Background: Serological tests are a powerful tool in the monitoring of infectious diseases and the detection of host immunity. However, manufacturers often provide diagnostic accuracy data generated through biased studies and the performance in clinical practice is essentially unclear. Objectives: We aimed to determine the diagnostic accuracy of various serological testing strategies for (a) identification of patients with previous coronavirus disease-2019 (COVID-19) and (b) prediction of neutralizing antibodies against SARS-CoV-2 in real-life clinical settings. Methods: We prospectively included 2’573 consecutive health-care workers and 1’085 inpatients with suspected or possible previous COVID-19 at a Swiss University Hospital. Various serological immunoassays based on different analytical techniques (enzyme-linked immunosorbent assays, ELISA; chemiluminescence immunoassay, CLIA; electrochemiluminescence immunoassay, ECLIA; lateral-flow immunoassay, LFI), epitopes of SARS-CoV-2 (nucleocapsid, N; receptor-binding domain, RBD; extended RBD, RBD+; S1 or S2 domain of the spike [S] protein, S1/S2), and antibody subtypes (IgG, pan-Ig) were conducted. A positive real-time PCR test from a nasopharyngeal swab was defined as previous COVID-19. Neutralization assays with live SARS-CoV-2 were performed in a subgroup of patients to assess neutralization activity (n=201). Results: The sensitivity to detect patients with previous COVID-19 was ≥85% in anti-N ECLIA (86.8%) and anti-S1 ELISA (86.2%). Sensitivity was 84.7% in anti-S1/S2 CLIA, 84.0% in anti-RBD+ LFI, 81.0% in anti-N CLIA, 79.2% in anti-RBD ELISA, and 65.6% in anti-N ELISA. The specificity was 98.4% in anti-N ECLIA, 98.3% in anti-N CLIA, 98.2% in anti-S1 ELISA, 97.7% in anti-N ELISA, 97.6% in anti-S1/S2 CLIA, 97.2% in anti-RBD ELISA, and 96.1% in anti-RBD+ LFI. The sensitivity to detect neutralizing antibodies was ≥85% in anti-S1 ELISA (92.7%), anti-N ECLIA (91.7%), anti-S1/S2 CLIA (90.3%), anti-RBD+ LFI (87.9%), and anti-RBD ELISA (85.8%). Sensitivity was 84.1% in anti-N CLIA, and 66.2% in anti-N ELISA. The specificity was ≥97% in anti-N CLIA (100%), anti-S1/S2 CLIA (97.7%), and anti-RBD+ LFI (97.9%). Specificity was 95.9% in anti-RBD ELISA, 93.0% in anti-N ECLIA, 92% in anti-S1 ELISA, and 65.3% in anti-N ELISA. Diagnostic accuracy measures were consistent among subgroups. Conclusions: The diagnostic accuracy of serological tests for SARS-CoV-2 antibodies varied remarkably in clinical practice, and the sensitivity to identify patients with previous COVID-19 deviated substantially from the manufacturer’s specifications. The data presented here should be considered when using such tests to estimate the infection burden within a specific population and determine the likelihood of protection against re-infection.
Allergen immunotherapy (AIT) has gained a permanent place in the therapeutic arsenal for the patient with allergy. Particularly, substantial evidence has been established for the efficacy of AIT in allergic rhinitis. A hallmark of AIT is it disease modifying effect resulting in persistent benefit after the treatment has been terminated. Both the subcutaneous and sublingual mode of administration appear to be safe. It is, however, a matter of debate whether AIT can be implemented for patients with asthma. EAACI and GINA guidelines recommend sublingual AIT in house dust mite driven asthma. The question however remains whether the different available forms of AIT should be used for allergic asthma in general.
