1. Hepatitis B virus causes mixed cryoglobulinaemia by driving clonal expansion of innate B-cells producing a VH1-69-encoded antibody.
- Author
-
Visentini M, Pascolini S, Mitrevski M, Marrapodi R, Del Padre M, Todi L, Camponeschi A, Axiotis E, Carlesimo M, De Santis A, Fiorilli M, and Casato M
- Subjects
- Adult, Aged, Aged, 80 and over, Antibody Formation, Female, Humans, Immunity, Innate, Male, Middle Aged, B-Lymphocytes immunology, Cryoglobulinemia etiology, Hepatitis B complications, Immunoglobulin Heavy Chains genetics, Immunoglobulin Variable Region genetics
- Abstract
Objectives: To investigate the expression of a VH1-69-encoded idiotype, and the phenotypic and functional features of monoclonal B-cells from patients with type II mixed cryoglobulinaemia (MC) secondary to chronic hepatitis B virus (HBV) infection., Methods: B-cell immunophenotype and expression of a VH1-69-encoded idiotype were investigated by flow cytometry. B-cell proliferative responses to stimuli were investigated by the CFSE dilution assay., Results: Two out of five patients with chronic HBV studied had massive monoclonal expansion of VH1-69-expressing B-cells. These cells had the peculiar CD21(low) phenotype and low responsiveness to stimuli typical of the VH1-69-expressing B-cells commonly expanded in MC secondary to hepatitis C virus (HCV) infection. In both patients, anti-HBV therapy led to the regression of MC and of VH1-69+ B-cell expansion., Conclusions: VH1-69-encoded antibodies are known to preferentially recognise a variety of viral proteins including HCV E2, influenza A virus haemagglutinin and HIV gp41/gp120, and may serve as innate first line antiviral defense. Thus, like HCV, HBV may cause MC by protracted antigenic stimulation of VH1-69-expressing B-cells.
- Published
- 2016