context real-life investigations are lacking. OBJECTIVE: Therefore, the aim of the present observational study was to evaluate the effects of mepolizumab in allergic and non-allergic subjects with severe eosinophilic asthma. METHODS: Relevant clinical, functional, laboratory, and pharmacotherapeutic parameters were assessed in the above patient subgroups. RESULTS: After one year of add-on biological treatment with mepolizumab, our 88 patients experienced a remarkable improvement of their severe asthma, documented by a better symptom control, expressed by a significant improvement in asthma control test (ACT) score. Indeed, the mean value (±standard deviation) of ACT score increased from 12.55 (±3.724) to 21.08 (±3.358). Moreover, significant improvements were also detected with regard to the median values (interquartile range) of forced expiratory volume in one second (FEV1 ), blood eosinophil numbers, annual rate of disease exacerbations, and daily intake of oral corticosteroids (OCS). In particular, FEV1 enhanced from 1640 mL (1110-2275) to 1920 mL (1525-2615), blood eosinophil count dropped from 711.0 cells/µL (500.0-1022) to 90.00 cells/µL (50.00-117.5), the annual rate of asthma exacerbations decreased from 3.000 (2.000-6.000) to 0.000 (0.000-1.000), and the daily prednisone intake fell from 6.250 mg (0.000-25.00) to 0.000 mg (0.000-0.000). After one year of mepolizumab treatment, the improvements in clinical, functional, and haematological parameters were quite similar in patient subgroups characterized by skin prick test (SPT) negativity or positivity, respectively. A significant correlation was observed between serum IgE levels and OCS intake decrease (r = -0.2257; P < .05). CONCLUSION AND CLINICAL RELEVANCE: Hence, our real-life data suggest that mepolizumab can represent a valid add-on therapeutic option for patients with severe eosinophilic asthma, irrespective of IgE serum concentrations, and allergic sensitization.

Understanding the immunology of asthma: Pathophysiology, biomarkers, and treatments for asthma endotypes.

Asthma is a common disease in paediatrics and adults with a significant morbidity, mortality, and financial burden worldwide. Asthma is now recognized as a heterogeneous disease and emerging clinical and laboratory research has elucidated understanding of asthma's underlying immunology. The future of asthma is classifying asthma by endotype through connecting discernible characteristics with immunological mechanisms. This comprehensive review of the immunology of asthma details the currently known pathophysiology and clinical practice biomarkers in addition to forefront biologic and targeted therapies for all of the asthma endotypes. By understanding the immunology of asthma, practitioners will be able to diagnose patients by asthma endotype and provide personalized, biomarker-driven treatments to effectively control patients' asthma.

Short-term use of "ECMELLA" in the context of fulminant eosinophilic myocarditis with cardiogenic shock.

BACKGROUND: Eosinophilic myocarditis (EM) is a rare form of myocarditis. Clinical presentation is various, includes cardiogenic shock and can often be fatal. Diagnosis is based on myocardial eosinophilic infiltration in endomyocardial biopsy. Mechanical circulatory support (MCS) is often required in patients suffering from severe cardiogenic shock. Among the available MCS options the "ECMELLA" concept, a combination of left ventricular venting by Impella® device and extracorporeal life support (ECLS) is possibly able to provide the necessary time frame for diagnostics and initiation of anti-inflammatory medication in patients with fulminant myocarditis. CASE PRESENTATION: We report a case of a 38-year-old woman who was presented to us in severe cardiogenic shock, quickly requiring hemodynamic support by an Impella CP® device. Further dramatic hemodynamic deterioration accompanied by multi-organ dysfunction required escalation of MCS via ECLS as veno-arterial extracorporeal membrane oxygenation (VA-ECMO). After histopathological diagnosis of EM, our patient was put on immunosuppressive therapy with prednisolone. Recovery of both right and left ventricular function allowed explanation of VA-ECMO on day 4 and further hemodynamic improvement allowed removal of the Impella® device on day 9. The patient was discharged after 7 weeks with fully restored cardiac function and in a good neurological state. CONCLUSIONS: In severe cardiac shock due to fulminant EM the ECMELLA concept as bridge-to-recovery seems to be a valid option to provide the required time for diagnostics and specific therapy.

