Ten-year experience of whole lung lavage in pediatric Pulmonary Alveolar Proteinosis.

BACKGROUND: Pulmonary Alveolar Proteinosis (PAP) is extremely rare and can be caused by hereditary dysfunction of the granulocyte macrophage colony-stimulating factor receptor (GM-CSF) receptor, autoantibodies against GM-CSF, or other diseases leading to alveolar macrophage (AM) dysfunction. This leads to protein accumulation in the lung and severe dyspnea and hypoxemia. Whole lung lavage (WLL) is the first line treatment strategy. METHODS: Here, we present data from more than ten years of WLL practice in pediatric PAP. WLL performed by the use of a single lumen or double lumen tube (SLT vs. DLT) were compared for technical features, procedure time, and adverse events. RESULTS: A total of n=57 procedures in six PAP patients between 3.5 and 14.3 years of age were performed. SLT based WLL in smaller children was associated with comparable rates of adverse events but with longer intervention times and postprocedural intensive care treatment when compared to DLT based procedures. DISCUSSION: Our data shows that WLL is feasible even in small children. DLT based WLL seems to be more effective, and our data supports the notion that it should be considered as early as possible in pediatric PAP. CONCLUSION: WLL lavage is possible in small PAP patients but should performed in close interdisciplinary cooperation and with age appropriate protocols.

Single cell RNA sequencing reveals distinct clusters of Irf8-expressing pulmonary conventional dendritic cells.

A single population of interferon-regulatory factor 8 (Irf8)-dependent conventional dendritic cell (cDC type1) is considered to be responsible for both immunogenic and tolerogenic responses depending on the surrounding cytokine milieu. Here, we challenge this concept of an omnipotent single Irf8-dependent cDC1 cluster through analysis of pulmonary cDCs at single cell resolution. We report existence of a pulmonary cDC1 cluster lacking Xcr1 with an immunogenic signature that clearly differs from the Xcr1 positive cDC1 cluster. The Irf8+Batf3+Xcr1- cluster expresses high levels of pro-inflammatory genes associated with antigen presentation, migration and co-stimulation such as Ccr7, Cd74, MHC-II, Ccl5, Il12b and Relb while, the Xcr1+ cDC1 cluster expresses genes corresponding to immune tolerance mechanisms like Clec9a, Pbx1, Cadm1, Btla and Clec12a. In concordance with their pro-inflammatory gene expression profile, the ratio of Xcr1- cDC1s but not Xcr1+cDC1 is increased in the lungs of allergen-treated mice compared to the control group, in which both cDC1 clusters are present in comparable ratios. The existence of two distinct Xcr1+ and Xcr1- cDC1 clusters is furthermore supported by velocity analysis showing markedly different temporal patterns of Xcr1- and Xcr1+cDC1s. In summary, we present evidence for the existence of two different cDC1 clusters with distinct immunogenic profiles in vivo. Our findings have important implications for DC-targeting immunomodulatory therapies.

Pathogen spectra in hospitalised and nonhospitalised children with community-acquired pneumonia.

Background: Paediatric community-acquired pneumonia (CAP) is a leading cause of paediatric morbidity. However, particularly for outpatients with paediatric CAP, data on aetiology and management are scarce. Methods: The prospective pedCAPNETZ study multicentrically enrols children and adolescents with outpatient-treated or hospitalised paediatric CAP in Germany. Blood and respiratory specimens were collected systematically, and comprehensive analyses of pathogen spectra were conducted. Follow-up evaluations were performed until day 90 after enrolment. Results: Between December 2014 and August 2020, we enrolled 486 children with paediatric CAP at eight study sites, 437 (89.9%) of whom had radiographic evidence of paediatric CAP. Median (interquartile range) age was 4.5 (1.6-6.6) years, and 345 (78.9%) children were hospitalised. The most prevalent symptoms at enrolment were cough (91.8%), fever (89.2%) and tachypnoea (62.0%). Outpatients were significantly older, displayed significantly lower C-reactive protein levels and were significantly more likely to be symptom-free at follow-up days 14 and 90. Pathogens were detected in 90.3% of all patients (one or more viral pathogens in 68.1%; one or more bacterial strains in 18.7%; combined bacterial/viral pathogens in 4.1%). Parainfluenza virus and Mycoplasma pneumoniae were significantly more frequent in outpatients. The proportion of patients with antibiotic therapy was comparably high in both groups (92.4% of outpatients versus 86.2% of hospitalised patients). Conclusion: We present first data on paediatric CAP with comprehensive analyses in outpatients and hospitalised cases and demonstrate high detection rates of viral pathogens in both groups. Particularly in young paediatric CAP patients with outpatient care, antibiotic therapy needs to be critically debated.

