Cell cycle analysis of Waldenstrom's macroglobulinemia.
Little is known about the DNA cell content and cell cycle characteristics of immunoglobulin (Ig) M monoclonal gammopathies. The autonomous clone appears to be rather heterogeneous, from mature B lymphocytes to plasma cells (PCs). We have evaluated the DNA cell content of 27 patients with IgM monoclonal gammopathies: 18 of them had Waldenstrom's macroglobulinemia (WM), and 9 were diagnosed with IgM-monoclonal gammopathy of undetermined significance (MGUS). To specifically analyze the cell cycle of the B lymphocyte and PC populations, we used a flow-cytometric double-staining technique with CD19/CD20/CD22 propidium iodide for B lymphocytes and CD38/CD138 propidium iodide for PCs. In 26 of 27 patients, both subsets of tumor cells (B lymphocyte and PC) showed a diploid DNA cell content (DNA index, 1). The median percentage of proliferating B lymphocytes, S-phase + G2/M-phase, was 1.8% (range, 0.4%-4.1%). This proliferative activity was significantly lower than that observed in nonmalignant cells (5.7%; range, 0.1%-14.2%; P = 0.004) in the same sample. No differences were observed when comparing the proliferative activity of WM with that of IgM MGUS (median, 1.7% vs. 2.2%, respectively). Cell cycle characteristics of PCs were simultaneously evaluated in 9 patients, with 1.8% cells in S phase or G2/M phase. In summary, the cell cycle analysis showed that IgM monoclonal gammopathies are low-proliferative disorders, with a DNA ploidy pattern (diploid) clearly different from that of multiple myeloma.
Ocio
Enrique M
EM
Hematology Service, Hospital Universitario de Salamanca, Paseo san Vicente 58-182, 37007 Salamanca, Spain.
Mateo
Gema
G
Vidriales
Belen
B
Lopez-Berges
M Consuelo
MC
Garcia-Sanz
Ramon
R
Hernandez
Jesus M
JM
Orfao
Alberto
A
San Miguel
Jesus F
JF
D002453:Cell Cycle; D049109:Cell Proliferation; D004247:DNA / Q000032:analysis*; D005434:Flow Cytometry; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology*; D009101:Multiple Myeloma / Q000235:genetics / Q000503:physiopathology; D010950:Plasma Cells / Q000502:physiology; D011003:Ploidies; D008258:Waldenstrom Macroglobulinemia / Q000235:genetics* / Q000276:immunology / Q000503:physiopathology*
D007075:Immunoglobulin M; D004247:DNA