The effectiveness of rituximab in hepatitis C virus (HCV)–related mixed cryoglobulinemia (MC) has been shown. However, the risk of an increase in viral replication limits its use in cirrhosis, a condition frequently observed in patients with MC. In this prospective study, 19 HCV-positive patients with MC and advanced liver disease, who were excluded from antiviral therapy, were treated with rituximab and followed for 6 months. MC symptoms included purpura, arthralgias, weakness, sensory-motor polyneuropathy, nephropathy, and leg ulcers. Liver cirrhosis was observed in 15 of 19 patients, with ascitic decompensation in 6 cases. A consistent improvement in MC syndrome was evident at the end-of-treatment (EOT) and end-of-follow-up (EOF-U). Variable modifications in both mean viral titers and alanine aminotransferase values were observed at admission, EOT, third month of follow-up, and EOF-U (2.62 × 10⁶, 4.28 × 10⁶, 4.82 × 10⁶, and 2.02 × 10⁶ IU/mL and 63.6, 49.1, 56.6, and 51.4 IU/L, respectively). Improvement in liver protidosynthetic activity and ascites degree was observed at EOT and EOF-U, especially in more advanced cases. This study shows the effectiveness and safety of rituximab in MC syndrome with advanced liver disease. Moreover, the depletion of CD20⁺ B cells was also followed by cirrhosis syndrome improvement despite the possibility of transient increases of viremia titers.

Immune synapse formation between dendritic cells (DCs) and T cells is one of the key events in immune reaction. In immunogenic synapses, the presence of fully mature DCs is mandatory; consequently, the modulation of DC maturation may promote tolerance and represents a valuable therapeutic approach in autoimmune diseases. In the field of cell therapy, bone marrow mesenchymal stem cells (MSCs) have been extensively studied for their immunoregulatory properties, such as inhibiting DC immunogenicity during in vitro differentiation and ameliorating in vivo models of autoimmune diseases (e.g., experimental allergic encephalomyelitis). MSCs seem to play different roles with regard to DCs, depending on cell concentration, mechanism of stimulation, and accompanying immune cells. The aim of this work was to elucidate the immunogenic effects of MSC/DC interactions during DC activation (LPS stimulation or Ag loading). Human monocyte-derived DCs, bone marrow-derived MSCs, and circulating lymphocytes obtained from healthy donors, as well as the laboratory-generated influenza virus hemagglutinin-derived peptide, aa 306–318 peptide-specific T cell line were used for this study. We demonstrate that MSCs mediate inhibition of DC function only upon cell–cell contact. Despite no modification observed in cell phenotype or cytokine production, MSC-treated DCs were unable to form active immune synapses; they retained endocytic activity and podosome-like structures, typical of immature DCs. The transcriptional program induced by MSC–DC direct interaction supports at the molecular pathway level the phenotypical features observed, indicating the genes involved into contact-induced rearrangement of DC cytoskeleton.