Clonal expansion of abnormal B cells in old NZB XXXX .

@entity981 @entity19 @entity5 @entity899 @entity3512
The spleens of old NZB @entity19 have an abnormal population of B cells with extra chromosomes. These @entity981 B cells manifest increased proliferative capacity; they grow in (NZB X DBA/2)F1 spleens after intravenous injections. Molecular analysis of individual old NZB and F1 passaged spleens demonstrate that @entity981 cells represent a clonal or oligoclonal expansion of B cells. All spleens with at least 10% @entity981 cells demonstrated both heavy and kappa light chain immunoglobulin gene rearrangements by Southern blot hybridization. None of the @entity981 spleens from old NZB @entity19 had lambda rearrangements and only one of five showed evidence of clonal rearrangement of the TCR-beta gene. One also had a VK10 clonal rearrangement. Elevated @entity899 oncogene protein was observed in NZB @entity981 spleen cells; however, no @entity899 or other oncogene rearrangements or amplifications were seen. @entity981 cells were IgM-bright, IgD-dull, Ia+, dull B220, @entity3512 -, and Ly-1-dull. Spleens with @entity981 B cells had increased percentages of Ly-1 B cells. The data suggest that @entity981 cells in old NZB @entity19 represent clonal expansion of B cells and that they may represent an intermediate stage between autoimmunity and @entity5 .
