Clonal B-cell populations in patients with idiopathic thrombocytopenic
purpura
D van der Harst, D de Jong, J Limpens, PM Kluin, Y Rozier, GJ van Ommen and A Brand
Department of Immunohaematology, Sylvius Laboratory, University Medical
Centre, Leiden, The Netherlands.
Idiopathic thrombocytopenic purpura (ITP) may be associated with other
autoimmune diseases and the development of lymphoproliferative
malignancies. In Sjogren's disease, Graves' disease, and essential mixed
cryoglobulinemia, which are also associated with the development of B-cell
neoplasia, clonal B-cell expansions have been detected. Eleven patients
with ITP were investigated for the presence of a clonal excess (CE) using
kappa-lambda flow cytometry and DNA analysis for rearrangement of
immunoglobulin heavy and light chain genes in blood and/or spleen
lymphocytes. In 10 of 11 patients, clonal B-cell populations were found by
one or both tests. In three of these patients, oligoclonal B-cell
populations were suggested by the combined findings. In all four patients
with a small paraproteinemia, the isotype was confirmed by either flow
cytometry or DNA rearrangement analysis. Our data suggest that the
oligoclonal expansions are not restricted to CD5+ B cells, as in the
majority of patients this subset was below the detection level of flow
cytometry or DNA rearrangement analysis. None of the patients developed
clinical manifestations of malignant lymphoma during a follow-up period of
10 to 44 months after sampling. We conclude that clonal excess populations
of B cells are not a unique feature of malignant lymphoma, but may occur in
autoimmune diseases, suggesting a benign (oligo)clonal B-cell
proliferation.
Volume 76,
Issue 11,
pp. 2321-2326,
12/01/1990
Copyright © 1990 by The American Society of Hematology
