Cytogenetic studies have been carried out on bone marrow aspirates from 25 patients with myelomatosis. Abnormal stem lines were present in 7 of the patients; the remainder had a diploid chromosome complement. In most patients - also in those without an abnormal clone - some metaphases had a blurred appearance similar to that seen in bone marrow aspirates from patients with acute leukaemia. In many of the chromosome preparations obtained before cytostatic therapy some metaphases with structural aberrations on the chromosomes were seen. Evidence is presented that in the patients with abnormal stem lines in the bone marrow, the chromosome abnormalities are confined to the myeloma cells and are not found in the erythrocytic or granulocytic precursors, which thus do not seem to be involved by the neoplastic process. Based on the present resuts and on a review of the relevant literature some general cytogenetic features are emphasized which may contribute to a better understainding of the disorder. Especially, it is demonstrated that in myelomatosis the cytogenetic changes are much more uniform than in other malignant disorders with the exception of chronic myeloid leukaemia.
18 patients with acute non‐lymphocytic leukaemia were treated with Prednimustine, a chlorambucil ester of prednisolone, as a single drug. 5 patients responded with falling blast counts in peripheral blood, but only 1 obtained a complete remission of 3 months' duration. Since the activity of Prednimustine is lower than that of other commonly used drugs in acute non‐lymphocytic leukaemia, future studies should concentrate on other aspects, such as treatment of patients with steroid receptor‐positive blast cells or other types of leukaemia.
Abstract Chromosome studies were performed on bone marrow aspirates from 15 patients treated with azathioprine. In most patients the immunosuppressive therapy produced structural changes of the chromosome complement. The structural chromosome aberrations disappeared after cessation of therapy. In four patients no evidence of chromosome abnormalities could be found during therapy with azathioprine. It is proposed that the study of bone marrow cells may be more important than that of short‐term leukocyte cultures when estimating the chromosome damaging properties of some chemical agents.
A family with a tendency to thrombosis and decreased antithrombin III (AT III) activity in plasma, but normal immunoreactive AT III is reported. 7 members of the family had the AT III defect, 4 of whom have had thrombotic episodes. The importance of biological determination of AT III when studying patients with recurrent thrombotic episodes is emphasized.
Peripheral blood smears and bone‐marrow smears from 29 patients with malignant M‐components (25 with multiple myeloma and 4 with malignant lymphoma), 13 patients with benign monoclonal gammopathy (BMG), and 20 patients with polyclonal reactive plasmacytosis were examined by leucocyte alkaline phosphatase score (LAP‐score) and by acid phosphatase score in plasma cells from bone‐marrow smears. Furthermore, tissue sections from marrow biopsies from all patients were examined by the three‐layer unlabelled immunoperoxidase technique to detect cytoplasmic immunoglobulin. The LAP‐score was significantly higher in patients with malignant M‐components than in patients with BMG and also higher in IgA and IgG myeloma than in IgA and IgG BMG, but the latter difference was not significant. Furthermore, a significant positive correlation between paraprotein concentration and LAP‐score was found in multiple myeloma. Acid phosphatase score in plasma cells showed no clear distinction between multiple myeloma and BMG. Immunohistochemical examination showed a distinct monoclonal pattern in both multiple myeloma and BMG, allowing identification of the M‐cxsomponent which in all cases corresponded to the M‐component detected by serum examination. Cells producing immunoglobulin classes not matching the M‐component were more rare in multiple myeloma than in BMG, but the difference between the two conditions was quantitative and allowed no clear distinction.
