Improved cytogenetic analysis of bone marrow plasma cells after cytokine stimulation in multiple myeloma: a report on 46 patients

Abstract
Cytogenetic analysis was successfully performed in 46 consecutive myeloma patients (40 newly diagnosed and six relapsed patients). Karyotype was performed on bone marrow cells after long-term cultures (6 d) stimulated by GM-CSF, GM-CSF+IL6 or GM-CSF+IL6+IL3. Nineteen patients (41%) had cytogenetic abnormalities including 17/40 patients at diagnosis (42.5%) and 2/6 patients at relapse. Hyperdiploidy was found in 12 patients and hypodiploidy in four patients. Of the 17 newly diagnosed patients with cytogenetic abnormalities, five died from myeloma after 1-14 months and three other patients had primary drug resistance. Our results suggest that cytogenetic analysis after stimulation of cultures by cytokines detects clonal abnormalities in 40-50% of newly diagnosed myeloma patients and that these patients often have a short survival and/or primary drug resistance.