Comparison of Three Eradication Treatment Protocols for Pseudomonas Aeruginosa in Children and Adolescents with Cystic Fibrosis.

BACKGROUND: Pseudomonas aeruginosa (Pa) continues to affect disease progression in cystic fibrosis (CF). However, the best eradication regimen remains unclear. This work compares three different antibiotic eradication regimens in pediatric CF: an administration according to a standard-operating procedure (SOP) order vs. administration outside of this order (ooSOP). METHODS: This observational study includes all CF patients<18 years who received one of three Pa eradication treatments in the past eight years at our center: 1) inhaled high-dose tobramycin (Hi-TOBI), 2) inhaled colistin+oral ciprofloxacin (COL/Cip), 3) inhaled low-dose tobramycin+4 intravenous 14-day Pa active antibiotic treatments (lo-Tobra/IV). We compared eradication rates of the three treatment regimens performed according to the SOP-based order vs. ooSOP. Logistic regression analysis was performed to identify risk factors for eradication failure. RESULTS: Performed according to SOP order, Hi-TOBI showed the greatest efficacy, followed by lo-Tobra/IV and finally COL/Cip, while ooSOP lo-Tobra/IV was most successful, followed by COL/Cip and Hi-TOBI. Previous Pa-infections and Pa-therapies along with age at CF diagnosis were risk factors for eradication failure. CONCLUSION: Antibiotic treatment in SOP-based pre-defined order leads to significantly better eradication rates than individual modifications of the order of administration. A short course of inhalational high-dose Tobramycin is most successful at the first attempt. Prolonged antibiotic therapy seems to improve eradication after failed initial attempts.

In vitro neutrophil migration is associated with inhaled corticosteroid treatment and serum cytokines in pediatric asthma.

Background: Different asthma phenotypes are driven by molecular endotypes. A Th1-high phenotype is linked to severe, therapy-refractory asthma, subclinical infections and neutrophil inflammation. Previously, we found neutrophil granulocytes (NGs) from asthmatics exhibit decreased chemotaxis towards leukotriene B4 (LTB4), a chemoattractant involved in inflammation response. We hypothesized that this pattern is driven by asthma in general and aggravated in a Th1-high phenotype. Methods: NGs from asthmatic nd healthy children were stimulated with 10 nM LTB4/100 nM N-formylmethionine-leucyl-phenylalanine and neutrophil migration was documented following our prior SiMA (simplified migration assay) workflow, capturing morphologic and dynamic parameters from single-cell tracking in the images. Demographic, clinical and serum cytokine data were determined in the ALLIANCE cohort. Results: A reduced chemotactic response towards LTB4 was confirmed in asthmatic donors regardless of inhaled corticosteroid (ICS) treatment. By contrast, only NGs from ICS-treated asthmatic children migrate similarly to controls with the exception of Th1-high donors, whose NGs presented a reduced and less directed migration towards the chemokines. ICS-treated and Th1-high asthmatic donors present an altered surface receptor profile, which partly correlates with migration. Conclusions: Neutrophil migration in vitro may be affected by ICS-therapy or a Th1-high phenotype. This may be explained by alteration of receptor expression and could be used as a tool to monitor asthma treatment.

Phenotypic spectrum in recessive STING-associated vasculopathy with onset in infancy: Four novel cases and analysis of previously reported cases.

