The clinical significance of allergen-specific IgG4 in allergic diseases
IgG4 is a subclass of IgG antibody with a unique molecular feature of (Fragment antigen- binding) Fab-arm exchange, allowing bispecific antigen binding in a mono-valent manner. With low binding affinity to C1q and Fcγreceptors, IgG4 is incapable of forming immune complexes and activating the complem...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2022-10-01
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| Series: | Frontiers in Immunology |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fimmu.2022.1032909/full |
| _version_ | 1828164716942327808 |
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| author | Lu Qin Lan-Fang Tang Lei Cheng Hui-Ying Wang |
| author_facet | Lu Qin Lan-Fang Tang Lei Cheng Hui-Ying Wang |
| author_sort | Lu Qin |
| collection | DOAJ |
| description | IgG4 is a subclass of IgG antibody with a unique molecular feature of (Fragment antigen- binding) Fab-arm exchange, allowing bispecific antigen binding in a mono-valent manner. With low binding affinity to C1q and Fcγreceptors, IgG4 is incapable of forming immune complexes and activating the complement pathway, exhibiting a non-inflammatory feature. IgG4 is produced similarly to IgE and is considered a modified reaction to IgE class-switching response under certain conditions. It could also counteract IgE-activated inflammation. However, the clinical significance of IgG4 in allergic diseases is complex and controversial. Three viewpoints have been suggested to describe the role of IgG4. IgG4 can act as a tolerance–inducer to play a protective role under repeated and rapid incremental dosing of allergen exposure in allergen immunotherapy (AIT), supported by allergies in cat raisers and venom desensitization in beekeepers. Another viewpoint accepted by mainstream specialists and guidelines of Food Allergy and Management in different countries points out that food-specific IgG4 is a bystander in food allergy and should not be used as a diagnostic tool in clinical work. However, eosinophilic esophagitis (EoE) investigation revealed a direct clinical relevance between physiopathology and serum IgG4 in cow milk and wheat. These factors indicate that allergen-specific IgG4 plays a multifaceted role in allergic diseases that is protective or pathogenic depending on different allergens or exposure conditions. |
| first_indexed | 2024-04-12T01:31:11Z |
| format | Article |
| id | doaj.art-cbe43ce777da4f3781e2064c3df0d5bb |
| institution | Directory Open Access Journal |
| issn | 1664-3224 |
| language | English |
| last_indexed | 2024-04-12T01:31:11Z |
| publishDate | 2022-10-01 |
| publisher | Frontiers Media S.A. |
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| series | Frontiers in Immunology |
| spelling | doaj.art-cbe43ce777da4f3781e2064c3df0d5bb2022-12-22T03:53:29ZengFrontiers Media S.A.Frontiers in Immunology1664-32242022-10-011310.3389/fimmu.2022.10329091032909The clinical significance of allergen-specific IgG4 in allergic diseasesLu Qin0Lan-Fang Tang1Lei Cheng2Hui-Ying Wang3Department of Pulmonology, the Children’s Hospital of Zhejiang University School of Medicine, Hangzhou, ChinaDepartment of Pulmonology, the Children’s Hospital of Zhejiang University School of Medicine, Hangzhou, ChinaDepartment of Otorhinolaryngology & Clinical Allergy Center, The First Affiliated Hospital, Nanjing Medical University, Nanjing, ChinaDepartment of Allergy and Clinical Immunology, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, ChinaIgG4 is a subclass of IgG antibody with a unique molecular feature of (Fragment antigen- binding) Fab-arm exchange, allowing bispecific antigen binding in a mono-valent manner. With low binding affinity to C1q and Fcγreceptors, IgG4 is incapable of forming immune complexes and activating the complement pathway, exhibiting a non-inflammatory feature. IgG4 is produced similarly to IgE and is considered a modified reaction to IgE class-switching response under certain conditions. It could also counteract IgE-activated inflammation. However, the clinical significance of IgG4 in allergic diseases is complex and controversial. Three viewpoints have been suggested to describe the role of IgG4. IgG4 can act as a tolerance–inducer to play a protective role under repeated and rapid incremental dosing of allergen exposure in allergen immunotherapy (AIT), supported by allergies in cat raisers and venom desensitization in beekeepers. Another viewpoint accepted by mainstream specialists and guidelines of Food Allergy and Management in different countries points out that food-specific IgG4 is a bystander in food allergy and should not be used as a diagnostic tool in clinical work. However, eosinophilic esophagitis (EoE) investigation revealed a direct clinical relevance between physiopathology and serum IgG4 in cow milk and wheat. These factors indicate that allergen-specific IgG4 plays a multifaceted role in allergic diseases that is protective or pathogenic depending on different allergens or exposure conditions. https://www.frontiersin.org/articles/10.3389/fimmu.2022.1032909/fullIgG4Fab-arm exchangeallergen specific immunotherapyfood allergyeosinophilic esophagitis |
| spellingShingle | Lu Qin Lan-Fang Tang Lei Cheng Hui-Ying Wang The clinical significance of allergen-specific IgG4 in allergic diseases Frontiers in Immunology IgG4 Fab-arm exchange allergen specific immunotherapy food allergy eosinophilic esophagitis |
| title | The clinical significance of allergen-specific IgG4 in allergic diseases |
| title_full | The clinical significance of allergen-specific IgG4 in allergic diseases |
| title_fullStr | The clinical significance of allergen-specific IgG4 in allergic diseases |
| title_full_unstemmed | The clinical significance of allergen-specific IgG4 in allergic diseases |
| title_short | The clinical significance of allergen-specific IgG4 in allergic diseases |
| title_sort | clinical significance of allergen specific igg4 in allergic diseases |
| topic | IgG4 Fab-arm exchange allergen specific immunotherapy food allergy eosinophilic esophagitis |
| url | https://www.frontiersin.org/articles/10.3389/fimmu.2022.1032909/full |
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