Booster Dose of SARS-CoV-2 mRNA Vaccine in Kidney Transplanted Patients Induces Wuhan-Hu-1 Specific Neutralizing Antibodies and T Cell Activation but Lower Response against Omicron Variant.

Kidney transplanted recipients (KTR) are at high risk of severe SARS-CoV-2 infection due to immunosuppressive therapy. Although several studies reported antibody production in KTR after vaccination, data related to immunity to the Omicron (B.1.1.529) variant are sparse. Herein, we analyzed anti-SARS-CoV-2 immune response in seven KTR and eight healthy controls after the second and third dose of the mRNA vaccine (BNT162b2). A significant increase in neutralizing antibody (nAb) titers were detected against pseudoviruses expressing the Wuhan-Hu-1 spike (S) protein after the third dose in both groups, although nAbs in KTR were lower than controls. nAbs against pseudoviruses expressing the Omicron S protein were low in both groups, with no increase after the 3rd dose in KTR. Reactivity of CD4+ T cells after boosting was observed when cells were challenged with Wuhan-Hu-1 S peptides, while Omicron S peptides were less effective in both groups. IFN-γ production was detected in KTR in response to ancestral S peptides, confirming antigen-specific T cell activation. Our study demonstrates that the 3rd mRNA dose induces T cell response against Wuhan-Hu-1 spike peptides in KTR, and an increment in the humoral immunity. Instead, humoral and cellular immunity to Omicron variant immunogenic peptides were low in both KTR and healthy vaccinated subjects.

Peripheral blood immune response elicited by beta-lactoglobulin in childhood cow's milk allergy.

Several studies analyzing the immune responses in patients with cow's milk allergy (CMA) have used T-cell lines or T-cell clones that require prolonged in vitro cell culturing and may result in a switched cell phenotype and function. We investigated immune responses to beta-lactoglobulin (b-LG) in peripheral blood mononuclear cells after a short in vitro antigen stimulation in children with acute CMA (both IgE-mediated and non-IgE-mediated forms) and in those who outgrew an IgE-mediated CMA. Healthy controls were also investigated. Peripheral blood mononuclear cells were assayed for IL-13, IFN-γ, IL-4, and IL-10. Although b-LG induced a cytokine production and/or cell proliferation almost in all children, included healthy controls, differences were observed among the four groups. Children with IgE-mediated CMA had a marked Th2-response, with high IL-13 production and proliferation, but low IFN-γ; by contrast, children with non-IgE-mediated CMA produced no, or very low, IL-13 and cell proliferation. Children, who outgrew CMA, showed a shift to a Th1-response, with reduced IL-13 and increased IFN-γ. IL-10-responses were high in all groups, with the highest level in healthy children; by contrast, IL-4 was undetectable in all children. This study highlights the use of shortly stimulated peripheral blood cells to investigate the food-induced immune responses.

Episodic Angioedema with Hypereosinophilia (Gleich's Syndrome): A Case Report and Extensive Review of the Literature.

Episodic angioedema with eosinophilia (EAE) (Gleich's syndrome) is a rare disease characterized by hypereosinophilia (up to 95 × 109 cells/L), recurrent episodes of angioedema, urticaria, weight gain, and fever, that occur at periodical intervals (usually every 3-4 weeks). The exact etiology of EAE is still unclear, but both eosinophils and abnormalities of cytokines homeostasis seem to play a pivotal role in the pathogenesis of the disease. In particular, the cyclic elevation of serum interleukin-5 before the increase in eosinophil count has been reported. Herein, we performed a broad literature review and report the case of a thirty-two-year-old woman with a two-year history of cyclic angioedema attacks, urticaria, periodic weight gain, and severe hypereosinophilia, diagnosed with EAE and treated with oral corticosteroids. Describing the most relevant clinical features of EAE reported so far in the literature, we aim to provide physicians with some useful tools to help them deal with this disease. In addition, we aim to raise awareness about this rare condition in which approved diagnostic classification criteria are currently missing.

Tocilizumab reduces complement C3 and C4 serum levels in rheumatoid arthritis patients.

