OBJECTIVETo evaluate the effect of modified culture method used to cytogenetic analysis and the clinically significance of chromosomal abnormalities to multiple myeloma (MM).

METHODSMononuclear cells were isolated from bone marrow aspirate of 20 MM patients; and then cultured for 3 days without any cytokines, and 6 days in the presence of IL-6 (10 ng/mL) and GM-CSF (30 ng/mL) before RHG banding analysis; the remained part of aspirates were treated directly. Eight cases of iron deficiency anemia were taken as control.

RESULTSThe experiment was failure in 2 cases because of blood clot, and another 2 cases could be analyzed only by direct method due to inadequate cells. The karyotype abnormalities were found from 4 cases of 16 available patients. Of them, three cases had complex karyotypes. The abnormalities were detected after 6 days culture with addition of cytokines. No abnormalities were detected from those groups of directly analysis and 3 day culture. Meantime, the clinical data showed that the patients with cytogenetic abnormalities were in stage III, and had a high percentage of MM cells (25%-56%) in their bone marrow, and also poor responses to prior chemotherapy. No cytogenetic abnormalities were found from control individuals in all groups.

CONCLUSIONExtended culture in the presence of cytokines could improve the efficiency of cytogenetic analysis to MM. Complex karyotype was common cytogenetic abnormalities in MM patients with poor response to chemotherapy.