Gain-of-function variants in the stimulator of interferon response cGAMP interactor 1 (STING1) gene cause STING-Associated Vasculopathy with onset in Infancy (SAVI). Previously, only heterozygous and mostly de novo STING1 variants have been reported to cause SAVI. Interestingly, one variant that only leads to SAVI when homozygous, namely c.841C>T p.(Arg281Trp), has recently been described. However, there are no entries in public databases regarding an autosomal recessive pattern of inheritance. Here, we report four additional unrelated SAVI patients carrying c.841C>T in homozygous state. All patients had interstitial lung disease and displayed typical interferon activation patterns. Only one child displayed cutaneous vasculitis, while three other patients presented with a relatively mild SAVI phenotype. Steroid and baricitinib treatment had a mitigating effect on the disease phenotype in two cases, but failed to halt disease progression. Heterozygous c.841C>T carriers in our analysis were healthy and showed normal interferon activation. Literature review identified eight additional cases with autosomal recessive SAVI caused by c.841C>T homozygosity. In summary, we present four novel and eight historic cases of autosomal recessive SAVI. We provide comprehensive clinical data and show treatment regimens and clinical responses. To date, SAVI has been listed as an exclusively autosomal dominant inherited trait in relevant databases. With this report, we aim to raise awareness for autosomal recessive inheritance in this rare, severe disease which may aid in early diagnosis and development of optimized treatment strategies.

Timing of Blood Sample Processing Affects the Transcriptomic and Epigenomic Profiles in CD4+ T-cells of Atopic Subjects.

Optimal pre-analytical conditions for blood sample processing and isolation of selected cell populations for subsequent transcriptomic and epigenomic studies are required to obtain robust and reproducible results. This pilot study was conducted to investigate the potential effects of timing of CD4+ T-cell processing from peripheral blood of atopic and non-atopic adults on their transcriptomic and epigenetic profiles. Two heparinized blood samples were drawn from each of three atopic and three healthy individuals. For each individual, CD4+ T-cells were isolated from the first blood sample within 2 h (immediate) or from the second blood sample after 24 h storage (delayed). RNA sequencing (RNA-Seq) and histone H3K27 acetylation chromatin immunoprecipitation sequencing (ChIP-Seq) analyses were performed. A multiplicity of genes was shown to be differentially expressed in immediately processed CD4+ T-cells from atopic versus healthy subjects. These differences disappeared when comparing delayed processed cells due to a drastic change in expression levels of atopy-related genes in delayed processed CD4+ T-cells from atopic donors. This finding was further validated on the epigenomic level by examining H3K27 acetylation profiles. In contrast, transcriptomic and epigenomic profiles of blood CD4+ T-cells of healthy donors remained rather unaffected. Taken together, for successful transcriptomics and epigenomics studies, detailed standard operation procedures developed on the basis of samples from both healthy and disease conditions are implicitly recommended.

Effects of Pre-Existing Mental Conditions on Fatigue and Psychological Symptoms Post-COVID-19.

BACKGROUND: Patients who are post-COVID-19 will require more treatment soon. Therefore, it is important to understand the root cause of their psychological and somatic conditions. Previous studies showed contradictory results on the influence of pre-existing mental conditions. The present study examines the influence of these pre-existing conditions and their pre-treatment on the severity of post-COVID-19 symptoms. METHODS: This analysis employs questionnaire data from a large study sample in Germany. Overall, 801 participants were included. All participants rated their health status on a scale from 0 to 100. Fatigue, depression, and anxiety were measured using the FAS, PHQ-9, and GAD-7 scales. RESULTS: All pre-pandemic values showed no significant differences between the groups. The current health status was rated similarly by the recovered patients (µ = 80.5 ± 17.0) and the control group (µ = 81.2 ± 18.0) but significantly worse by acutely infected (µ = 59.0 ± 21.5) and post-COVID-19 patients (µ = 54.2 ± 21.1). Fatigue, depression, and anxiety were similar for recovered patients and the control group. By contrast, there were significant differences between the control and the post-COVID-19 groups concerning fatigue (45.9% vs. 93.1%), depression (19.3% vs. 53.8%), and anxiety (19.3% vs. 22.3%). CONCLUSION: Fatigue and psychological conditions of post-COVID-19 patients are not associated with pre-existing conditions.

