The IgMk rheumatoid factors (RF) of type II mixed cryoglobulinaemia (MC) react, in 95% of cases, with MoAbs against the cross-reactive idiotypes (CRI) Cc1 or Lc1 (corresponding to the products of the VH1 and VH4 genes). MC is closely associated with HCV infection, a virus which infects lymphocytes and may replicate in B cells. It has been suggested that HCV may induce clonal selection of B cells producing monoclonal IgMk RF in type II MC. To verify whether HCV is enriched in B cells, and in the subsets expressing Cc1 and Lc1 CRI, we studied peripheral blood lymphocytes from eight patients with MC and HCV RNA-positive sera. Seven patients had RF reacting with anti-Cc1, the other with anti-Lc1 CRI. Total lymphocytes, T cells, B cells, and Cc1+ or Lc1+, Cc1− or Lc1− B cells were purified using MoAb-coated magnetic beads. Lymphocyte subsets were then diluted to give a range of 1 × 106−1 × 103 cells and tested for HCV RNA by reverse transcriptase-polymerase chain reaction. HCV was found exclusively in B cells in seven out of eight patients. In three patients HCV was enriched in the Cc1+ cells. In one of these patients, HCV was found exclusively in Cc1+ cells, with Cc1− cells being HCV−. The data indicate that B cells from type II MC patients are almost constantly infected by HCV. In selected cases, B cell subsets expressing IgMk RF CRI are the prevalent cell type infected by HCV. Our data suggest HCV involvement in B cell dysregulation leading to cryoprecipitable IgMk RF production.
|Titolo:||Hepatitis C virus (HCV) in lymphocyte subsets and in B lymphocytes expressing rheumatoid factor cross-reacting idiotype in type II mixed cryoglobulinemia|
|Parole Chiave:||Cryoglobulinaemia ; rheumatoid factor ; cross-reacting idiotypes ; hepatitis C virus ; lymphocyte subsets|
|Settore Scientifico Disciplinare:||Settore MED/42 - Igiene Generale e Applicata|
|Data di pubblicazione:||dic-2000|
|Digital Object Identifier (DOI):||10.1046/j.1365-2249.2000.01396.x|
|Appare nelle tipologie:||01 - Articolo su periodico|