Human myeloma: several subsets of circulating lymphocytes express plasma cell-associated antigens.
Peripheral blood lymphocytes from 9 monoclonal gammopathies of undetermined significance (MGUS) and 27 multiple myelomas (MM) were studied with a panel of monoclonal antibodies (MoAb) that recognize B and T lymphocytes and plasma cells. No difference in the percentage of B lymphocytes, identified by B1 and B4 MoAb, was observed in MGUS and MM patients versus normal controls. However, high percentages of circulating lymphocytes expressing plasma cell-associated antigens were detected in MM (HAN-PC1+ = 29.4 +/- 20.4%; TEC-T10+ = 27.8 +/- 19.2%) whereas they were in the normal range in MGUS (HAN-PC1+ = 8.8 +/- 5.8% p = 0.006; TEC-T10+ = 5.7 +/- 4.7% p less than 0.001). Almost identical results were obtained using PCA-1 MoAb in 17 of these patients. TEC-T10+ and PCA-1+ lymphocytes were sorted and re-analyzed with phycoerythrin conjugated MoAb in 3 healthy subjects, 2 MGUS, and 4 MM patients. In normal subjects and in MGUS the majority of PCA-1+ cells belonged to the B lineage (Leu 2-, Leu3-, Leu 15-, HLA-Dr+), whereas the majority of TEC-T10+ cells are represented by activated T cells and NK cells (Leu 15+). In MM an abnormal expansion of T lymphocytes was chiefly responsible for the high values of lymphocytes expressing plasma cell-associated antigens. Moreover, in MM a clinical evaluation showed a correlation between the presence of these lymphocytes and an aggressive disease. Indeed, they can be considered a useful prognostic marker.
Boccadoro
M
M
Cattedra di Ematologia, University of Torino, Italy.
Omedé
P
P
Massaia
M
M
Dianzani
U
U
Pioppo
P
P
Battaglio
S
S
Meregalli
M
M
Pileri
A
A
D000911:Antibodies, Monoclonal / Q000276:immunology; D000941:Antigens / Q000032:analysis; D006801:Humans; D006942:Hypergammaglobulinemia / Q000276:immunology / Q000473:pathology; D009101:Multiple Myeloma / Q000276:immunology* / Q000473:pathology; D010950:Plasma Cells / Q000276:immunology*; D011379:Prognosis
D000911:Antibodies, Monoclonal; D000941:Antigens