Relationship of Blood Eosinophils with Fractional Exhaled Nitric Oxide and Pulmonary Function Parameters in Chronic Obstructive Pulmonary Disease (COPD) Exacerbation.

BACKGROUND The 2018 Global Initiative for Chronic Obstructive Lung Disease Report reveals that the blood eosinophil count could forecast the risk of flare-ups. This study explored the correlations of blood eosinophils with fractional exhaled nitric oxide (FeNO) and pulmonary function parameters in acute exacerbation of chronic obstructive pulmonary disease (AECOPD). MATERIAL AND METHODS The data of patients with AECOPD at our hospital admitted between July 2018 and June 2019 were retrospectively analyzed. All patients were stratified into an eosinophilic group (≥2%) or a noneosinophilic group (<2%) based on the peripheral eosinophil count per centum. Cross-sectional analysis was performed to compare clinical characteristics, percentage of eosinophils, FeNO, and pulmonary function between the 2 groups. RESULTS After applying the inclusion/exclusion criteria, 247 patients were included. FeNO values were higher in eosinophilic group (n=97) than in noneosinophilic group (n=150) (P=0.005). The forced expiratory volume in 1 second% predicted (FEV1% predicted), FEV1, and forced vital capacity (FVC) were higher in the eosinophilic group than in the noneosinophilic group (P=0.043; P=0.040; and P=0.011, respectively). Blood eosinophilia showed positive correlations with FeNO (P=0.004) and spirometry variables (FEV1 [% predicted], P=0.003; FEV1, P<0.001; and FVC, P<0.001). An FeNO level of 22.5 ppb was the best cutoff value to predict blood eosinophilia (P=0.000). CONCLUSIONS Blood eosinophil count is a likely biomarker that can predict positive relationship with FeNO values and pulmonary function parameters.

Effect of Anti-IL5, Anti-IL5R, Anti-IL13 Therapy on Asthma Exacerbations: A Network Meta-analysis.

BACKGROUND: Several new treatments for severe asthma have become available in the last decade; yet, little data exist to guide their use in specific patient populations. OBJECTIVE: A network meta-analysis was conducted comparing the efficacy of FDA-approved monoclonal antibody therapies in preventing exacerbations in patients with severe eosinophilic asthma. METHODS: PubMed and Ovid were searched from inception until July 2019 for randomized controlled trials that studied the efficacy of benralizumab, dupilumab, mepolizumab, and reslizumab, in preventing acute exacerbations of asthma. Studies were included if they reported data for patients with severe eosinophilic asthma (defined in this meta-analysis as absolute eosinophil count ≥ 250 cells/µL). Annualized rate ratios for asthma exacerbations (during treatment) were calculated and converted to log rate ratios. Direct and indirect treatment estimates (for inter-drug differences) were analyzed using frequentist network meta-analysis methodology in R and treatments were ranked based on P-scores. RESULTS: In total, nine studies were included in the final analysis. Network meta-analysis revealed that all drugs were superior to placebo in preventing rates of asthma exacerbation in the study population and no inter-drug differences existed. Dupilumab was found to have the greatest magnitudes of effect on decreasing log rate ratio of asthma exacerbation based on P-score (0.83). CONCLUSION: Benralizumab, dupilumab, mepolizumab, and reslizumab are all associated with decreased asthma exacerbations in patients with eosinophilic asthma, with no significant inter-drug differences.

Stratification of asthma phenotypes by airway proteomic signatures.

