HBV messing with the B-cell genome leads to DLBCL

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Reversion of anergy signatures in clonal CD21low B cells of mixed cryoglobulinemia after clearance of HCV viremia.

Hepatitis C virus (HCV) causes mixed cryoglobulinemia (MC) by driving clonal expansion of IgM+CD27+ B cells. These cells display both the features of anergy induced by continual engagement of the B cell receptor (BCR), such as high expression of phosphorylated extracellular signal regulated kinase (pERK) and reduced lifespan, and of virus-specific exhaustion such as CD21low phenotype and defective response to ligation of BCR and Toll-like receptor 9 (TLR9). Usually MC regresses after eradication of HCV with interferon, whose immunomodulatory activity might contribute to this effect. We investigated phenotypic and functional changes in clonal B cells of MC patients with sustained virologic responses to direct-acting antivirals (DAA), which lack immunomodulatory properties. We found that high pERK expression and accelerated apoptosis revert within 4 weeks after beginning therapy, whereas clonal B cells unresponsive to TLR9 stimulation persist for at least 24 weeks although they may partially rescue normal CD21 expression. Thus, similar to mouse models, features of anergy in MC B cells rapidly revert after disengagement from HCV, whereas virus-specific exhaustion imparts a durable inhibitory imprint on cell function. Treatment of HCV+ MC with DAA provides a valuable tool for untangling the molecular mechanisms of anergy and exhaustion in human B cells

Early benralizumab for eosinophilic myocarditis in eosinophilic granulomatosis with polyangiitis

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Hepatitis C virus- related cryoglobulinemic vasculitis: A review of the role of the new direct antiviral agents (DAAs) therapy

Hepatitis C virus (HCV) infection affects about 70 million people worldwide. HCV is responsible for both hepatitis and extra-hepatic manifestations. Chronic infection has been shown to develop in about 70% of cases and can progress to cirrhosis or hepatocellular carcinoma. Ten percent of HCV patients may develop extra-hepatic manifestations, including mixed cryoglobulinemia (MC) and non-Hodgkin lymphomas. Many studies have demonstrated that, after antiviral therapy, MC can disappear along with HCV eradication. After the introduction of the new direct antiviral agents (DAAs), the combination of pegylated interferon and ribavirin has been abandoned. Several studies on new DAAs have reported remarkable 90% to 100% eradication rates, regardless of HCV genotype. Treatment with DAAs has comparable efficacy on viral eradication in patients with MC, but definite clinical improvements of vasculitis can be observed only in half the patients. On the contrary, the regression of renal disease and lympho-proliferative disorders, induced by HCV, appears to have a lower remission rate after viral eradication with DAAs and most cases need immunosuppressive treatments. In HCV related CV, the main clinical goal must be early eradication of HCV, to avoid organ complication and manifestation of lympho-proliferative diseases. This review focuses on the role of DAAs in treatment of HCV-related cryoglobulinemic vasculitis

Hepatitis B virus-infection related cryoglobulinemic vasculitis. Clinical manifestations and the effect of antiviral therapy: A review of the literature

Objective: Hepatitis B virus (HBV) infection causes chronic hepatitis, cirrhosis, and hepatocellular carcinoma. Furthermore, about 20% of the patients develop extrahepatic manifestations such as cryoglobulinemic vasculitis (CV), polyarteritis nodosa, non-rheumatoid arthritis, glomerulonephritis and non-Hodgkin lymphoma. This review analyzed literature data on clinical manifestations of HBV-related CV and the impact of antiviral therapy with analoques nucleotide. Methods: A PubMed search was performed to select eligible studies in the literature, up to July 2022. Results: Some studies have analyzed clinical manifestations in HBV-related CV and have investigated the role of antiviral therapy with nucleotides analogues (NAs). Clinical manifestations of CV vary from mild to moderate (purpura, asthenia and arthralgias) to severe (leg ulcers, peripheral neuropathy, glomerulonephritis, and non-Hodking lymphoma). NAs therapy leads to suppression of HBV-DNA; therefore, it is capable of producing clinical response in the majority of patients with mild to moderate symptoms. Conclusion: Antiviral therapy with NAs is the first choice for HBV suppression and control of mild to moderate disease. In severe vasculitis (glomerulonephritis, progressive peripheral neuropathy and leg ulcers), rituximab alone or with plasma-exchange is always indicated in combination with antiviral therapy

