Regarding circulating CD19+ cells in multiple myeloma patients, it is our experience that while some patients do have a small number of circulating B cells expressing the same Ig idiotype as the myeloma paraprotein (King & Nelson, Blood 73:1925-35, 1989), the ratio of CD19+K+/CD19+lambda+ cells in the blood of myeloma patients is normal (King & Radicchi, Brit J Haem 81:218-22, 1992). Reported "clonal B-cell excess" in the blood of myeloma patients is usually probably a result of mistaking non-B cells (NK cells) bearing cytophilic paraprotein for B cells. Malcolm King Dept Clinical Immunology Royal North Shore Hospital St Leonards NSW 2065 Australia >>> Ierachmiel Daskal <DASKALI@einstein.edu> 10/09/01 04:55am >>> Please consult the paper of Bergsagel et al ( Blood 85:436-447 (1995)) for a complete review of the CD19 status in MM, pre and post Rx. Your question does not identify if this refers to the peripheral blood of BM. The presence of CD19 in plasma cells should not be the diagnostic corner stone for MM. As a matter of fact patient with MM have 2-8 times more circulating CD19 positive cells than normal individuals. Of course the prerequisite is that these are monotypic ( restricted to one of the light chains), as well as CD19/CD38 or CD138 which is more specific. MM cells are also positive for CD56 and CD58 which are absent from normal plasma cells. Knowles in his latest edition of "Neoplastic Hematopathology "actually claims that malignant Plasma cells are negative for ...CD19 (!) With respect to MGUS the basic criteria is a total serum gamma globulin concentration less than 3.5gm/dl no BJ proteins and no other clinical presentation. Hope this is more helpful than confusing. Ierachmiel Daskal M.D. PhD. FCAP, FASCP Chairman Department of Pathology and Laboratory Medicine (215) 456-6126 Pager: 2-3559 daskali@einstein.edu >>> "Wal & Sue Sharp" <walnsue@cableinet.co.uk> 10/06/01 08:16AM >>> Eyup me owd Flowers (Yorkshire slang), I'd like to try and get a consensus on two related topics - 1) Is CD19 positivity in plasma cells definitive of Myeloma or can you get reactive plasma cells showing the same ? 2) Does the list believe that even a small number of these cells in bone marrow justifies the diagnosis of Myeloma when clinical evidence (or rather, lack of it) would normally support MGUS ? I have my own thoughts on the matter but I thought it would be interesting to get wider opinions. Wal Sharp Yorkshire UK ********************************************************************* This message is intended for the addressee named and may contain confidential information. If you are not the intended recipient, please delete it and notify the sender. Views expressed in this message are those of the individual sender, and are not necessarily the views of NSW Health. *********************************************************************
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