Background: The administration of L-glutamine (Gln) suppresses allergic airway inflammation via the rapid upregulation of MAPK phosphatase (MKP)-1, which functions as a negative regulator of inflammation by deactivating p38 and JNK mitogen-activated protein kinases (MAPKs). However, the role of endogenous Gln remains to be elucidated. Therefore, we investigated the mechanism by which endogenous Gln regulates MKP-1 induction and allergic airway inflammation in an ovalbumin-based murine asthma model. Methods: We depleted endogenous Gln levels using l-γ-glutamyl- p-nitroanilide (GPNA), an inhibitor of the Gln transporter ASCT2, and glutamine synthetase small interfering (si)RNA. Lentivirus expressing MKP-1 was injected to achieve overexpression of MKP-1. Asthmatic phenotypes were assessed using our previously developed ovalbumin-based murine model, which is suitable for examining sequential asthmatic events, including neutrophil infiltration. Gln levels were analyzed using a Gln assay kit. Results: GPNA or glutamine synthetase siRNA successfully depleted endogenous Gln levels. Importantly, homeostatic MKP-1 induction did not occur at all, which resulted in prolonged p38 MAPK and cytosolic phospholipase A 2 (cPLA 2) phosphorylation in Gln-deficient mice. Gln deficiency augmented all examined asthmatic reactions, but it exhibited a strong bias toward increasing the neutrophil count, which was not observed in MKP-1-overexpressing lungs. This neutrophilia was inhibited by a cPLA 2 inhibitor and a leukotriene B4 inhibitor, but not by dexamethasone. Conclusion: Gln deficiency leads to the impairment of MKP-1 induction and activation of p38 MAPK and cPLA 2, resulting in the augmentation of neutrophilic, more so than eosinophilic, airway inflammation.
Background: Nonimmediate (delayed) allergic reactions to penicillins are common and some of them can be life-threatening. The genetic factors influencing these reactions are unknown/poorly known/poorly understood. We assessed the genetic predictors of a delayed penicillin allergy that cover the HLA loci. Methods: Using next-generation sequencing (NGS), we genotyped the MHC region in 24 patients with delayed hypersensitivity compared with 20 patients with documented immediate hypersensitivity to penicillins recruited in Italy. Subsequently, we analyzed in silico Illumina Immunochip genotyping data that covered the HLA loci in 98 Spanish patients with delayed hypersensitivity and 315 with immediate hypersensitivity compared to 1,308 controls. Results: The two alleles DRB3*02:02:01:02 and DRB3*02:02:01:01 were reported in twenty cases with delayed reactions (83%) and ten cases with immediate reactions (50%), but not in the Allele Frequency Net Database. Bearing at least one of the two alleles increased the risk of delayed reactions compared to immediate reactions, with an OR of 8.88 (95% CI, 3.37–23.32; P <0.0001). The haplotype (ACAA) from rs9268835, rs6923504, rs6903608, and rs9268838 genetic variants of the HLA-DRB3 genomic region was significantly associated with an increased risk of delayed hypersensitivity to penicillins (OR, 1.7; 95% CI: 1.06–1.92; P=0.001), but not immediate hypersensitivity. Conclusion: We showed that the HLA-DRB3 locus is strongly associated with an increased risk of delayed penicillin hypersensitivity, at least in Southwestern Europe. The determination of HLA-DRB3*02:02 alleles in the risk management of severe delayed hypersensitivity to penicillins should be evaluated further in larger population samples of different origins.
SARS-CoV-2 caused one of the most devastating pandemics in the recent history of mankind. Due to various countermeasures, including lock-downs, wearing masks and increased hygiene, the virus has been controlled in some parts of the world. More recently, the availability of vaccines, based on RNA or Adenoviruses, have greatly added to our ability to keep the virus at bay, again in some parts of the world only. While available vaccines are effective, it would be desirable to also have more classical vaccines at hand for the future. Key feature of vaccines for long-term control of SARS-CoV-2 would be inexpensive production at large scale, ability to make multiple booster injections and long-term stability at +4 oC. Here we describe such a vaccine candidate, consisting of the SARS-CoV-2 receptor binding motif grafted genetically onto the surface of the immunologically optimized cucumber mosaic virus, called CuMV TT-RBM. Using bacterial fermenter production and continuous flow centrifugation, the productivity of the production process is estimated to be >2.5 million doses per 1000 liter fermenter run and the vaccine candidate is stable for at least 14 months at 4°C. We further demonstrate that the candidate vaccine is highly immunogenic in mice and rabbits and induces more high avidity antibodies compared to convalescent human sera and antibodies induced are more cross-reactive to mutant RBDs for variants of concern (VoC). Furthermore, antibody responses are neutralizing and long-lived. This, the here presented VLP-based vaccine may be a good candidate for use as conventional vaccine in the long-term.
