Recent developments in the immunopathology of COVID-19.

There has been an important change in the clinical characteristics and immune profile of Coronavirus disease 2019 (COVID-19) patients during the pandemic thanks to the extensive vaccination programs. Here, we highlight recent studies on COVID-19, from the clinical and immunological characteristics to the protective and risk factors for severity and mortality of COVID-19. The efficacy of the COVID-19 vaccines and potential allergic reactions after administration are also discussed. The occurrence of new variants of concerns such as Omicron BA.2, BA.4, and BA.5 and the global administration of COVID-19 vaccines have changed the clinical scenario of COVID-19. Multisystem inflammatory syndrome in children (MIS-C) may cause severe and heterogeneous disease but with a lower mortality rate. Perturbations in immunity of T cells, B cells, and mast cells, as well as autoantibodies and metabolic reprogramming may contribute to the long-term symptoms of COVID-19. There is conflicting evidence about whether atopic diseases, such as allergic asthma and rhinitis, are associated with a lower susceptibility and better outcomes of COVID-19. At the beginning of pandemic, the European Academy of Allergy and Clinical Immunology (EAACI) developed guidelines that provided timely information for the management of allergic diseases and preventive measures to reduce transmission in the allergic clinics. The global distribution of COVID-19 vaccines and emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with reduced pathogenic potential dramatically decreased the morbidity, severity, and mortality of COVID-19. Nevertheless, breakthrough infection remains a challenge for disease control. Hypersensitivity reactions (HSR) to COVID-19 vaccines are low compared to other vaccines, and these were addressed in EAACI statements that provided indications for the management of allergic reactions, including anaphylaxis to COVID-19 vaccines. We have gained a depth knowledge and experience in the over 2 years since the start of the pandemic, and yet a full eradication of SARS-CoV-2 is not on the horizon. Novel strategies are warranted to prevent severe disease in high-risk groups, the development of MIS-C and long COVID-19.

Evaluation of the Role of IgE Responses to Der p 1 and Der p 2 in Chinese House Dust Mite-Allergic Patients.

BACKGROUND: The role of specific IgE (sIgE) against Der p 1 and Der p 2 in Chinese patients with house dust mite (HDM) allergy has not yet been well investigated. METHODS: One hundred patients were enrolled, based on sensitization and doctor-diagnosed allergy to HDM. Questionnaires were administered to document demographic and clinical characteristics. Serum IgE reactivity to Dermatophagoides pteronyssinus (Dp) extract, Der p 1, Der p 2 and Der p 10 was measured by ImmunoCAP. RESULTS: Almost all patients were sensitized to Der p 1 (95%) and Der p 2 (93%), with both allergens together being largely responsible for the total anti-HDM IgE response. No evidence for a significant role of Der p 10 was found. Overall, IgE responses to HDM and its 2 major allergens were higher in children than in adults in this cross-sectional study. With increasing age, IgE responses to Der p 2 become more important. A positive correlation was observed between the reaction of sIgE against Dp, Der p 1 and Der p 2 and the number of organs (including the eyes, nose, lungs and skin) that were affected in patients. CONCLUSIONS: In China, Der p 1 and Der p 2 are the dominant allergens in patients with HDM allergy. The relative importance of Der p 1 and Der p 2 changes with age, in favor of Der p 2. Overall, sIgE titers were positively associated with the number of organs affected.

Total arch repair for acute type A aortic dissection with 2 modified techniques: open single-branched stent graft placement and reinforcement of the dissected arch vessel stump with stent graft.

BACKGROUND: In total arch replacement for patients with acute type A aortic dissection, anastomoses of the graft to the left subclavian artery and descending aorta are often difficult, and the arch vessel anastomosis is frequently performed at the site of dissection. To make this procedure easier and safer, we developed 2 modified techniques: open single-branched stent graft placement into the left subclavian artery and the descending aorta and reinforcement of the dissected arch vessel stump with a stent graft neointima. The feasibility and initial clinical results of these 2 new techniques are reported. METHODS AND RESULTS: Total arch repair with the 2 new techniques was performed in 26 patients with acute Stanford type A aortic dissection. Most patients had an uneventful postoperative course, and there were no surgical deaths. All implanted stent grafts were fully opened and not kinked, and there was no space or blood flow surrounding any of the stent grafts. The false lumen of the descending thoracic aorta closed with thrombus formation in 22 of 26 patients. Disappearance of the false lumen and recovery of the true lumen was observed in all of the dissected arch vessels. CONCLUSIONS: Open single-branched stent graft placement into the left subclavian artery and the descending aorta and reinforcement of the dissected arch vessel stump with a stent graft neointima are 2 simple and effective techniques that should make total arch repair an easier and safer procedure for acute type A aortic dissection.

IgE-binding potencies of three peach Pru p 1 isoforms.

SCOPE: Pru p 1, the Bet v 1 homologue from peach, has been identified as a clinically relevant allergen. Three isoforms have been described, two in peach fruit (Pru p 1.0101 and Pru p 1.0201) and one in pollen (Pru p 1.0301). The present study aimed to compare their IgE-binding potencies. METHODS AND RESULTS: Three Pru p 1 isoforms were cloned and expressed as soluble proteins with His-tags in Escherichia coli. Protein identity was confirmed by MS, circular dichroism, and RNAse activity. IgE-binding capacity using ELISA and ImmunoCAP was compared. Three Pru p 1 isoforms had quite similar IgE-binding potencies for 60% of the sera, but more than twofold between any two isoforms among 40% of the 47 sera. The mean IgE binding of Pru p 1.0201 was slightly higher than other two isoforms. In a sera pool, homologous ImmunoCAP inhibition was higher than other two heterologous isoforms. Individual serum with diverse IgE values of three isoforms demonstrated the higher IgE inhibition of specific isoform with higher IgE value. CONCLUSION: A similar and variable pattern of IgE recognition was observed among three Pru p 1 isoforms. The two new isoforms can be used as more accurate diagnostic reagents.

Anaphylaxis and generalized urticaria from eating Chinese bayberry fruit.

Chinese bayberry Myrica rubra is a very popular fruit in southeastern China. In spite of its wide consumption, no allergies to this fruit have been reported previously. Here we report on a 40-year-old woman suffering from anaphylaxis to Chinese bayberry fruit. Prick-prick skin tests revealed strong reactions to fresh Chinese bayberry fruits as well as to peach, and weaker reactions to some other fruits including apple, melon, and banana. ImmunoCAP analysis revealed identical titers of specific IgE (4.3 kU(A)/L) to peach extract and its lipid transfer protein (LTP, rPru p 3), which was confirmed by detection of a 9 kD band following immunoblotting. Immunoblot analysis with Chinese bayberry extract gave bands of 22, 45, and 90 kD, but no 9 kD band was recognized. There was also no evidence of LTP recognition for loquat (36 kD) or melon (24 kD). This first report of a severe allergic reaction to Chinese bayberry fruit in a patient with LTP-mediated peach allergy indicates that other as yet unidentified non-pollen related fruit allergens are involved in this new severe fruit allergy.