Healthcare Workers' Perceptions and Medically Approved COVID-19 Infection Risk: Understanding the Mental Health Dimension of the Pandemic. A German Hospital Case Study.

Introduction: This study analyses how healthcare workers (HCWs) perceived risks, protection and preventive measures during the COVID-19 pandemic in relation to medically approved risks and organizational measures. The aim is to explore "blind spots" of pandemic protection and make mental health needs of HCWs visible. Methods: We have chosen an "optimal-case" scenario of a high-income country with a well-resourced hospital sector and low HCW infection rate at the organizational level to explore governance gaps in HCW protection. A German multi-method hospital study at Hannover Medical School served as empirical case; document analysis, expert information and survey data (n = 1,163) were collected as part of a clinical study into SARS-CoV-2 serology testing during the second wave of the pandemic (November 2020-February 2021). Selected survey items included perceptions of risks, protection and preventive measures. Descriptive statistical analysis and regression were undertaken for gender, profession and COVID-19 patient care. Results: The results reveal a low risk of 1% medically approved infections among participants, but a much higher mean personal risk estimate of 15%. The majority (68.4%) expressed "some" to "very strong" fear of acquiring infection at the workplace. Individual protective behavior and compliance with protective workplace measures were estimated as very high. Yet only about half of the respondents felt strongly protected by the employer; 12% even perceived "no" or "little" protection. Gender and contact with COVID-19 patients had no significant effect on the estimations of infection risks and protective workplace behavior, but nursing was correlated with higher levels of personal risk estimations and fear of infection. Conclusions: A strong mismatch between low medically approved risk and personal risk perceptions of HCWs brings stressors and threats into view, that may be preventable through better information, training/education and risk communication and through investment in mental health and inclusion in pandemic preparedness plans.

IgA+ memory B-cells are significantly increased in patients with asthma and small airway dysfunction.

BACKGROUND: Comprehensive studies investigated the role of T-cells in asthma which led to personalised treatment options targeting severe eosinophilic asthma. However, little is known about the contribution of B-cells to this chronic inflammatory disease. In this study we investigated the contribution of various B-cell populations to specific clinical features in asthma. METHODS: In the All Age Asthma Cohort (ALLIANCE), a subgroup of 154 adult asthma patients and 28 healthy controls were included for B-cell characterisation by flow cytometry. Questionnaires, lung function measurements, blood differential counts and allergy testing of participants were analysed together with comprehensive data on B-cells using association studies and multivariate linear models. RESULTS: Patients with severe asthma showed decreased immature B-cell populations while memory B-cells were significantly increased compared with both mild-moderate asthma patients and healthy controls. Furthermore, increased frequencies of IgA+ memory B-cells were associated with impaired lung function and specifically with parameters indicative for augmented resistance in the peripheral airways. Accordingly, asthma patients with small airway dysfunction (SAD) defined by impulse oscillometry showed increased frequencies of IgA+ memory B-cells, particularly in patients with mild-moderate asthma. Additionally, IgA+ memory B-cells significantly correlated with clinical features of SAD such as exacerbations. CONCLUSIONS: With this study we demonstrate for the first time a significant association of increased IgA+ memory B-cells with asthma and SAD, pointing towards future options for B-cell-directed strategies in preventing and treating asthma.

IRIS: Infection with RespIratory Syncytial Virus in infants-a prospective observational cohort study.

