Pediatric Allergy and Immunology最新文献

Background: While the definition of anaphylaxis is clear, its grade of severity remains a subject of debate. The objective of this study was to evaluate the possible discrepancies in the severity scoring system for anaphylaxis in patients with a positive food challenge (OFC), differentiating anaphylactic and non-anaphylactic reactions, using the WHO for the 11th version of the International Classification of Diseases (ICD-11) as the main reference.

Methods: We conducted a retrospective observational study at the University Hospital of Montpellier, France, including patients with a positive food OFC between 2018 and 2022. We classified the severity of each reaction based on 5 different classifications. We also compared patients presenting an anaphylactic versus a non-anaphylactic reaction during the OFC in terms of symptoms and therapeutic approach.

Results: 235 patients presented a positive OFC between January 2018 and December 2022: 143 (60.9%) suffered from anaphylaxis, according to the ICD-11 classification. When comparing the different classifications, a complete concordance was recorded in 8 patients (5.6%) only. All classifications showed a good sensitivity (99.3%-100%), but different specificity (67.4%-93.5%), and discrepancies between them were shown in most patients. Respiratory and gastrointestinal symptoms were significantly more frequent in the anaphylaxis group. Adrenaline was injected in only 47.6% of patients suffering from anaphylaxis, even in a specialized setting.

Conclusion: Our work highlights the need to refine the different scoring systems and, even better, to disseminate unified diagnostic criteria, such as the ICD-11 ones, to avoid the underdiagnosis of anaphylactic reactions and ensure appropriate management for all allergic patients.

Background: Type 2 innate lymphoid cells (ILC2s) are essential for maintaining immune regulation and promoting tissue homeostasis in allergic asthma. How the development of gut microbiota on neonatal ILC2s influences allergic airway inflammation remains unclear. Here we focus on offspring ILC2 development in the context of alterations in maternal gut microbiota.

Methods: C57BL/6 maternal mice were gavaged with OM-85 during pregnancy and/or lactation, ILC2-driven allergic airway inflammation in the OVA-sensitized adult offspring was observed. ILC2 development in offspring early life were investigated using recombinant (r)IL-33, rIL-25 and Bromodeoxyuridine in the vivo experiments. Further ILC2 promoting factors- IL-33 and IL-25 production in offspring early life were analysed. Finally, we examined the changes in gut microbiota and its metabolites in both dams and pups, and explored the effects of short-chain fatty acids (SCFAs) on IL-33 expression and secretion.

Results: Maternal OM-85 administration restrained ILC2-driven allergic airway inflammation in the OVA-sensitized adult offspring. During ILC2 development in offspring early life, maternal OM-85 administration suppressed IL-33 and IL-25 production to inhibit ILC2 expansion and ILC2 responsiveness to alarmins, and infantile ILC2s could persist into adulthood. Maternal OM-85 administration increased SCFAs in breast milk and SCFA-producing gut probiotics (predominant Bacteroides and Blautia) in offspring, especially during pregnancy and lactation. SCFAs down-regulated IL-33 expression and reduced IL-33 secretion by inhibited gasdermin D (GSDMD) formation.

Conclusion: Maternal OM-85 administration restrains ILC2-driven allergic airway inflammation in adult offspring by increasing offspring intestinal SCFAs to modulate ILC2 development at an early stage, demonstrating that the transgenerational effects of maternal OM-85 exposure on offspring innate immunity.

Background: Patients with microdeletion 22q11.2 syndrome (MDS) exhibit immunological defects, characterized by abnormalities in the development of the thymus, which plays a crucial role in T-cell maturation and immune response. As a result, these patients may have impaired adaptive immunity, with decreased responses to vaccination.

Methods: This was a prospective observational study. Vaccine serology (tetanus, diphtheria, Haemophilus influenzae type b for children <5 years, measles, varicella, hepatitis A and B, and SARS-CoV-2) and immune parameters were assessed in MDS patients aged between 1 and 25 years followed in Geneva between February 2022 and April 2023.

Results: 41 MDS patients were included. The median age was 13 years old. Most of them reported recurrent otitis and bronchitis up to 10 years, and a mild COVID-19 disease in the past. Immunological work-up indicated normal immunoglobulin levels and lymphocyte counts for the majority. Most patients were well vaccinated for tetanus, diphtheria, Haemophilus influenzae type b and measles, but only half were fully vaccinated for hepatitis B, and SARS-CoV-2 and only a quarter for hepatitis A. 70% of the patients had received 3 doses of pneumococcal conjugate vaccine in infancy but only a minority an additional dose. While most of them were seroprotected against tetanus, diphtheria, and Hib, a substantial number lacked seroprotection against varicella, measles, hepatitis B, and pneumococcus.

Conclusion: This study suggests that regular assessment of antibody levels for measles, hepatitis B, varicella, and pneumococcus, regardless of vaccination status should be encouraged in MDS patients, with reimmunization according to vaccine serology, to enhance vaccine immunity.