CYTOGENETIC STUDY IN MULTIPLE-MYELOMA AT DIAGNOSIS - COMPARISON OF 2 TECHNIQUES

Cytogenetic studies in multiple myeloma (MM) have been disappointing d ue to the low mitotic index of plasma cells. Recently the detection of clonal chromosomal abnormalities at diagnosis seemed to be improved b y addition of cytokines (IL-6 and GM-CSF) in the culture medium. We pe rformed two parallel total bone marrow cells culture types in 33 stage I, II and III multiple myeloma patients at diagnosis: 3 d without any cytokine, and 4-7 days stimulated with IL-6 and GM-CSF, No clonal chr omosomal abnormality was detected in the 12 stage I and II patients ei ther in 3 d or in 4-7 d culture. In stage III patients, abnormalities were observed in 18/21 (85.7%) and in 8/18 (44.4%) in the 3 d culture and the 4-7 d stimulated cultures respectively, Our results suggest th at in stage III multiple myeloma at diagnosis, 3 d culture without cyt okine may be the better technique to detect clonal chromosomal abnorma lities, and, before using cytokines as a reference condition, this 3 d unstimulated culture should be considered.