Tocilizumab, an anti-interleukin-6 receptor monoclonal antibody, is known to be able to rapidly reduce acute phase reactants. Although complement components are part of the acute phase, no data are available on a possible effect of tocilizumab on complement proteins. Serum levels of complement components C3 and C4 were retrospectively assessed in 19 consecutive rheumatoid arthritis patients eligible for tocilizumab treatment. Tocilizumab was found to reduce all known acute phase reactants, including C3 and C4 levels. C3 and C4 were found to decrease as early as 4 weeks after the first tocilizumab infusion. On average, C3 decreased by 24.02, 27.35, 33.62, and 32.81%, as compared to pre-treatment values, after 1, 3, 6, and 12 months of therapy, respectively; likewise, C4 decreased by 44.74, 43.40, 54.33, and 54.56% at the same time points with respect to pre-treatment values. A discrete proportion of patients (38.46 and 30.76% for C3 and C4, respectively) displayed subnormal complement serum levels early (4 weeks) after initiation of tocilizumab treatment, which raised suspicion for complement consumption. However, no circulating immunocomplexes were found nor did any patient ever display clinical features of immunocomplex disease during a median follow-up of 38 months. After 12 months of therapy, 68.75 and 56.25% of patients had abnormally low C3 and C4 serum levels, respectively. Reduction in C3 and C4 serum levels should be included among the anti-inflammatory effects exerted by tocilizumab and are thus to be considered as an expected outcome of the mechanism of action of this drug.

Uncommon immune-mediated extrahepatic manifestations of HCV infection.

INTRODUCTION: Chronic hepatitis C virus (HCV) infection has been associated with myriad extrahepatic manifestations, often resulting from aberrant immune responses. Among the most common immune-mediated manifestations of HCV infection, mixed cryoglobulinemia is the best known extra-hepatic complication. Areas covered: Here we review less common extrahepatic manifestations of HCV infection, with ascertained or presumed immune pathogenesis and the role of the new all oral direct-acting antiviral agents. Rheumatologic, dermatologic, ophthalmologic, renal, pulmonary, hematologic, cardiovascular, and neuropsychiatric manifestations of HCV infection have been considered. Expert commentary: Pathogenesis of HCV-induced aberrant immune responses resulting in peculiar clinical manifestations is not restricted to a single mechanism. A sound approach would therefore consider implementation of an etiologic treatment, through use of antiviral medications, to stop upstream in the pathogenic process all the immune mechanisms leading to hepatic and extrahepatic abnormalities. With the recent introduction of interferon-free, direct antiviral agents, capable of warranting cure for nearly all HCV-infected patients subjected to therapy, both common and uncommon extrahepatic manifestations of chronic hepatitis C are expected to no longer constitute a matter of comorbidity in the course of HCV infection.

Atrial fibrillation following therapy with high-dose i.v. methylprednisolone: A brief case-based review.

Atrial fibrillation following high-dose i.v. steroids for treatment of severe immune-mediated diseases has been rarely reported in the literature. Here we report a further case of atrial fibrillation following high-dose i.v. methylprednisolone (HDIVMP) therapy of severe thrombocytopenia in a female patient with a flare-up of systemic lupus erythematosus (SLE). The available literature on this topic is reviewed as well.

Repertoire of gluten peptides active in celiac disease patients: perspectives for translational therapeutic applications.

Celiac disease is a common and lifelong food intolerance, affecting approximately 1% of the population. Because of a mechanism not completely understood, the ingestion of wheat gluten, and of homologue proteins of barley and rye, induces in genetically predisposed individuals pronounced inflammatory reactions mainly at the site of small intestine. Gluten, the triggering factor, is a complex protein mixture highly resistant to the gastrointestinal enzymatic proteolysis, and this results in the presence of large, and potentially immunogenic, peptides at the intestinal mucosa surface. During the last decade, several studies have defined gluten peptides able to stimulate adaptive T cells, of either CD4 or CD8 phenotype, and to activate innate (non T) immune cells. This review examines the complete repertoire of gluten peptides recognized by celiac T cells and discusses the several translational implications that the identification of these epitopes opens.