How common are allergic reactions during commercial flights? A systematic review and meta-analysis

Background Global passenger demand for air travel has increased by over 7% annually since 2006, with a strong recovery following the COVID-19 pandemic. Prior to COVID-19, individuals with food allergies reported significant concern and anxiety over the risk of reactions when travelling by air. However, published data of in-flight medical events (IMEs) due to allergic reactions are limited. Objective To undertake a systematic review with meta-analysis to estimate the incidence of in-flight medical emergencies (IMEs) due to allergic reactions on commercial flights. Methods We searched MEDLINE, Embase, PsycINFO, TRANSPORT databases and the Cochrane Register of Controlled Trials for relevant studies reporting IMEs of allergic etiology, published since 1980. Data were extracted in duplicate for meta‐analysis, and risk of bias assessed. Study registration: PROSPERO CRD42022384341. Results 17 studies met the inclusion criteria. At meta-analysis, a pooled estimate of 2.2% (95%CI 1.6%-3.1%) of IMEs are coded as being due to allergic reactions. This may be higher in children (3.1%, 95%CI 1.5%-6.7%). The incidence of allergic IMEs at meta-analysis was 0.7 events per million passengers (95%CI 0.4 to 1.1). Reassuringly, the rate of allergic IMEs has been stable over the past 30 years, despite increasing passenger numbers and food allergy prevalence. Conclusion Allergic reactions coded as IMEs during commercial air travel are uncommon, occurring at an incidence around 10-100 times lower than that reported for accidental allergic reactions to food occurring in the community. Despite increasing passenger numbers and food allergy prevalence, the rate of allergic IMEs has not changed over the past 3 decades

Genes Involved in the Metabolism of Poly-Unsaturated Fatty-Acids (PUFA) and Risk for Crohn's Disease in Children & Young Adults

Epidemiological evidence for the role of polyunsaturated fatty-acids (PUFA) in Crohn's disease (CD) is unclear, although the key metabolite leucotriene B4 (LTB(4)) is closely linked to the inflammatory process. We hypothesized that inherited variation in key PUFA metabolic enzymes may modify susceptibility for CD.A case-control design was implemented at three pediatric gastroenterology clinics in Canada. Children ≤20 yrs diagnosed with CD and controls were recruited. 19 single nucleotide polymorphisms (SNPs) across the ALOX5 (4) CYP4F3 (5) and CYP4F2 (10) genes, were genotyped. Associations between SNPs/haplotypes and CD were examined. A total of 431 cases and 507 controls were studied. The mean (±SD) age of the cases was 12.4 (±3.3) years. Most cases were male (56.4%), had ileo-colonic disease (L3±L4, 52.7%) and inflammatory behavior (B1±p, 87%) at diagnosis. One genotyped CYP4F3 SNP (rs2683037) not in Hardy-Weinberg Equilibrium was excluded. No associations with the remaining 4 CYP4F3 SNPs with CD were evident. However haplotype analysis revealed associations with a two-marker haplotype (TG) (rs3794987 & rs1290617) (p = 0.02; permuted p = 0.08). CYP4F2 SNPs, rs3093158 (OR (recessive) = 0.56, 95% CI = 0.35-0.89; p = 0.01), rs2074902 (OR (trend) = 1.26, 95% CI = 1.00-1.60; p = 0.05), and rs2108622 (OR (recessive) = 1.6, 95% CI = 1.00-2.57; p = 0.05) were significantly associated whereas rs1272 (OR (recessive) = 0.58, 95% CI = 0.30-1.13; p = 0.10) showed suggestions for associations with CD. A haplotype comprising these 4 SNPs was significantly associated (p = 0.007, permuted p = 0.02) with CD. Associations with SNP rs3780901 in the ALOX5 gene were borderline non-significant (OR (dominant) = 1.29, 95% CI = 0.99-1.67; p = 0.056). A haplotype comprising the 4 ALOX5 SNPs (TCAA, p = 0.036) was associated with CD, but did not withstand corrections for multiple comparisons (permuted p = 0.14).Inherited variation in enzymes involved in the synthesis/metabolism of LTB(4) may be associated with CD. These findings implicate PUFA metabolism as a important pathway in the CD pathogenesis