BACKGROUND: Respiratory syncytial virus (RSV) is the most common cause of acute lower respiratory tract infection in infants. Globally, RSV is responsible for approximately 3.2 million hospital admissions and about 60,000 in-hospital deaths per year. METHODS: Infection with RespIratory Syncytial Virus (IRIS) is an observational, multi-centre study enrolling infants with severe RSV infection and healthy controls. Inclusion criteria are age between 0 and 36 months and hospitalisation due to RSV infection at three German sites. Exclusion criteria are premature birth, congenital or acquired bronchopulmonary or cardiac diseases, and immunodeficiency. Healthy control probands are enrolled via recruitment of patients undergoing routine surgical procedures. Blood and respiratory specimens are collected upon admission, and RSV and other pathogens are analysed by multiplex polymerase chain reaction. Different biomaterials, including plasma, nasal lining fluid, blood cells, DNA, and RNA specimens, are sampled in a dedicated biobank. Detailed information on demographic characteristics and medical history is recorded, and comprehensive clinical data, including vital signs, medication, and interventions. DISCUSSION: The IRIS study aims to discover host and viral factors controlling RSV disease courses in infants. The approach including multi-omics characterisation in clinically well-characterized children with RSV bronchiolitis seeks to improve our understanding of the immune response against this virus. It may disclose novel diagnostic and treatment approaches for respiratory infections in infants. TRIAL REGISTRATION: ClinicalTrials.gov, NCT04925310. Registered 01 October 2021-Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT04925310?cond=NCT04925310&draw=2&rank=1.

Pulmonary Alveolar Microlithiasis: A novel patient and brief review of the literature.

Pulmonary Alveolar Microlithiasis (PAM) is a rare hereditary lung disease caused by biallelic pathogenic variants (pV) in the solute family 34 member 2 gene (SLC34A2; Izumi et al., Am J Respir Crit Care Med 2007; 175: 263-268). pVs in this sodium phosphate co-transporter gene lead to accumulation of calcium phosphate crystals within pulmonary alveoli. More than 1000 cases of PAM were thus far reported, with high variance in disease courses (Stamatis et al., Ann Thorac Surg 1993; 56: 972-975). Frequently, asymptomatic cases are observed, and often times slow disease progression until respiratory insufficiency in middle age occurs (Kosciuk, Eur Respir Rev 2020; 29: 200024). Treatment options for PAM are scarce and largely ineffective, and lung transplantation is the only effective therapy in end-stage disease (Stamatis et al., Ann Thorac Surg 1993; 56: 972-975). Here, we report a novel PAM case in an adolescent migrant from East Africa and discuss current diagnostic and therapeutic options.

T2-high asthma phenotypes across lifespan.

RATIONALE: In adults, personalised asthma treatment targets patients with type 2 (T2)-high and eosinophilic asthma phenotypes. It is unclear whether such classification is achievable in children. OBJECTIVES: To define T2-high asthma with easily accessible biomarkers and compare resulting phenotypes across all ages. METHODS: In the multicentre clinical All Age Asthma Cohort (ALLIANCE), 1125 participants (n=776 asthmatics, n=349 controls) were recruited and followed for 2 years (1 year in adults). Extensive clinical characterisation (questionnaires, blood differential count, allergy testing, lung function and sputum induction (in adults)) was performed at baseline and follow-ups. Interleukin (IL)-4, IL-5 and IL-13 were measured after stimulation of whole blood with lipopolysaccharide (LPS) or anti-CD3/CD28. MEASUREMENTS AND MAIN RESULTS: Based on blood eosinophil counts and allergen-specific serum IgE antibodies, patients were categorised into four mutually exclusive phenotypes: "atopy-only", "eosinophils-only", "T2-high" (eosinophilia + atopy) and "T2-low" (neither eosinophilia nor atopy). The T2-high phenotype was found across all ages, even in very young children in whom it persisted to a large degree even after 2 years of follow-up. T2-high asthma in adults was associated with childhood onset, suggesting early origins of this asthma phenotype. In both children and adults, the T2-high phenotype was characterised by excessive production of specific IgE to allergens (p<0.0001) and, from school age onwards, by increased production of IL-5 after anti-CD3/CD28 stimulation of whole blood. CONCLUSIONS: Using easily accessible biomarkers, patients with T2-high asthma can be identified across all ages delineating a distinct phenotype. These patients may benefit from therapy with biologicals even at a younger age.

The First 4 Years - Outcome of Children Identified by Newborn Screening for CF in Germany.

