Cell Surface Phenotype in Chronic Lymphocytic Leukemia

Abstract

Chronic lymphocytic leukemia (CLL) is very rare in Japan, in comparison with the prevalance of CLL in the United States of America and Europe.
Moreover, it has been reported that isotype of surface-membrane immunoglobulin (Sm-Ig) of CLL cells is different, characterized by the high incidence of IgG isotype or Sm-Ig^- in Japan.
In this series, Sm-Ig and surface antigens of peripheral mononuclear cells from Japanese CLL patients were analysed by a laser flow cytometry system (Spectrum III/Ortho Diagnostic System).
Monoclonal Sm-Ig was identified in 15 of 18; 6 of the 15 patients bore IgM isotype, 7 bore IgM and IgD isotype and 2 bore IgG isotype. The ratio of the kappa to lambda light chain type of Sm-Ig was 6 to 9 in our series. These Sm-IgM with or without IgD were faintly stained.
Cells from 9 CLL patients reacted with the monoclonal antibodies anti-Leu-1, anti-B1, anti-B2, anti-B7 and anti-HLA-DR and unreacted with monoclonal antibodies anti-Leu-2a, anti-Leu-3a and anti-IL2-R.
The data obtained in these cases are in agreement with the experience of other investigators in the USA and Europe.
Therefore, it is clarified that cell surface characterization of Japanese CLL cells is not different from that of European and American cases.