The clinical significance of allergen-specific IgG4 in allergic diseases

Single-cell RNA sequencing reveals the landscape of biomarker in allergic rhinitis patient undergoing intracervical lymphatic immunotherapy and related pan-cancer analysis

INTRODUCTION

Allergic rhinitis (AR) is one of the leading allergic diseases worldwide. Allergen immunotherapy (AIT) induces persistent specific allergen tolerance to achieve remission of the symptoms in AR patients. We creatively conducted the intra-cervical lymphatic immunotherapy (ICLIT) for AR patients. However, the underlying molecular mechanism of immune cell response of AIT in AR remains elusive.

METHOD

To investigate the transcriptome profile in AR patients who underwent ICLIT, we comprehensively investigated the transcriptional changes in B cells from peripheral blood mononuclear cells of AR patient by single-cell RNA sequencing. Immunoglobulins and relative key gene, which influences the B cell differentiation, was demonstrated. The biomarkers' association with different types of tumors was investigated.

RESULTS

Naive B cells, germinal center B cells, activated memory B cells, and memory B cells constituted the B cells subsets. The expression of IGHE, IGHGs, IGHA, IGHD, and IGHM from memory B cells was validated. Pseudotime analysis further indicated the dynamic change from the expression of the immunoglobulins in the memory B cells, suggesting that ITGB1 may contribute to the differentiation procedure of memory B cells. The cell-cell communication among these immune cells demonstrated the significantly enhanced CD23, BTLA signaling after ICLIT in AR patient. ITGB1 was upregulated in 13 tumors and downregulated in six others. High ITGB1 expression was linked to poor prognosis in eight types of tumors. ITGB1 expression showed correlations with tumor mutation burden, tissue purity, and microsatellite instability in different types of tumors.

DISCUSSION

ITGB1 was demonstrated as a potential biomarker for AR patients after ICLIT and is significant in identifying immune infiltration in tumor tissue and predicting tumor prognosis.

Pathophysiology of Non-Esophageal Eosinophilic Gastrointestinal Disorders

Eosinophilic gastrointestinal disorder (EGID) is an umbrella term encompassing a group of chronic, immune-mediated disorders characterized by eosinophil-rich inflammation affecting one or more segments of the gastrointestinal tract. A recent consensus in nomenclature and emerging data made possible through multi-center consortia are beginning to unravel the molecular and cellular underpinnings of EGIDs below the esophagus. These emerging findings are revealing both overarching commonalities related to a food allergen-driven, chronic, Th2-mediated immune response as well as location-specific nuances in the pathophysiology of the collective EGIDs. Altogether, these advances offer promise for improved diagnoses and more efficacious interventional strategies.

The top 100 most cited articles in the past 30 years of wheat allergy: a bibliometric analysis

Background

Wheat allergy (WA), characterized by immunological responses to wheat proteins, is a gluten-related disorder that has become increasingly recognized in recent years. Bibliometrics involves the quantitative assessment of publications within a specific academic domain.

Objectives

We aimed to execute an extensive bibliometric study, focusing on the past 30 years of literature related to wheat allergy.

Methods

We searched the Web of Science database on 5th Dec 2023. We used the keywords "wheat allergy or wheat anaphylaxis or wheat hypersensitivity," "gliadin allergy or gliadin anaphylaxis or gliadin hypersensitivity," "wheat-dependent exercise-induced anaphylaxis," and "baker's asthma" for our search. All items published between 1993 and 2023 were included. The top 100 most cited articles were identified and analyzed.

Results

Our study conducted an in-depth bibliometric analysis of the 100 most-cited articles in the field of wheat allergy, published between 2002 and 2019. These articles originated from 20 different countries, predominantly Japan and Germany. The majority of these articles were centered on the pathogenesis and treatment of wheat allergy (WA). The Journal of Allergy and Clinical Immunology (JACI) was the most prolific contributor to this list, publishing 14 articles. The article with the highest citation count was published by Biomed Central (BMC) and garnered 748 citations. The peak citation year was 2015, with a total of 774 citations, while the years 1998, 2001, and 2005 saw the highest publication frequency, each with 7 articles.

Conclusion

Our study aims to provide physicians and researchers with a historical perspective for the scientific progress of wheat allergy, and help clinicians effectively obtain useful articles that have a significant impact on the field of wheat allergy.

