MONOCLONAL LYMPHOCYTE-PROLIFERATION AND BCL-2 REARRANGEMENT IN ESSENTIAL MIXED CRYOGLOBULINEMIA

A patient with essential mixed cryoglobulinaemia (EMC) type II and hep atitis C virus (HCV) infection, in whom immunophenotypic and genotypic studies demonstrated a clonal proliferation of B lymphocytes, is desc ribed. Fluorescent in situ hybridization with probes to Ig heavy chain gene and to the oncogene bcl-2 demonstrated a translocation of bcl-2 to the immunoglobulin heavy chain locus on chromosome 14. A sharp rise in the level of the monoclonal IgM was associated with a second genet ic aberration [t(8:22) (q24:q11)]. No other clinical evidence of disea se progression could be demonstrated. Low grade lymphoproliferative di sorder with typical cytogenetic abnormalities developed on the backgro und of EMC and HCV. Clinical progression was associated with a second genetic abnormality involving the myc oncogene. It is possible that HC V chronic infection may indirectly influence oncogenes associated with lymphoma.