BACKGROUND: Newborn screening (NBS) has been shown to improve cystic fibrosis (CF) disease course and has been widely implemented worldwide. This monocentric study compared children diagnosed by NBS vs. a cohort preceding the implementation of NBS in Germany in 2016 to evaluate ascribed benefits of NBS. METHODS: We compared all children with confirmed CF diagnosis (n=19, "NBS group") out of all children presenting with positive NBS at our center after implementation of NBS (n=100) to children diagnosed with CF at our center within 4 years before NBS implementation (n=29, "pre-NBS group") for outcomes of anthropometry, gastrointestinal and pulmonary disease manifestations and respiratory microbiology. RESULTS: Children diagnosed by NBS had a lower incidence of initial difficulty to thrive (15 vs. 41%) and showed higher mean z-scores for Body-Mass-Index (BMI), weight and length at diagnosis and during study period. Children in the pre-NBS group displayed higher proportions of oxygen-dependent pulmonary exacerbations (10 vs. 0%). They show a significantly lower amount of normal bacterial flora (p=0.005) along with a significantly higher number of throat swab cultures positive for Pseudomonas aeruginosa (p=0.0154) in the first year of life. Yet, pulmonary imaging did not reveal less pulmonary morbidity in the NBS group. CONCLUSIONS: Our results confirm that NBS for CF leads to earlier diagnosis and improves nutritional outcomes in early childhood. Although trajectories of structural lung damage at early age were unaffected by NBS, NBS positive CF patients at preschool age displayed less pulmonary exacerbations and pathological bacteria in throat swabs.

[Care of rheumatology patients during the lockdown in early 2020 : Telemedicine, delegation, patient satisfaction and vaccination behavior]. / Versorgung von rheumatologischen Patienten während des Lockdowns im Frühjahr 2020 : Telemedizin, Delegation, Patientenzufriedenheit und Impfverhalten.

BACKGROUND: Telemedicine was implemented in outpatient care during the lockdown between March and May 2020. The aim of the study was to assess patients from a private practice and the university outpatient department with respect to patient satisfaction with telemedicine, COVID-19 worries and vaccination behavior and to compare the teleconsultation by a medical assistant for rheumatology (RFA) and a physician. METHODS: Patients with rheumatoid arthritis, psoriatric arthropathy or spondylarthritis without treatment modifications since the previous presentation were offered a telemedical replacement appointment within the framework of this study in the case of appointment cancellation by the treating center. Participants were randomized to a telemedicine appointment by a physician or an RFA (RFA university only). The patient history was carried out by telephone and standardized using a questionnaire. The disease activity was determined using the modified clinical disease activity score (CDAI) and the BASDAI. Subsequently, all patients received a pseudonymized evaluation questionnaire. RESULTS: In total 112/116 (96%) patients participated. Of these 88/112 (79%) returned the questionnaire. The RFAs conducted 19/112 (17%) of the telephone calls. The treatment was modified in 19/112 (17%) patients. Concerns about contracting COVID-19 correlated with high disease activity (p = 0.031) including the presence of painful joints (p = 0.001) and high pain levels (VAS ≥7, p = 0.009). These patients would have also cancelled their appointment themselves (p = 0.015). Patient satisfaction with the consultation was good (mean 4.3/5.0 modified FAPI) independent of the institution, the duration of the consultation and the consultation partner. Patients with a high pain intensity were the least satisfied (p = 0.036). Only 42/100 (38.2%) of the patients had been vaccinated against pneumococci and 59/100 (53.6%) against influenza. CONCLUSION: Telemedical care within the framework of a telephone consultation is well-suited for selected patients. With respect to patient satisfaction the delegation of a telemedical consultation to an RFA is possible. There is a need for improvement with respect to the vaccination behavior.

Acute respiratory infections in an adult refugee population: an observational study.

