Background In atopic individuals, food ingestion drives the production of IgE antibodies that can trigger hypersensitivity reactions. The IL-4 pathway plays critical roles in this response and genetic polymorphisms in its components have been linked to allergy. Objective To test whether an activating mutation in the IL-4 receptor (IL-4R) α chain enhances allergic responses to a food antigen. Methods F709 mice, in which the IL-4Rα immuno-tyrosine inhibitory motif (ITIM) motif is inactivated, were gavage fed with ovalbumin (OVA). Reactions to OVA challenge and immune responses including antibody production and Th2 responses were assessed. Results F709 mice, but not wild-type (WT) controls, sensitized by gavage with OVA and either cholera toxin (CT) or Staphylococcal enterotoxin B (SEB), displayed mast cell activation and systemic anaphylaxis upon enteral challenge. Anaphylaxis was elicited even in F709 mice enterally sensitized with OVA alone. Bone marrow chimera experiments established that the increased sensitivity conferred by the F709 genotype was mediated mostly by hematopoietic cells but that nonhematopoietic cells also contributed. F709 mice exhibited increased intestinal permeability to macromolecules. The F709 genotype conferred increased OVA-specific IgE but not IgG1 responses, local and systemic Th2 responses and intestinal mast cell hyperplasia as compared with WT mice. Anaphylaxis was abrogated in F709 mice lacking IgE or the high affinity receptor for IgE (FcεRI). Conclusion Augmented IL-4Rα signaling confers increased intestinal permeability and dramatically enhanced sensitivity to food allergens. Unlike anaphylaxis to injected antigens, which in rodents can be mediated by either IgE or IgG antibodies, the food-induced response in F709 mice is solely IgE-dependent.

Autoimmune diseases, including multiple sclerosis and type 1 diabetes mellitus, affect about 5% of the worldwide population. In the last decade, reports have accumulated on various autoimmune disorders, such as idiopathic thrombocytopenia purpura, myopericarditis, primary ovarian failure, and systemic lupus erythematosus (SLE), following vaccination. In this review, we discuss the possible underlying mechanisms of autoimmune reactions following vaccinations and review cases of autoimmune diseases that have been correlated with vaccination. Molecular mimicry and bystander activation are reported as possible mechanisms by which vaccines can cause autoimmune reactions. The individuals who might be susceptible to develop these reactions could be especially not only those with previous post-vaccination phenomena and those with allergies but also in individuals who are prone to develop autoimmune diseases, such as those with a family history of autoimmunity or with known autoantibodies, and the genetic predisposed individuals.Further research is encouraged into the direct associations between vaccines and autoimmune conditions, and the biological mechanisms behind them.

Acute acalculous cholecystitis (AAC) is the inflammatory disease of the gallbladder in the absence of gallstones. AAC is estimated to represent at least 50% to 70% of all cases of acute cholecystitis during childhood. Although this pathology was originally described in critically ill or post-surgical patients, most pediatric cases have been observed during several infectious diseases. In addition to cases caused by bacterial and parasitic infections, most pediatric reports after 2000 described children developing AAC during viral illnesses (such as Epstein-Barr virus and hepatitis A virus infections). Moreover, some pediatric cases have been associated with several underlying chronic diseases and, in particular, with immune-mediated disorders. Here, we review the epidemiological aspects of pediatric AAC, and we discuss etiology, pathophysiology and clinical management, according to the cases reported in the medical literature.

The awareness of the occurrence of MpEPDs, showing very variable clinical expressions, could promote a correct diagnosis and an appropriate treatment. The knowledge of disease mechanisms in MpEPDs is largely incomplete, but recent advances from clinical studies and murine models might promote and direct future research.