Increased circulating CRTH2+Tregs are associated with asthma control and exacerbation Short running title:Increased circulating CRTH2+Tregs among patients with asthmaTeerapol Chantveerawonga, Sasipa Sangkangjanavanicha,b, Chirawat Chiewchalermsria,c, Panitan Pradubpongsaa, Wat Mitthamsiria, Sarawut Jindaratd, Ming Wange, Mübeccel Akdisf, Milena Sokolowskaf, Cezmi A. Akdisf, Atik Sangasapaviliyaa, Tadech Boonpiyathada,faDivision of Allergy and Clinical Immunology, Department of Medicine, Phramongkutklao Hospital, Bangkok, Thailandb Division of Allergy, Immunology and Rheumatology, Department of Medicine, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, ThailandcDepartment of Medicine, Panyananthaphikkhu Chonprathan Medical Center, Srinakharinwirot University, Nonthaburi, ThailanddDepartment of Pharmacology, Phramongkutklao College of Medicine, Bangkok, ThailandeDepartment of Otolaryngology, Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, and the Beijing Key Laboratory of Nasal Diseases, Beijing Institute of Otolaryngology, Beijing, ChinafSwiss Institute of Allergy and Asthma Research (SIAF), University of Zurich, and the Christine Kühne-Center for Allergy Research and Education (CK-CARE), Davos, Switzerland
COVID-19 vaccination with BNT162b2 and ChAdOx1 vaccines induces nasal neutralizing antibodiesDeclercq Jozefien(1,2,5)*, Tobback Els(3)*, Vanhee Stijn(2,5), Natalie De Ruyck(1), Gerlo Sarah(4), Gevaert Philippe(1)**, Vandekerckhove Linos(3,4)***shared co-first authorship** shared last authorshipUpper Airways Research Lab URL, Department of Otorhinolaryngology, Ghent University, Ghent, BelgiumLaboratory of immunoregulation, VIB Center for Inflammation Research, Ghent, BelgiumDepartment of General Internal Medicine, Ghent University Hospital, Ghent, BelgiumHIV Cure Research Centre, Department of Internal Medicine and Pediatrics, Ghent University, Ghent, BelgiumDepartment of Internal Medicine and Pediatrics, Ghent University, Ghent, BelgiumCorresponding author:Prof. Dr. Philippe GevaertUpper Airways Research Lab URL, Department of Otorhinolaryngology, Ghent University,C Heymanslaan 10, 1P1Ghent, Belgium+3293324922Philippe.email@example.comFinancial support: no fundingWord count: 591
Background Vaccines that incorporate multiple SARS-CoV-2 antigens can further broaden the breadth of virus-specific cellular and humoral immunity. This study describes the development and immunogenicity of SARS-CoV-2 VLP vaccine that incorporates the 4 structural proteins of SARS-CoV-2. Methods VLPs were generated in transiently transfected HEK293 cells, purified by multimodal chromatography and characterized by tunable resistive pulse sensing, AFM, SEM, and TEM. Immunoblotting studies verified the protein identities of VLPs. Cellular and humoral immune responses of immunized animals demonstrated the immune potency of the formulated VLP vaccine. Results Transiently transfected HEK293 cells reproducibly generated vesicular VLPs that were similar in size to and expressing all four structural proteins of SARS-CoV-2. Alum adsorbed, K3-CpG ODN adjuvanted VLPs elicited high titer anti-S, anti-RBD, anti-N IgG, triggered multifunctional Th1 biased T cell responses, reduced virus load and prevented lung pathology upon live virus challenge in vaccinated animals. Conclusion These data suggest that VLPs expressing all four structural protein antigens of SARS-CoV-2 are immunogenic and can protect animals from developing COVID-19 infection following vaccination.
Background: Early exposure to allergens through a defect skin barrier has been proposed as a mechanism for inducing sensitization and development of allergic diseases. We hypothesized that early-onset, severe atopic dermatitis (AD) is associated with development of aeroallergen sensitization and allergic rhinitis. Methods: We included 368 children from the Copenhagen Prospective Studies on Asthma in Childhood 2000 (COPSAC 2000) at-risk mother-child cohort. AD was diagnosed prospectively based on Hanifin&Rajka’s criteria and severity assessed using the Scoring Atopic Dermatitis (SCORAD) index. Early-onset AD was defined as debut ≤1 year, late-onset as debut from 1-6 years. Aeroallergen sensitization and allergic rhinitis were diagnosed at ages 6-7 and 12 years. Associations between early-onset and late-onset AD and allergy endpoints were calculated using general estimating equations (GEE) models to compute the overall odds ratios (OR) for both time points. Results: Early-onset AD (yes/no) and severity (SCORAD) were associated with development of aeroallergen sensitization during childhood; GEE OR=1.68 [1.08; 2.62], p=0.02 and 1.08 [1.03; 1.12], p<0.001, whereas late-onset was not; GEE OR=1.65 [0.92; 2.94], p=0.08 and 1.01 [0.97; 1.06], p=0.55. The same trend was seen for allergic rhinitis with significant association between early-onset AD and allergic rhinitis; GEE OR=1.56 [1.01; 2.41], p=0.04 and severity; GEE OR=1.09 [1.05; 1.13], p<0.001, whereas late-onset AD showed no association. The effects on sensitization and rhinitis of early-onset vs. late-onset AD severity were significantly different: p-interaction sensitization=0.03 and p-interaction rhinitis<0.01. Conclusion: Increasing severity of early-onset AD, but not late-onset AD, associates with aeroallergen sensitization and allergic rhinitis later in childhood.
