DNA Content Of Plasma Cells Research Articles

The flow-cytometric DNA content of the plasma cells of patients with multiple myeloma is a prognostic factor: a single institution experience

The flow-cytometric DNA content in the plasma cells of patients with multiple myeloma has been studied as a prognostic factor and contrasting results have been found. In a group of 45 patients with myeloma from a single institution, the DNA content of the malignant plasma cells was studied by means of flow cytometry: no patients were found to have hypodiploid DNA content, 14 patients had hyperdiploid DNA, and 31 patients were found to have diploid DNA. The overall survival of patients with hyperdiploid DNA was better than that of patients with diploid DNA: 93% at 85 months and 79% at 89 months, respectively; in both groups, the median overall survival has not been reached. No correlation was found between the DNA content and the International Staging System and the discriminatory effect of the DNA content was apparent only in the patients who were not autografted. It is concluded that the flow-cytometric DNA content of the plasma cells of patients with multiple myeloma may be a prognostic factor independent of others already identified and that myeloma patients with hyperdiploid DNA content in the plasma cells may have a better prognosis than those with a normal DNA content.

Hyperdiploidy Is a Common Finding in Monoclonal Gammopathy of Undetermined Significance and Monosomy 13 Is Restricted to These Hyperdiploid Patients

Two pathways, hyperdiploid and nonhyperdiploid, are proposed for progression to plasma cell neoplasia. Implication of monosomy 13 (Delta13) is unclear in monoclonal gammopathy of undetermined significance (MGUS), and data on DNA content of plasma cells [DNA index (DI)] are rare. We ascertained DI in 169 multiple myeloma (MM) and 96 MGUS patients. Interphase fluorescence in situ hybridization (FISH) coupled to cytoplasmic staining of specific Ig (cIg-FISH) was done to look for trisomies and to ascertain Delta13. Hyperdiploidy and hypodiploidy were found in 54% and 11.5% of MGUS patients and in 59.5% and 25% of MM patients, respectively. In MGUS patients tested using probes for odd chromosomes, cIg-FISH showed association between trisomies for chromosomes 3, 7, 9, 11, or 15 and hyperdiploidy. Delta13 was found in 45.3% and 24.6% of MM and MGUS patients, respectively. Most Delta13 cases observed in MGUS were found within hyperdiploid clones, 38% versus 11% in hypodiploid cases, in sharp contrast with the occurrence of Delta13 in MM patients, 31.9% and 76.3%, respectively. That peculiar distribution of Delta13 according to DI persisted with other thresholds used to ascertain hyperdiploidy, such as DI >or= 1.05. A strong relationship between IgA peak and hypodiploidy (P = 0.007) was only observed in MM, whereas lambda light chain was significantly associated with hypodiploidy in MGUS (P = 0.001) and MM (P = 0.05). Hyperdiploidy shows similar pattern in MGUS and MM. This fits well a hyperdiploid pathway leading to MM after a preceding MGUS stage. Yet-to-be-determined secondary event(s) needs to occur for the transition to MM, unrelated to changes in chromosome number or to loss of chromosome 13. In contrast, the "nonhyperdiploid" pathway needs to be clarified further because hypodiploidy is less common in MGUS than in MM and Delta13 is rare in hypodiploid MGUS patients compared with hypodiploid MM patients.

Is Flow Cytometric DNA Content Hypodiploidy Prognostic in Multiple Myeloma?

Hypodiploid multiple myeloma is uncommon when assessed by DNA content flow cytome-try, having been reported in less than 6% of patients with newly diagnosed multiple myeloma. Previous studies have shown these patients to be unresponsive to therapy and to have short survival. To address this further, we studied 349 of 504 patients eligible for Eastern Cooperative Oncology Group (ECOG) treatment trial E9486 and laboratory correlative study E9487 who had marrow mononuclear cells available for ploidy analysis. Marrow samples were studied by dual channel flow cytometry, using propidium iodide to measure the DNA content and kappa and lambda light chain antisera to identify the clonal cells. A DNA index < 0.95 was considered hypodiploid. Five patients (1.4%) were found to have hypodiploid DNA content in their marrow plasma cells. Three of the 5 patients with hypodiploid myeloma had a partial objective response to chemotherapy, which is not different from the overall objective response rate for all patients enrolled on E9486. All five patients with hypodiploid multiple myeloma died within 4 years from diagnosis, but these patients had a similar overall median survival (2.6 years) compared to the patients with diploid DNA content. Our studies confm the poorer survival of patients with diploid versus hyperdiploid myeloma; we cannot confii, however, the previously reported very poor outcome associated with hypodiploid myeloma using DNA content flow cytometry. Hypodiploid DNA content of plasma cells by flow cytometry may not be as ominous a factor as previously reported.

DNA cell content studies in multiple myeloma.

Here the current studies in cell DNA content of plasma cells (PC), from multiple myeloma (MM) patients is reviewed, focusing on two complementary aspects the detection of clonal abnormalities and the identification of the proliferative rate of PC. There is accumulating evidence that the measurement of cell DNA content by flow cytometry (FCM) is a useful parameter in the clinical evaluation of MM patients. Between 50 and 70% of MM patients display DNA aneuploidy, the majority of them being hyperdiploid. Comparing hyperdiploid with diploid patients, the former seem to display a better prognosis. Fluorescence in situ hybridization studies have confirmed that there is a high incidence of numerical chromosome abnormalities in MM and that trisomies are significantly more common than monosomies (84% vs 14%). The most frequent gains can be seen in chromosome 9 and 15 while the most common monosomies are those of chromosome 13 and X in females. The possibility of analysing the cell cycle distribution by using a propidium iodide (PI)/CD38 double staining technique may be an alternative to other more laborious methods of assessing the PC labelling index. Thus, patients with > 3% S-phase PC detected by FCM have an adverse prognosis and this parameter is one of the most important independent prognostic criteria for predicting survival in MM patients. Moreover, the number of S-phase PC, together with other prognostic factors, such as beta 2microglobulin, age and performance status can be a very useful tool for stratifying patients into groups in order to establish risk-directed therapeutic protocols.

