Detection of monoclonal B lymphocytes in bone marrow and peripheral blood of multiple myeloma patients by immunoglobulin gene rearrangement studies.
To investigate whether B lymphocytes are involved in the malignant cell clone of multiple myeloma (MM), we performed immunoglobulin gene rearrangement analysis of mononuclear cells and separated B lymphocytes, isolated from bone marrow and peripheral blood of MM patients. The B lymphocytes were separated by immunomagnetic beads, coated with an HLA class II specific antibody. Southern blot analysis with a JH probe revealed in the bone marrow of three out of seven patients identical immunoglobulin gene rearrangements in the B lymphocytes when compared to the plasma cells. Out of 10 patients, two patients with a high tumour burden were found to have monoclonal B lymphocytes in the peripheral blood. These results suggest that B lymphocytes in the bone marrow are part of the myeloma clone and that they can circulate in the peripheral blood. Although previous studies indicated that the ratio of K to lambda bearing lymphocytes in the peripheral blood can provide evidence for B cell monoclonality, we did not find a correlation between the results of K/lambda analysis and immunoglobulin gene rearrangement.
Van Riet
I
I
Department of Haematology and Immunology, Medical School of the Vrije Universiteit Brussel, Belgium.
Heirman
C
C
Lacor
P
P
De Waele
M
M
Thielemans
K
K
Van Camp
B
B
D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000276:immunology*; D015139:Blotting, Southern; D001853:Bone Marrow / Q000473:pathology; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin / Q000235:genetics*; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D009101:Multiple Myeloma / Q000235:genetics / Q000473:pathology*
D000911:Antibodies, Monoclonal