Role of activation of the coagulation system in the pathogenesis of urticariaTaro Yasuma,1 Corina N. D’Alessandro-Gabazza,1 Tetsu Kobayashi,2 John Morser,3 Esteban C Gabazza.1*1Department of Immunology,2Department of Pulmonary and Critical Care Medicine, Mie University Faculty and Graduate School of Medicine, and Mie University Hospital, Edobashi 2-174, Tsu, Mie 514-8507, Japan.3Division of Hematology, Stanford University School of Medicine, 291 Campus Drive, Stanford, CA 94305, United States*Correspondence: Esteban C Gabazza, MD, PhD, Department of Immunology, Mie University Graduate School of Medicine, Edobashi 2-174, Postal Code 514-8507, Tsu-city, Mie, Japan. Tel.: +81 59 231 5017; fax: +81 59 231 5225.E-mail:firstname.lastname@example.orgWord count: 590
Background The same dosing schedule, 1000 SQ-U times three, with one-month intervals, have been evaluated in most trials of intralymphatic immunotherapy (ILIT) for the treatment of allergic rhinitis (AR). The present studies evaluated if a dose escalation in ILIT can enhance the clinical and immunological effects, without compromising safety. Methods Two randomized double-blind placebo-controlled trials of ILIT for grass pollen induced AR were performed. The first included 29 patients that had recently ended 3 years of SCIT and the second contained 39 not previously vaccinated patients. An up-dosage of 1000-3000-10 000 (5000 + 5000 with 30 minutes apart) SQ-U with one month in between was evaluated. Results Doses up to 10 000 SQ-U was safe after recent SCIT. The combined symptom-medication scores (CSMS) were reduced by 31% and the grass specific IgG4 levels in blood were doubled. In ILIT de novo, the two first patients that received active treatment developed serious adverse reactions at 5000 SQ-U. A modified up-dosing schedule; 1000-3000-3000 SQ-U appeared to be safe but failed to improve the CSMS. Flow cytometry analyses showed increased activation of lymph node derived dendritic but not T-cells. Quality of life and nasal provocation response did not improve in any study. Conclusion ILIT in high doses after SCIT appears to further reduce grass pollen induced seasonal symptoms and may be considered as an add-on treatment for patients that do not reach full symptom control after SCIT. Up-dosing schedules de novo with three monthly injections that exceeds 3 000 SQ-U should be avoided.
This review presents state-of-the-art knowledge and identifies knowledge gaps for future research in the area of exercise-associated modifications of infection susceptibility. Regular moderate-intensity exercise is believed to have beneficial effects on immune health through lowering inflammation intensity and reducing susceptibility to respiratory infections. Infection-promoting consequences are attributed to strenuous exercise as performed by professional athletes. In about half of the athletes presenting respiratory symptoms, no causative pathogen can be identified. Acute bouts of exercise enhance release of proinflammatory mediators thus probably leading to appearance of infection-like respiratory symptoms. Studies assessing influence of regularly repeated exercise on immune response and systemic inflammation are far less numerous than those regarding acute exercise effects. This identifies another knowledge gap requiring further assessment both in recreational and in professional athletes Additionally, ambient and environmental conditions modify systemic inflammatory response and infection susceptibility in particular in outdoor athletes. Both acute and chronic regular exercise influence humoral and cellular immune response mechanisms resulting in decreased specific and non-specific response in competitive athletes. Most promising areas of further research in exercise immunology include: detailed immunological characterization of infection-prone and infection-resistant athletes; efficacy of nutritional and pharmaceutical interventions as countermeasures to infections’ symptoms; and influence of various exercise loads on susceptibility to infections with respiratory viruses, including SARS-CoV-2. Establishing uniform definition of “elite athlete’ shall hopefully allow for comparable and straightforward interpretation of data coming from different studies and settings.