[Characteristics of drug resistance of tumor plasmocytes in vitro in patients with multiple myeloma differently responsive to chemotherapy]. / Kharakteristika lekarstvennoi ustoichivosti opukholevykh plazmotsitov in vitro u bol'nykh mnozhestvennoi mielomoi s razlichnym otvetom na khimioterapiiu.

ABSTRACT

AIM: To determine sensitivity of tumor plasmocytes in vitro to cytostatic drugs (prednisolone, alkeran belustin, vincristine, rubomycin, doxorubicin, cytarabin, methotrexate, cysplatin, etoposide). MATERIAL AND METHODS: The sensitivity was measured with DISC method in 12 patients with multiple myeloma (MM) in two groups resistant and responsive to induction polychemotherapy (PCT). RESULTS: The groups appeared significantly different by lowering of pathological paraprotein concentration (PIg) by 7.4 +/- 2.5% and 32.5 +/- 3.7%, respectively (p < 0.05). The resistance to the drugs was higher in the resistant patients than in the responders (0.7 +/- 0.28 versus 0.4 +/- 0.02, p < 0.05). PCT schemes of resistant patients contained 65.0 +/- 2.3% of ineffective drugs. In the responders the percentage was 35.7 +/- 5.3% (p < 0.05). CONCLUSION: The relationship exists between resistance of tumor plasmocytes to drugs in vitro and clinical findings.