B-cell activating factor (BAFF), BAFF promoter and BAFF receptor allelic variants in hepatitis C virus related Cryoglobulinemic Vasculitis and Non-Hodgkin's Lymphoma

Association of B-cell activating factor gene variants with serum anti-JCV antibody positivity in male patients with multiple sclerosis under natalizumab treatment: Implications for progressive multifocal leukoencephalopathy risk stratification

INTRODUCTION

Progressive multifocal leukoencephalopathy (PML) is a potentially life-threatening complication among Multiple Sclerosis (MS) patients under natalizumab treatment, with serum anti-JCV antibody titers being used for stratification risk. Given the critical role of interferon (IFN)/B-cell activating factor (BAFF) axis in humoral immune responses against viruses, we explored whether it is involved in the generation of serum anti-JCV antibodies among these patients.

METHODS

162 consecutive patients with relapsing-remitting MS under natalizumab treatment were included. Serum anti-JCV antibodies were measured at baseline, as well as 12 and 24 months after treatment initiation. Type I and II IFN-inducible genes and BAFF expression were quantitated in peripheral blood by qRT-PCR. Moreover, BAFF rs9514828, rs1041569, and rs9514827 gene variants were assessed by RFLP-PCR.

RESULTS

While type I and II IFN inducible gene expression were not associated with anti-JCV serum titers, the latter were significantly correlated with BAFF gene expression. Of interest, the TTT haplotype of the studied BAFF variants was more frequently detected in male, but not female anti-JCV (+) MS patients compared to anti-JCV (-) counterparts at baseline, as well as at 12 months and 24 months of natalizumab treatment. Measures of clinical validity/utility for the BAFF TTT haplotype showed 88% specificity, 45%, positive predictive value, and sensitivity of 70% for the discrimination of anti-JCV (+) male MS patients after 24 months of treatment.

CONCLUSIONS

Our study suggests an implication of the BAFF axis in the production of serum anti-JCV antibodies. Additionally, the BAFF TTT haplotype derived from the rs9514828, rs1041569, and rs9514827 variants may represent a novel risk factor for anti-JCV seropositivity and indirectly for PML development among male MS patients treated with natalizumab.

A comparative study of different antiviral treatment protocols in HCV related cryoglobulinemic vasculitis

The treatment of HCV and its sequelae are used to be predominantly based on Interferon (IFN). However, this was associated with significant adverse events as a result of its immunostimulant capabilities. Since their introduction, the directly acting antiviral drugs (DAAs), have become the standard of care to treat of HCV and its complications including mixed cryoglobulinemic vasculitis (MCV). In spite of achieving sustained viral response (SVR), there appeared many reports describing unwelcome complications such as hepatocellular and hematological malignancies as well as relapses. Prolonged inflammation induced by a multitude of factors, can lead to DNA damage and affects BAFF and APRIL, which serve as markers of B-cell proliferation. We compared, head-to-head, three antiviral protocols for HCV-MCV treatment As regards the treatment response and relapse, levels of BAFF and APRIL among pegylated interferon α-based and free regimens (Sofosbuvir + Ribavirin; SOF-RIBA, Sofosbuvir + Daclatasvir; SOF-DACLA). Regarding clinical response HCV-MCV and SVR; no significant differences could be identified among the 3 different treatment protocols, and this was also independent form using IFN. We found no significant differences between IFN-based and free regimens DNA damage, markers of DNA repair, or levels of BAFF and APRIL. However, individualized drug-to-drug comparisons showed many differences. Those who were treated with IFN-based protocol showed decreased levels of DNA damage, while the other two IFN-free groups showed increased DNA damage, being the worst in SOF-DACLA group. There were increased levels of BAFF through follow-up periods in the 3 protocols being the best in SOF-DACLA group (decreased at 24 weeks). In SOF-RIBA, CGs relapsed significantly during the follow-up period. None of our patients who were treated with IFN-based protocol had significant clinico-laboratory relapse. Those who received IFN-free DAAs showed a statistically significant relapse of constitutional manifestations. Our findings suggest that IFN-based protocols are effective in treating HCV-MCV similar to IFN-free protocols. They showed lower levels of DNA damage and repair. We believe that our findings may offer an explanation for the process of lymphoproliferation, occurrence of malignancies, and relapses by shedding light on such possible mechanisms.

