DNA CELL CONTENT STUDIES IN MULTIPLE-MYELOMA

Here the current studies in cell DNP, content of plasma cells (PC), fr om multiple myeloma (MM) patients is reviewed, focusing on two complem entary aspects the detection of clonal abnormalities and the identific ation 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 b eing hyperdiploid. Comparing hyperdiploid with diploid patients, the f ormer seem to display a better prognosis. Fluorescence in situ hybridi zation studies have confirmed that there is a high incidence of numeri cal chromosome abnormalities in MM and that trisomies are significantl y more common than monosomies (84% vs 14%). The most frequent gains ca n 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 doub le staining technique may be an alternative to other more laborious me thods of assessing the PC labelling index, Thus, patients with >3% S-p hase PC detected by FCM have an adverse prognosis and this parameter i s one of the most important independent prognostic criteria for predic ting survival in MM patients. Moreover, the number of S-phase PC, toge ther with other prognostic factors, such as beta 2microglobulin, age a nd performance status can be a very useful tool for stratifying patien ts into groups in order to establish risk-directed therapeutic protoco ls.