BACKGROUND: Stratification by eosinophil and neutrophil counts increases our understanding of asthma and helps target therapy, but there is room for improvement in our accuracy in prediction of treatment responses and a need for better understanding of the underlying mechanisms. OBJECTIVE: We sought to identify molecular subphenotypes of asthma defined by proteomic signatures for improved stratification. METHODS: Unbiased label-free quantitative mass spectrometry and topological data analysis were used to analyze the proteomes of sputum supernatants from 246 participants (206 asthmatic patients) as a novel means of asthma stratification. Microarray analysis of sputum cells provided transcriptomics data additionally to inform on underlying mechanisms. RESULTS: Analysis of the sputum proteome resulted in 10 clusters (ie, proteotypes) based on similarity in proteomic features, representing discrete molecular subphenotypes of asthma. Overlaying granulocyte counts onto the 10 clusters as metadata further defined 3 of these as highly eosinophilic, 3 as highly neutrophilic, and 2 as highly atopic with relatively low granulocytic inflammation. For each of these 3 phenotypes, logistic regression analysis identified candidate protein biomarkers, and matched transcriptomic data pointed to differentially activated underlying mechanisms. CONCLUSION: This study provides further stratification of asthma currently classified based on quantification of granulocytic inflammation and provided additional insight into their underlying mechanisms, which could become targets for novel therapies.

Bronchoscopic features, associations, and outcomes of organizing pneumonia following allogeneic hematopoietic stem cell transplantation.

Organizing pneumonia (OP) is a poorly understood complication of hematopoietic stem cell transplant (HSCT). We identified 15 patients diagnosed with OP following HSCT and described their clinical course. CT chest findings were remarkable for multifocal infiltrates that were predominantly consolidating or ground glass opacities. Bronchoalveolar lavage (BAL) was performed on 14 patients with five having lymphocytosis (> 25% lymphocytes), three with eosinophilia (> 5% eosinophils), three with neutrophilia (> 30% neutrophils), and three with normal cell counts. Flow cytometry was analyzed on BAL fluid in 13 patients with 11 having a CD4/CD8 of < 0.9. Initial treatment with 0.3-1.0 mg/kg prednisone resulted in improvement in symptoms, in radiographic findings, and in pulmonary function testing for the majority of patients. Six patients had recurrence of OP after completing treatment. Eleven patients had evidence of extra-pulmonary graft-versus-host disease prior to diagnosis of OP, and seven patients were diagnosed with an upper respiratory tract infection (URI) within 8 weeks of OP diagnosis. Most patients respond well to prednisone with significant improvement in pulmonary function, but risk of recurrence is high after cessation of steroid treatment. Risk factors for the development of OP may include prior URI.

Analysis of the drop-out rate in patients receiving mepolizumab for severe asthma in real life.

Mepolizumab (anti IL-5, monoclonal antibody) is commercially available in Italy since more than one year for the treatment of severe hypereosinophilic asthma. Its efficacy and safety were evaluated in several regulatory trials. The characteristics of this drug in real life began to be assessed only recently. We describe herein the drop-out rate observed with mepolizumab in real life, because this datum can indirectly reflect the safety and tolerability aspects. The demographic and clinical data of patients receiving mepolizumab for severe asthma were collected, and the number and reasons for discontinuation of the treatment were analyzed. The database involves 143 patients (67 male, age range 19-80 year) who received at least one dose of mepolizumab. The observed discontinuation rate was 6/143 (4.2%). Five out of 6 discontinuations were due to lack of response, and one was an adverse event (urticaria) probably related to the treatment. There was no clinical difference between the drop-out group and the patients still ongoing. As compared to the clinical trials published the discontinuation rate was lower in our population, especially for adverse events (7% vs 23.7%). Thus, the tolerability of mepolizumab, as derived from discontinuations, seems to be better in real-life than in clinical trials.

Rapid onset of effect of benralizumab on morning peak expiratory flow in severe, uncontrolled asthma.

