OBJECTIVETo study the plasma levels of urokinase-type plasminogen activator(u-PA) and its soluble receptor(suPAR )in patients with multiple myeloma(MM) and to evaluate their clinical significance.

METHODSPlasma u-PA and suPAR levels in 34 MM cases were measured with enzyme- linked immunosorbent assay (ELISA). The changes of plasma u-PA and suPAR levels in 6 MM cases were observed in succession before and after chemotherapy.

RESULTThe plasma u-PA and suPAR levels of MM patients were significantly higher than those of controls. The plasma u-PA and suPAR levels in the progress period was significantly higher than those in the stable period of MM patients as well as in controls (P<0.01), whereas there were no significant difference between the stable period of MM patients and controls (P>0.05). Among 6 cases,the plasma u-PA and suPAR levels after chemotherapy were significantly lower than those before chemotherapy (P<0.05). MM patients with tumor cells >20% in bone marrow smear had higher levels of plasma u-PA and suPAR than those with tumor cells <19% (P<0.05 P<0.01). The plasma u-PA and suPAR levels were positively correlated with the levels of serum globulin and the percentage of tumor cells in bone marrow,but negatively correlated with the levels of serum albumin.

CONCLUSIONPlasma u-PA and suPAR levels can serve as an index for clinical staging and assessing the therapeutic effect in MM patients.