Julien Serrier

Background: Reactions to animal biological fluids are poorly described in veterinary occupational health, despite exposures during obstetrical and surgical procedures. This study aimed to characterize the clinical features and risk determinants of reactions to mammalian amniotic fluid (AF) and blood in veterinarians. Methods: A questionnaire was distributed to veterinarians practicing in France and Belgium. Data collected included demographics, allergic history, types of animal exposure, clinical features of reactions, time of onset of symptoms, use of protective equipment. Results: Among 317 respondents, 46% reported reactions to AF and 16% to blood. These reactions were predominantly cutaneous and often delayed, contrasting with the more frequent respiratory symptoms reported after common animal contact. Most cases were linked to bovine exposure and occurred early in obstetrical practice. A strong association was observed between the onset of parturitions practice and first symptoms. Increased number of parturitions and absence of protective measures were associated with higher risk. Conclusions: Reactions to mammalian AF and blood represent a distinct occupational entity in veterinary medicine. The symptoms could be suggestive of protein contact dermatitis. Early exposure and insufficient protection may contribute to their development, highlighting the need for preventive strategies and validated diagnostic tools.

Background: The European Regulation list on mandatory labelling of foods includes 14 allergenic foods; however, other foods are also frequently implicated in food‐induced anaphylaxis (FIA). Methods: We analysed FIA cases reported to the Allergy Vigilance Network from 2002 to 2023. Allergenic foods involved in ≥ 1% of cases and not included in the list were assessed as emerging food allergens (EFA). We assessed their frequency, severity (Ring classification), recurrence, and potential presence in hidden form to determine which allergens might warrant inclusion on the list. Results: Among 2999 FIA cases (Ring grades 2–4), 413 cases (13.8%) met the selection criteria, divided into eight allergenic foods or food groups: goat's and sheep's milk (GSM, n = 84; 2.8% of the cases), buckwheat ( n = 71; 2.4%), peas and lentil ( n = 55; 1.8%), alpha‐gal ( n = 50; 1.7%), pine nut ( n = 49; 1.6%), kiwi ( n = 44; 1.5%), beehive products ( n = 30; 1.0%), and apple ( n = 30; 1.0%). Severe reactions (Ring grades 3 and 4) were reported with GSM (46.8% and 4.8%, respectively, including two fatalities), buckwheat (46.5% and1.4%), peas‐lentil (20% and 1.8%), alpha‐gal (54% and 8%), and Grade 3 reactions were reported with pine nut in 49%, kiwi 54.5%, beehive products 33.3% and apple 46.7%. Recurrent reactions and hidden exposures were reported with GSM (56% and 15.5%), buckwheat (49.3% and 16.9%), peas‐lentil (7.3% and 9.0%) and pine nut (12.2% and 4.1%). Conclusion: We identified eight foods frequently involved in FIA and not currently listed in the European regulation. Given their frequency, severity, recurrence, and potential for hidden exposure, we propose that four—goat's and sheep's milk, buckwheat, peas‐lentil, and pine nut—be considered for inclusion in the list.

Background: Anti-N-Methyl-d-aspartate receptor (NMDAR) autoimmune encephalitis (NMDAR AE) is an autoimmune disease characterized by severe psychiatric and neurological symptoms. While the pathogenic role of antibodies (Abs) directed against the GluN1 subunit of NMDAR is well described in this disease, the immune mechanisms involved in the generation of the autoimmune B cell response, especially the role of T helper cells, are poorly understood. Previously, we developed a B-cell-mediated mouse model of NMDAR AE by immunization with a GluN1_359–378 peptide that drives a series of symptoms that recapitulate AE such as anxiety behaviour and spatial memory impairment. Results: In this mouse model, we identified anti-GluN1-specific CD4⁺ but also CD8⁺ T cells in both spleen and meninges. T helper cells have a polyfunctional profile, arguing for a T and B cell crosstalk to generate anti-GluN1 pathogenic Abs. Interestingly, proteomic analysis of AE meninges showed enrichment of differentially expressed proteins in biological processes associated with B cell activation and cytokine signalling pathways. Conclusions: This study identified, for the first time, a potential contribution of T helper cells in the pathology of NMDAR AE and paved the way for the development of future tolerogenic approaches to treat relapses.