The presence of acute infectious respiratory diseases (ARD) is one of the main reasons why recently arrived refugees seek medical help. This paper investigates the incidence rates of acute respiratory diseases in an adult refugee population as well as associated sociodemographic factors and drug treatments. We conducted a retrospective observational study of deidentified medical records. The data were collected between 2015 and 2019 in the health care centers of two large German initial reception centers for refugees. Multivariable analyses controlling for sociodemographics were carried out using generalized estimating equations. Out of 10,431 eligible residents, 6965 medical encounters of 2840 adult patients were recorded over 30 months. Of all the adult patients, 34.4% sought medical help for a respiratory symptom or diagnosis at least once. Older patients and patients from Sub-Saharan Africa sought help less often. The occurrence of ARD showed a typical distribution over the course of the year. Facility occupancy was not associated with ARD occurrence. Acute respiratory symptoms are a leading cause for adult refugee patients to seek medical care. The doctor contact rates due to ARD were consistently two to three times higher among refugees than among German residents.

COL4A3 is degraded in allergic asthma and degradation predicts response to anti-IgE therapy.

BACKGROUND: Asthma is a heterogeneous syndrome substantiating the urgent requirement for endotype-specific biomarkers. Dysbalance of fibrosis and fibrolysis in asthmatic lung tissue leads to reduced levels of the inflammation-protective collagen 4 (COL4A3). OBJECTIVE: To delineate the degradation of COL4A3 in allergic airway inflammation and evaluate the resultant product as a biomarker for anti-IgE therapy response. METHODS: The serological COL4A3 degradation marker C4Ma3 (Nordic Bioscience, Denmark) and serum cytokines were measured in the ALLIANCE cohort (paediatric cases/controls: n=134/n=35; adult cases/controls: n=149/n=31). Exacerbation of allergic airway disease in mice was induced by sensitising to ovalbumin (OVA), challenge with OVA aerosol and instillation of poly(cytidylic-inosinic). Fulacimstat (chymase inhibitor; Bayer) was used to determine the role of mast cell chymase in COL4A3 degradation. Patients with cystic fibrosis (n=14) and cystic fibrosis with allergic bronchopulmonary aspergillosis (ABPA; n=9) as well as patients with severe allergic uncontrolled asthma (n=19) were tested for COL4A3 degradation. Omalizumab (anti-IgE) treatment was assessed using the Asthma Control Test. RESULTS: Serum levels of C4Ma3 were increased in asthma in adults and children alike and linked to a more severe, exacerbating allergic asthma phenotype. In an experimental asthma mouse model, C4Ma3 was dependent on mast cell chymase. Serum C4Ma3 was significantly elevated in cystic fibrosis plus ABPA and at baseline predicted the success of the anti-IgE therapy in allergic, uncontrolled asthmatics (diagnostic OR 31.5). CONCLUSION: C4Ma3 levels depend on lung mast cell chymase and are increased in a severe, exacerbating allergic asthma phenotype. C4Ma3 may serve as a novel biomarker to predict anti-IgE therapy response.

Humoral and Cellular Immune Responses Against Severe Acute Respiratory Syndrome Coronavirus 2 Variants and Human Coronaviruses After Single BNT162b2 Vaccination.

BACKGROUND: Vaccine-induced neutralizing antibodies are key in combating the coronavirus disease 2019 (COVID-19) pandemic. However, delays of boost immunization due to limited availability of vaccines may leave individuals vulnerable to infection and prolonged or severe disease courses. The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC)-B.1.1.7 (United Kingdom), B.1.351 (South Africa), and P.1 (Brazil)-may exacerbate this issue, as the latter two are able to evade control by antibodies. METHODS: We assessed humoral and T-cell responses against SARS-CoV-2 wild-type (WT), VOC, and endemic human coronaviruses (hCoVs) that were induced after single and double vaccination with BNT162b2. RESULTS: Despite readily detectable immunoglobulin G (IgG) against the receptor-binding domain of the SARS-CoV-2 S protein at day 14 after a single vaccination, inhibition of SARS-CoV-2 S-driven host cell entry was weak and particularly low for the B.1.351 variant. Frequencies of SARS-CoV-2 WT and VOC-specific T cells were low in many vaccinees after application of a single dose and influenced by immunity against endemic hCoV. The second vaccination significantly boosted T-cell frequencies reactive for WT and B.1.1.7 and B.1.351 variants. CONCLUSIONS: These results call into question whether neutralizing antibodies significantly contribute to protection against COVID-19 upon single vaccination and suggest that cellular immunity is central for the early defenses against COVID-19.