BACKGROUND: Benralizumab is a unique eosinophil-depleting monoclonal antibody that significantly reduces asthma exacerbations, improves lung function and asthma symptoms, and permits the reduction of maintenance oral corticosteroid dosage for patients with severe, uncontrolled eosinophilic asthma. OBJECTIVE: To assess benralizumab's onset of action and efficacy by examining change in morning peak expiratory flow (PEF) after initiation of treatment in the phase 3 clinical trials SIROCCO, CALIMA, and ZONDA. METHODS: Mixed-model repeated-measures analysis was used to calculate PEF using daily least squares mean changes from baseline in morning PEF as well as differences between the benralizumab every 8 weeks (first 3 doses every 4 weeks) and placebo groups. A Bayesian nonlinear mixed-effects approach with an exponential relationship was used to model trial data to determine time to clinically meaningful improvement in morning PEF (defined as ≥25 L/min). RESULTS: Least squares mean morning PEF improvement from baseline was numerically greater by Day 2 after initiation of benralizumab therapy in all 3 trials. The Bayesian nonlinear mixed-effects model indicated that PEF improvement reached the clinically meaningful threshold within 3 weeks in SIROCCO and CALIMA and 2 weeks in ZONDA. CONCLUSION: In 3 phase 3 randomized clinical trials, benralizumab provided notable improvement in morning PEF 2 days after initiation and clinically meaningful improvements within 3 weeks for patients with severe, uncontrolled eosinophilic asthma. The rapid improvement in PEF demonstrated in these trials suggests that benralizumab's unique mechanism of action rapidly improves lung function for patients with severe, eosinophilic asthma. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT01928771 (SIROCCO), NCT01914757 (CALIMA), and NCT02075255 (ZONDA).

Vancomycin-associated drug-induced hypersensitivity syndrome.

BACKGROUND: Although hypersensitivity reactions are well characterized for certain medications, vancomycin-associated drug-induced hypersensitivity syndrome (DIHS), or drug reaction with eosinophilia and systemic symptoms (DRESS), has yet to be defined. OBJECTIVE: To better define the clinical phenotype of vancomycin-associated DIHS. METHODS: A retrospective case series was conducted over an 8-year period at a single, academic institution. A total of 29 cases of DIHS/DRESS were identified, of which 4 were attributed to vancomycin. A literature review was performed; it identified 28 additional cases of vancomycin-induced DIHS. Vancomycin-associated acute interstitial nephritis was also reviewed to detect additional, previously uncharacterized cases of systemic hypersensitivity. The review yielded 11 additional cases. RESULTS: In this literature review and retrospective series, the incidence of renal dysfunction among vancomycin-induced cases (75% and 68% of cases in the series and literature, respectively) was notably higher than the overall reported incidence in DIHS (10%-40%). The degree of renal impairment was also significantly increased in the retrospective series (a median 4.98-fold change in baseline creatinine level vs a 2.25-fold increase in non-vancomycin-associated cases [P = .011]). LIMITATIONS: The principal limitation of this study is the small sample size. Other notable limitations include the retrospective nature of the study and absence of confirmatory renal biopsies. CONCLUSION: Although the current understanding of DIHS/DRESS is imperfect, our findings suggest that vancomycin-induced cases present with a unique phenotype characterized by a higher burden of renal involvement.

Steroid-resistant eosinophilic fasciitis successfully treated with addition of extracorporeal photopheresis.

Eosinophilic fasciitis (EF) is an uncommon fibrosing disease of the fascia with characteristic cutaneous and hematologic manifestations. Although EF is most commonly treated with corticosteroids at the beginning, a considerable number of patients show an inadequate response and hence various therapeutic strategies have been tried, including extracorporeal photopheresis (ECP). We describe the case of a 66-year-old woman with steroid-resistant EF that improved significantly after ECP was added to her treatment regimen. To date, only six cases of this therapeutic strategy have been reported in English literature.

Prospective Open-Label Study of 48-Week Subcutaneous Administration of Mepolizumab in Japanese Patients With Severe Eosinophilic Asthma.