Cryoglobulinemic vasculitis: a 2023 update

PURPOSE OF REVIEW

Cryoglobulinemic vasculitis (CV) is an immune complex mediated small vessel vasculitis characterized by the presence of cryoglobulins in serum, often associated with hepatitis C infection, systemic autoimmune diseases or hematological conditions. The focus of this review is to provide an update on new insights into pathogenesis, epidemiology and therapies of infectious and noninfectious type II and type III CV.

RECENT FINDINGS

The introduction of new antiviral drugs for treatment of hepatitis C infection implied major changes in HCV-related CV, allowing to shed new lights on CV pathogenesis and mechanisms of relapse and, therefore, to increase the relevance of autoimmune diseases in CV epidemiology. Specific B-cell clones are involved in the production of pathogenic immune complexes that leads to small-vessel vasculitis. Therefore, both antiviral treatments [direct-acting antivirals (DAAs) and oral nucleot(s)ide analogues] and targeted anti-CD20 therapies (rituximab) prove to be safe and effective options, leading to a better prognosis. Association of Sjögren syndrome and CV defines a specific phenotype of patients, characterized by severe manifestations and poor outcome.

SUMMARY

Removing viral stimulation on B-cells through direct-acting antivirals and blocking B-cells proliferation and differentiation with rituximab are the goals of treatment of CV. However, further research is needed to identify prognostic factors of refractory and relapsing disease.

Serological and Molecular Characterization of Hepatitis C Virus-Related Cryoglobulinemic Vasculitis in Patients without Cryoprecipitate

Prolonged B cells stimulation due to the Hepatitis C virus (HCV) can result in autoimmunity, stigmatized by rising levels of cryoglobulins (CGs), the rheumatoid factor (RF), and free light chains (FLC) of immunoglobulins (Ig) associated with a range of symptoms, from their absence to severe cryoglobulinemic vasculitis and lymphoma. Here, we aimed to identify an immunological signature for the earliest stages of vasculitis when cryoprecipitate is still not detectable. We firstly analyzed the IgG subclasses, FLC, and RF in 120 HCV-RNA-positive patients divided into four groups according to the type of cryoprecipitate and symptoms: 30 asymptomatic without cryoprecipitate (No Cryo), 30 with vasculitis symptoms but without CGs that we supposed were circulating but still not detectable (Circulating), 30 type II and 30 type III mixed cryoglobulinemia (Cryo II and Cryo III, respectively). Our results revealed that patients with supposed circulating CGs displayed a pattern of serological parameters that closely resembled Cryo II and Cryo III, with a stronger similarity to Cryo II. Accordingly, we analyzed the groups of Circulating and Cryo II for their immunoglobulin heavy chain (IgH) and T-cell receptor (TCR) gene rearrangements, finding a similar mixed distribution of monoclonal, oligoclonal, and polyclonal responses compared to a control group of ten HCV-RNA-negative patients recovered from infection, who displayed a 100% polyclonal response. Our results strengthened the hypothesis that circulating CGs are the origin of symptoms in HCV-RNA-positive patients without cryoprecipitate and demonstrated that an analysis of clonal IGH and TCR rearrangements is the best option for the early diagnosis of extrahepatic complications.

Hepatitis C virus-associated B-cell lymphomas: The importance of the new direct antiviral agent therapy

Hepatitis C virus (HCV) is a hepatotropic and lymphotropic virus, responsible for both chronic hepatitis and extra-hepatic manifestations. Multiple epidemiologic, clinical, biological, and molecular studies have suggested that HCV plays a causal role also in the development of several lymphoproliferative disorders, either benign, such as mixed cryoglobulinemia, or malignant, such as B-cell non-Hodgkin lymphomas (NHL). Chronic viral antigenic stimulation of B-lymphocytes plays a fundamental basic role from the onset of lymphoma to its final steps. In the past, several studies demonstrated that the association of pegylated interferon plus ribavirin was able to eradicate HCV, with subsequent regression of indolent B-cell low-grade NHL. Other studies have demonstrated that direct antiviral agents (DAAs) therapy have some efficacy in HCV-associated NHL, particularly in patients with low-grade NHL or marginal zone-lymphoma, but these results need to be confirmed in larger studies with longer follow-up. The response rate of antiviral therapy seems favorable also in high grade NHL when DAAs therapy is administered in combination with chemotherapy and therefore antiviral therapy should be considered as a first-line approach in HCV-related NHL.