Vaccinations in patients with immune-mediated inflammatory diseases

Patients with immune-mediated inflammatory diseases (IMID) such as RA, IBD or psoriasis, are at increased risk of infection, partially because of the disease itself, but mostly because of treatment with immunomodulatory or immunosuppressive drugs. In spite of their elevated risk for vaccine-preventable disease, vaccination coverage in IMID patients is surprisingly low. This review summarizes current literature data on vaccine safety and efficacy in IMID patients treated with immunosuppressive or immunomodulatory drugs and formulates best-practice recommendations on vaccination in this population. Especially in the current era of biological therapies, including TNF-blocking agents, special consideration should be given to vaccination strategies in IMID patients. Clinical evidence indicates that immunization of IMID patients does not increase clinical or laboratory parameters of disease activity. Live vaccines are contraindicated in immunocompromized individuals, but non-live vaccines can safely be given. Although the reduced quality of the immune response in patients under immunotherapy may have a negative impact on vaccination efficacy in this population, adequate humoral response to vaccination in IMID patients has been demonstrated for hepatitis B, influenza and pneumococcal vaccination. Vaccination status is best checked and updated before the start of immunomodulatory therapy: live vaccines are not contraindicated at that time and inactivated vaccines elicit an optimal immune response in immunocompetent individuals

Nitration of the Pollen Allergen Bet v 1.0101 Enhances the Presentation of Bet v 1-Derived Peptides by HLA-DR on Human Dendritic Cells

Nitration of pollen derived allergens can occur by NO2 and ozone in polluted air and it has already been shown that nitrated major birch (Betula verrucosa) pollen allergen Bet v 1.0101 (Bet v 1) exhibits an increased potency to trigger an immune response. However, the mechanisms by which nitration might contribute to the induction of allergy are still unknown. In this study, we assessed the effect of chemically induced nitration of Bet v 1 on the generation of HLA-DR associated peptides. Human dendritic cells were loaded with unmodified Bet v 1 or nitrated Bet v 1, and the naturally processed HLA-DR associated peptides were subsequently identified by liquid chromatography-mass spectrometry. Nitration of Bet v 1 resulted in enhanced presentation of allergen-derived HLA-DR-associated peptides. Both the copy number of Bet v 1 derived peptides as well as the number of nested clusters was increased. Our study shows that nitration of Bet v 1 alters antigen processing and presentation via HLA-DR, by enhancing both the quality and the quantity of the Bet v 1-specific peptide repertoire. These findings indicate that air pollution can contribute to allergic diseases and might also shed light on the analogous events concerning the nitration of self-proteins

Influenza vaccination for immunocompromised patients: systematic review and meta-analysis from a public health policy perspective.

Immunocompromised patients are vulnerable to severe or complicated influenza infection. Vaccination is widely recommended for this group. This systematic review and meta-analysis assesses influenza vaccination for immunocompromised patients in terms of preventing influenza-like illness and laboratory confirmed influenza, serological response and adverse events

Duodenal hematoma following EGD: comparison with blunt abdominal trauma-induced duodenal hematoma

BACKGROUND: Duodenal hematoma (DH) is a rare complication of esophagogastroduodenoscopy (EGD) with duodenal biopsy and uncommon, but better described following blunt abdominal trauma (BAT). We aimed to describe DH incidence and investigate risk factors for DH development post-EGD and compare its features to those post-BAT. METHODS: Multiple electronic databases were searched for the diagnosis of DH from 2000 to 2012. Inclusion criteria were patients 0 to 21 years of age who developed a DH following EGD with biopsy or BAT. Exclusion criteria were DH secondary to any other mechanism, EGD performed at another medical center, and insufficient information in the electronic medical record to determine treatments or outcomes. RESULTS: A total of 14 post-EGD and 15 post-BAT patients with DH were included in the study. There were 26,905 EGDs with duodenal biopsies performed during the study period, for an incidence of 1:1922 procedures. Thirteen of 14 (93%) post-EGD DH events occurred between 2007 and 2012 (P \u3c 0.001). The proportion of procedures performed under general anesthesia versus moderate sedation, and performed in the supine position versus left lateral decubitus were close to but did not reach statistical significance. DH-related complications and time to hematoma resolution was similar between groups. CONCLUSIONS: In a 13-year study period, 14 patients developed DH after EGD, for an incidence of 1:1922. Method of sedation and supine positioning of the patient during endoscopy warrant further investigation as potential risks. The clinical course and time to recovery with conservative management are similar between patients with EGD and BAT-induced DH