BACKGROUND: The long-term efficacy and safety of mepolizumab in patients with severe eosinophilic asthma has been evaluated in large-scale double-blind placebo-controlled trials. However, a prospective open-label trial of long-term subcutaneous administration of mepolizumab has not been performed in Japanese patients with severe eosinophilic asthma. METHODS: This study was a prospective, 48-week, open-label trial in 32 Japanese patients with severe eosinophilic asthma who received subcutaneous mepolizumab 100 mg every 4 weeks. Nine patients required oral corticosteroids daily despite receiving high-dose inhaled corticosteroids. Six patients had aspirin-exacerbated respiratory disease. RESULTS: All patients took mepolizumab throughout the study period. No patients experienced adverse events during the treatment. None of the patients experienced asthma exacerbations during the trial. In fact, forced expiratory volume in 1 second increased significantly at 24 weeks (P<.01) and at 48 weeks (P<.05). The peripheral blood eosinophil count in peripheral blood decreased after the first administration of mepolizumab in all patients and remained low until week 48. After starting mepolizumab, all oral corticosteroid-dependent asthmatics successfully withdrew corticosteroids without exacerbations and experienced a sustained reduction in peripheral blood eosinophil count. Blood levels of thymus and activation-regulated chemokine and IgE remained unchanged after 48 weeks of therapy with mepolizumab. CONCLUSION: This first prospective open-label pilot study in Japan demonstrated the long-term efficacy and safety of mepolizumab in patients with severe eosinophilic asthma.

Sputum Eosinophilia and Magnetic Resonance Imaging Ventilation Heterogeneity in Severe Asthma.

RATIONALE: Inflammation and smooth muscle dysfunction are integral components of severe asthma that contribute to luminal obstruction causing airflow limitation, ventilation heterogeneity, and symptoms. This is important for guiding treatment decisions directed at the inflammatory (e.g., anti-T-helper cell type 2 monoclonal antibodies) and noninflammatory, smooth muscle-mediated (e.g., bronchial thermoplasty) components of severe asthma. OBJECTIVES: To investigate the contribution of eosinophilic bronchitis and smooth muscle dysfunction to magnetic resonance imaging (MRI) ventilation heterogeneity in patients with severe asthma. METHODS: We measured the inhaled hyperpolarized gas MRI response to salbutamol as a marker of smooth muscle dysfunction, and sputum eosinophils as a marker of airway inflammation, and their contributions to ventilation heterogeneity (quantified as the ventilation defect percent [VDP]) in 27 patients with severe asthma. Spirometry and forced oscillation airway resistance measurements were also acquired pre- and postsalbutamol. Patients were dichotomized on the basis of sputum eosinophilia, and pre- and postsalbutamol VDP and physiological measurements were evaluated. MEASUREMENTS AND MAIN RESULTS: MRI VDP improved with salbutamol inhalation in patients in whom sputum eosinophilia was uncontrolled (≥3%, n = 16) (P = 0.002) and in those in whom it was controlled (<3%, n = 11) (P = 0.02), independent of improvements in FEV1, indicating smooth muscle response. In those patients in whom sputum eosinophilia was uncontrolled, greater VDP persisted postsalbutamol (P = 0.004). Postsalbutamol VDP correlated with sputum eosinophils (r = 0.63; P = 0.005). CONCLUSIONS: In patients with severe asthma, MRI regionally identifies the inflammatory and noninflammatory components of airway disease. Ventilation heterogeneity persists postsalbutamol in patients with uncontrolled eosinophilic bronchitis, which may be the functional consequence of airway inflammation.

Ethosuximide-induced drug reaction with eosinophilia and systemic symptoms with mediastinal lymphadenopathy.

Lymphadenopathy is a common sign for drug reaction and eosinophilia with systemic symptoms (DRESS) syndrome, but hilar and mediastinal lymphadenopathy may be underreported. We describe a 7-year-old boy who started taking ethosuximide for absence seizures and presented with diffuse rash, fever, elevated transaminases, facial swelling, and hilar and mediastinal lymphadenopathy. His mediastinal lymphadenopathy was concerning for lymphoma, which led to more invasive testing to rule out malignancy. This report highlights an unusual and likely underreported presenting sign of DRESS syndrome in children.

Low-density lipoprotein receptor-related protein 1 attenuates house dust mite-induced eosinophilic airway inflammation by suppressing dendritic cell-mediated adaptive immune responses.

