OBJECTIVETo study the significance of detecting the plasma level of matrix metalloproteinase-13(MMP-13) in patients with multiple myeloma(MM) and to investigate the correlation of MMP-13 levels in MM patients with myeloma bone disease(MBD).

METHODSThe plasma level of MMP-13 was quantitatively analyzed in 53 newly diagnosed MM patients and 30 healthy controls by enzyme-linked immunosorbent assay(ELISA). Imaging examination was used to determine bone damage in patients with MM. At the same time, using a dual-energy X-ray absortionmetry(DXA), the bone mineral density was examined on vertebra L2 to L4 in the anteroposterior position and the proximal left femur in 17 MM patients and 15 healthy controls.

RESULTSThe plasma level of MMP-13 in MM patients was significantly higher than that in the controls(P<0.01), and the MMP-13 level in MM patients with stage III of International Staging System(ISS) was significantly higher than that in patients with stage I-II(P<0.01). The MMP-13 level in MM patients without MBD was significantly higher than that in the controls(P<0.05). According to bone disease grading, 53 patients were divided into group A(bone grade 0-2, n=18)and group B(bone grade 3-4, n=35). Compared with group A, MMP-13 level group B was enhanced significantly (P<0.01). Further analyses revealed that the level of MMP-13 negatively correlated with the bone mineral density on L2 to L4, greater trochanter and Ward's triangle(r values were -0.693, -0.575 and -0.575, respectively, P<0.05), but not correlated with left femoral neck(r= -0.339)(P>0.05).

CONCLUSIONThe level of MMP-13 in MM patients is significantly high, and closely relates with ISS clinical stage, degree of MBD and the bone mineral density of MM patients. MMP-13 plays an important role in the development of MBD.