Effectiveness of Immunoglobulin Replacement Therapy on Clinical Outcome in Patients with Primary Antibody Deficiencies: Results from a Multicenter Prospective Cohort Study

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COVID-19 vaccine immunogenicity in 16 patients with autoimmune systemic diseases. Lack of both humoral and cellular response to booster dose and ongoing disease modifying therapies

Patients with autoimmune systemic diseases (ASDs) represent a frail population during the ongoing COVID-19 pandemic. The vaccination is the major preventive measure; however, a significant number of ASD patients show an impaired production of anti-COVID-19 neutralizing antibodies (NAb), possibly counterbalanced by adequate T-cell response. The present study aimed at evaluating both humoral and cellular response to COVID-19 vaccine booster dose in this particular setting

Distinct platelet crosstalk with adaptive and innate immune cells after adenoviral and mRNA vaccination against SARS-CoV-2

Background: Genetic-based COVID-19 vaccines have proved highly effective in reducing the risk of hospitalization and death. As they were first distributed on a large-scale population, adenoviral-based vaccines were linked to a very rare thrombosis with thrombocytopenia syndrome and the interplay between platelets and vaccinations increasingly gained attention. Objective: To study the crosstalk between platelets and the vaccine-induced immune response. Methods: We prospectively enrolled young healthy volunteers who received the mRNA-based vaccine, BNT162b2 (n=15), or the adenovirus-based vaccine, AZD1222 (n=25) and studied their short-term platelet and immune response before and after vaccine injections. In a separate cohort, we retrospectively analysed the effect of aspirin on the antibody response 1 and 5 months after BNT162b2 vaccination. Results: Here we show that a faster antibody response to either vaccine is associated to the formation of platelet aggregates with marginal zone-like B-cells, a subset geared to bridge the temporal gap between innate and adaptive immunity. However, while the mRNA-based vaccine is associated with a more gradual and tolerogenic response that fosters the crosstalk between platelets and adaptive immunity, the adenovirus-based vaccine, the less immunogenic of the two, evokes an antiviral-like response during which platelets are cleared and less likely to cooperate with B-cells. Moreover, subjects taking aspirin (n=56) display lower antibody levels after BNT162b2 vaccination compared to matched individuals. Conclusions: Platelets are a component of the innate immune pathways that promote the B-cell response after vaccination. Future studies on the platelet-immune crosstalk post-immunization will improve safety, efficacy, and strategic administration of next-generation vaccines

Dual stimulation by autoantigen and CpG fosters the proliferation of exhausted rheumatoid factor-specific CD21low B cells in hepatitis C virus-cured mixed cryoglobulinemia

Hepatitis C virus (HCV) causes mixed cryoglobulinemia (MC) by driving clonal expansion of B cells expressing B cell receptors (BCRs), often encoded by the VH1-69 variable gene, endowed with both rheumatoid factor (RF) and anti-HCV specificity. These cells display an atypical CD21low phenotype and functional exhaustion evidenced by unresponsiveness to BCR and Toll-like receptor 9 (TLR9) stimuli. Although antiviral therapy is effective on MC vasculitis, pathogenic B cell clones persist long thereafter and can cause virus-independent disease relapses. MethodsClonal B cells from patients with HCV-associated type 2 MC or healthy donors were stimulated with CpG or heath-aggregated IgG (as surrogate immune complexes) alone or in combination; proliferation and differentiation were then evaluated by flow cytometry. Phosphorylation of AKT and of the p65 NF-kB subunit were measured by flow cytometry. TLR9 was quantified by qPCR and by intracellular flow cytometry, and MyD88 isoforms were analyzed using RT-PCR. DiscussionWe found that dual triggering with autoantigen and CpG restored the capacity of exhausted VH1-69pos B cells to proliferate. The signaling mechanism for this BCR/TLR9 crosstalk remains elusive, since TLR9 mRNA and protein as well as MyD88 mRNA were normally expressed and CpG-induced phosphorylation of p65 NF-kB was intact in MC clonal B cells, whereas BCR-induced p65 NF-kB phosphorylation was impaired and PI3K/Akt signaling was intact. Our findings indicate that autoantigen and CpG of microbial or cellular origin may unite to foster persistence of pathogenic RF B cells in HCV-cured MC patients. BCR/TLR9 crosstalk might represent a more general mechanism enhancing systemic autoimmunity by the rescue of exhausted autoreactive CD21low B cells