BACKGROUND: Low-density lipoprotein receptor-related protein 1 (LRP-1) is a scavenger receptor that regulates adaptive immunity and inflammation. LRP-1 is not known to modulate the pathogenesis of allergic asthma. OBJECTIVE: We sought to assess whether LRP-1 expression by dendritic cells (DCs) modulates adaptive immune responses in patients with house dust mite (HDM)-induced airways disease. METHODS: LRP-1 expression on peripheral blood DCs was quantified by using flow cytometry. The role of LRP-1 in modulating HDM-induced airways disease was assessed in mice with deletion of LRP-1 in CD11c+ cells (Lrp1fl/fl; CD11c-Cre) and by adoptive transfer of HDM-pulsed CD11b+ DCs from Lrp1fl/fl; CD11c-Cre mice to wild-type (WT) mice. RESULTS: Human peripheral blood myeloid DC subsets from patients with eosinophilic asthma have lower LRP-1 expression than cells from healthy nonasthmatic subjects. Similarly, LRP-1 expression by CD11b+ lung DCs was significantly reduced in HDM-challenged WT mice. HDM-challenged Lrp1fl/fl; CD11c-Cre mice have a phenotype of increased eosinophilic airway inflammation, allergic sensitization, TH2 cytokine production, and mucous cell metaplasia. The adoptive transfer of HDM-pulsed LRP-1-deficient CD11b+ DCs into WT mice generated a similar phenotype of enhanced eosinophilic inflammation and allergic sensitization. Furthermore, CD11b+ DCs in the lungs of Lrp1fl/fl; CD11c-Cre mice have an increased ability to take up HDM antigen, whereas bone marrow-derived DCs display enhanced antigen presentation capabilities. CONCLUSION: This identifies a novel role for LRP-1 as a negative regulator of DC-mediated adaptive immune responses in the setting of HDM-induced eosinophilic airway inflammation. Furthermore, the reduced LRP-1 expression by circulating myeloid DCs in patients with eosinophilic asthma suggests a possible role for LRP-1 in modulating type 2-high asthma.

A bispecific antibody strategy to target multiple type 2 cytokines in asthma.

BACKGROUND: Asthma is a chronic inflammatory airway disease in which innate and adaptive immune cells act together to cause eosinophilic inflammation, goblet cell metaplasia (GCM), and bronchial hyperreactivity (BHR). In clinical trials using biologicals against IL-4 receptor (IL-4R) α or IL-5, only a subset of patients with moderate-to-severe asthma responded favorably, suggesting that distinct pathophysiologic mechanisms are at play in subgroups of patients called endotypes. However, the effect of multiple cytokine blockade using bispecific antibodies has not been tested. OBJECTIVE: We sought to target simultaneously the IL-4, IL-13, and IL-5 signaling pathways with a novel IL-4Rα/IL-5-bispecific antibody in a murine house dust mite (HDM) model of asthma. METHODS: Two mAbs neutralizing IL-4Rα and IL-5 were generated by using a llama-based antibody platform. Their heavy and light chains were then cotransfected in mammalian cells, resulting in a heterogeneous antibody mixture from which the bispecific antibody was isolated by using a dual anti-idiotypic purification process. C57BL/6J mice were finally sensitized and challenged to HDM extracts and treated during challenge with the antibodies. RESULTS: We successfully generated and characterized the monospecific and bispecific antibodies targeting IL-4Rα and IL-5. The monospecific antibodies could suppress eosinophilia, IgE synthesis, or both, whereas only the IL-4Rα/IL-5-bispecific antibody and the combination of monospecific antibodies additionally inhibited GCM and BHR. CONCLUSION: Type 2 cytokines act synergistically to cause GCM and BHR in HDM-exposed mice. These preclinical results show the feasibility of generating bispecific antibodies that target multiple cytokine signaling pathways as superior inhibitors of asthma features, including the difficult-to-treat GCM.

Eosinophilic Gastrointestinal Disease.

This JAMA Insights Clinical Update discusses the symptoms, diagnosis, and management of eosinophilic gastrointestinal diseases.