Image analysis in multiple myeloma at diagnosis: Correlation with cytogenetic study

The DNA content of plasma cells (DNA Index or DI) was determined after Feulgen reaction using computed image analysis in 46 patients with multiple myeloma at diagnosis. Aneuploidy was found in 40 46 (87.0%) patients; 27 (58.7%) were hyperdiploid ( DI = 1.05–1.45), 11 (24.0%) were hypodiploid ( DI = 0.90–0.95), and two (4.3%) were biclonal. Cytogenetic study showed at least one abnormal mitosis in 21 46 (45.7%) cases. All patients with numeric changes had aneuploid DI, and thus confirmed DI ≥ 1.05 and DI ≤ 0.95 as good limits for aneuploidy with image analysis. Since abnormal karyotypes were observed mainly in stages II and III (55.6% and 54.5%, respectively) rather than in stage I (26.7%), aneuploid DI was found in most patients in all three stages, namely in all 15 15 (100%) patients in stage I. The prognostic value of aneuploidy was difficult to ascertain in our series. Hypodiploidy or DI > 1.15 was not especially associated with aggressive disease, as it was observed in 7 15 patients in stage I; however, with the same limits, patients with stages II and III were refractory to first-line chemotherapy. Image analysis is a highly sensitive method showing aneuploidy in most patients with MM at diagnosis and, in association with cytogenetic study, may help to better understand the pathogenesis of the disease. The independent prognostic value of aneuploidy was not fully established in this report.

Dual parameter analysis of myeloma cells by flow cytometry. DNA content of cells containing monotypic cytoplasmic immunoglobulin.

Dual-parameter flow cytometric analysis of monotypic cytoplasmic immunoglobulin (CIg) and DNA content on 15 myeloma marrows allowed S-phase determination of the CIg(+) tumor separately from the CIg(-) hematopoietic cell pool. The median percentage of the CIg(+) cells in S-phase was 2% compared with 5% for the CIg(-) cells. The median survival of patients with more than 2%, and those with 2% or less CIg(+) S-phase cells was 2 months and more than 13 months, respectively, from the time of study. Ploidy analysis identified four patterns of plasma cell DNA content: entirely hyperdiploid, entirely diploid, combined diploid and tetraploid stemlines, and tumors containing diploid and aneuploid CIg(+) cells. A monotypic CIg(+) double stemline myeloma was distinguished from two aneuploid tumors containing admixed normal, diploid polyclonal plasma cells. This technique provides an improved and expedient means for determining the proliferating fractions of myeloma cells and enhances recognition of double stemline tumors and clonal evolution in myeloma.

Plasma cell DNA content in multiple myeloma and related paraproteinemic disorders. Relationship with clinical and cytokinetic features

In 62 patients with multiple myeloma (MM) and related disorders, the nuclear DNA content distribution of bone marrow plasma cells was assessed by flow and conventional cytofluorometry. Abnormal distributions, suggesting the presence of aneuploid populations, were observed in 53% of MM at diagnosis, in 50% of benign monoclonal gammopathies and in 12% of Waldenström's macroglobulinemias. Eighty-six percent of aneuploid cases had DNA stem-lines falling between the diploid and triploid value. In advanced and relapsing MM, abnormal distributions were found in 75% of cases. In 4 out of 14 patients with MM serially studied during the course of disease, emergence of new abnormal clones was documented. The abnormal DNA content of bone marrow plasma cells was not correlated with any clinical and laboratory characteristic and it affected neither response to therapy nor survival in patients studied at diagnosis. In advanced phases of MM, the presence of abnormal clones was correlated with high plasma cell proliferation rates (studied by tritiated thymidine incorporation) and poor response to chemotherapy. Seven out of 8 patients in acute terminal phase of MM had abnormal clones. Among these, five had DNA stem-lines over triploid value.

Chemotherapy with cyclophosphamide, adriamycin and 5-fluorouracil (CAF) compared to che motherapy plus hormonal therapy with tamoxifen (T) in the treatment of advanced breast̄ cancer:An interim analysis

The DNA content of plasma cells (DNA Index or DI) was determined after Feulgen reaction using computed image analysis in 46 patients with multiple myeloma at diagnosis. Aneuploidy was found in 4046 (87.0%) patients; 27 (58.7%) were hyperdiploid (DI = 1.05–1.45), 11 (24.0%) were hypodiploid (DI = 0.90–0.95), and two (4.3%) were biclonal. Cytogenetic study showed at least one abnormal mitosis in 2146 (45.7%) cases. All patients with numeric changes had aneuploid DI, and thus confirmed DI ≥ 1.05 and DI ≤ 0.95 as good limits for aneuploidy with image analysis. Since abnormal karyotypes were observed mainly in stages II and III (55.6% and 54.5%, respectively) rather than in stage I (26.7%), aneuploid DI was found in most patients in all three stages, namely in all 1515 (100%) patients in stage I. The prognostic value of aneuploidy was difficult to ascertain in our series. Hypodiploidy or DI > 1.15 was not especially associated with aggressive disease, as it was observed in 715 patients in stage I; however, with the same limits, patients with stages II and III were refractory to first-line chemotherapy. Image analysis is a highly sensitive method showing aneuploidy in most patients with MM at diagnosis and, in association with cytogenetic study, may help to better understand the pathogenesis of the disease. The independent prognostic value of aneuploidy was not fully established in this report.