IgG4 autoantibodies and autoantigens in the context of IgG4-autoimmune disease and IgG4-related disease

Immunoglobulins are an essential part of the humoral immune response. IgG4 antibodies are the least prevalent subclass and have unique structural and functional properties. In this review, we discuss IgG4 class switch and B cell production. We review the importance of IgG4 antibodies in the context of allergic responses, helminth infections and malignancy. We discuss their anti-inflammatory and tolerogenic effects in allergen-specific immunotherapy, and ability to evade the immune system in parasitic infection and tumour cells. We then focus on the role of IgG4 autoantibodies and autoantigens in IgG4-autoimmune diseases and IgG4-related disease, highlighting important parallels and differences between them. In IgG4-autoimmune diseases, pathogenesis is based on a direct role of IgG4 antibodies binding to self-antigens and disturbing homeostasis. In IgG4-related disease, where affected organs are infiltrated with IgG4-expressing plasma cells, IgG4 antibodies may also directly target a number of self-antigens or be overexpressed as an epiphenomenon of the disease. These antigen-driven processes require critical T and B cell interaction. Lastly, we explore the current gaps in our knowledge and how these may be addressed.

Successful Allergen-Specific Immunotherapy: Induction of Unresponsiveness by 'Vaccination'

The mechanisms of action of allergen-specific immunotherapy (AIT) are often referred to as the induction of 'tolerance'. However, immunological 'tolerance' is defined as an alteration in the function or composition of immune cells. For AIT, this is not always the case, because it can also induce allergen-specific IgG antibodies that block allergic responses. To include all possible mechanisms that may mediate successful AIT, it is advantageous to use the scientific term 'unresponsiveness' instead of 'tolerance'. In praxis, the term 'vaccination' is also appropriate, as AIT medications are specialized vaccines.

Nomenclature of allergic diseases and hypersensitivity reactions: Adapted to modern needs: An EAACI position paper

The exponential growth of precision diagnostic tools, including omic technologies, molecular diagnostics, sophisticated genetic and epigenetic editing, imaging and nano-technologies and patient access to extensive health care, has resulted in vast amounts of unbiased data enabling in-depth disease characterization. New disease endotypes have been identified for various allergic diseases and triggered the gradual transition from a disease description focused on symptoms to identifying biomarkers and intricate pathogenetic and metabolic pathways. Consequently, the current disease taxonomy has to be revised for better categorization. This European Academy of Allergy and Clinical Immunology Position Paper responds to this challenge and provides a modern nomenclature for allergic diseases, which respects the earlier classifications back to the early 20th century. Hypersensitivity reactions originally described by Gell and Coombs have been extended into nine different types comprising antibody- (I-III), cell-mediated (IVa-c), tissue-driven mechanisms (V-VI) and direct response to chemicals (VII). Types I-III are linked to classical and newly described clinical conditions. Type IVa-c are specified and detailed according to the current understanding of T1, T2 and T3 responses. Types V-VI involve epithelial barrier defects and metabolic-induced immune dysregulation, while direct cellular and inflammatory responses to chemicals are covered in type VII. It is notable that several combinations of mixed types may appear in the clinical setting. The clinical relevance of the current approach for allergy practice will be conferred in another article that will follow this year, aiming at showing the relevance in clinical practice where various endotypes can overlap and evolve over the lifetime.

Update on In Vitro Diagnostic Tools and Treatments for Food Allergies

Food allergy (FA) is an adverse immunological reaction to a specific food that can trigger a wide range of symptoms from mild to life-threatening. This adverse reaction is caused by different immunological mechanisms, such as IgE-mediated, non-IgE-mediated and mixed IgE-mediated reactions. Its epidemiology has had a significant increase in the last decade, more so in developed countries. It is estimated that approximately 2 to 10% of the world's population has FA and this number appears to be increasing and also affecting more children. The diagnosis can be complex and requires the combination of different tests to establish an accurate diagnosis. However, the treatment of FA is based on avoiding the intake of the specific allergenic food, thus being very difficult at times and also controlling the symptoms in case of accidental exposure. Currently, there are other immunomodulatory treatments such as specific allergen immunotherapy or more innovative treatments that can induce a tolerance response. It is important to mention that research in this field is ongoing and clinical trials are underway to assess the safety and efficacy of these different immunotherapy approaches, new treatment pathways are being used to target and promote the tolerance response. In this review, we describe the new in vitro diagnostic tools and therapeutic treatments to show the latest advances in FA management. We conclude that although significant advances have been made to improve therapies and diagnostic tools for FA, there is an urgent need to standardize both so that, in their totality, they help to improve the management of FA.