多发性骨髓瘤患者骨密度的改变

目的 探讨多发性骨髓瘤（MM）患者骨密度改变的特点，评价双能X线骨密度仪（DXA）对MM患者骨密度（BMD）测量的价值。方法 采用Hologic QDR-2000型双能X线骨密度仪，测量34例MM患者及24例正常人全身、L2－4椎体正侧位及左股骨近端骨密度，动态监测免疫球蛋白G（IgG)型和未定型MM患者化疗前后的BMD；测定血清免疫蛋白、蛋白电泳、血钙和血磷。结果 （1）MM患者全身、腰椎、左股骨近端BMD明显低于正常人（P＜0．05）；（2）IgG型Ⅲ期患者BMD明显低于Ⅱ期（P＜0．05）；（3）IgG型腰椎BMD与IgG的变化呈负相关，而与全身、左股骨近端BMD无相关性；（4）MM常规化疗有效患者，腰椎BMD明显上升（P＜0．05），全身及左股骨折近端的BMD反而下降。结论 DXA是定量监测MM患者BMD变化和评价疗效和敏感方法。MM患者BMD降低经有效治疗是可逆转的，但腰椎与股骨近端骨损害及骨修复是不均一的。

The changes of bone mineral density in patients with multiple myeloma

Objective　To investigate the characteristics of change of the bone mineral density(BMD) in patients with multiple myeloma ( MM), and evaluate the use of Dual energy X-ray absorptiometry (DXA) to measure BMD in MM patients. Methods　Using a dual energy osteodensitometer Hologic QDR-2000, the BMD was examined on the whole body, vertebrate L2 to L4 in the antero-posterior and lateral position and the proximal left femur in both 34 MM patients and 24 normal individuals. The BMD of type IgG and unclassified patients were dynamically studied before and after chemotherapy, and the study also included serum immunoprotein, protein electrophoresis, blood calcium and phosphorus. Results　(1)Decrease of BMD of the whole body, vertebrate L2 to L4 in the antero-posterior and lateral position and the proximal left femur was significantly lower in MM patients compared with normal individuals（P<0.05）; (2) The BMD of stage III patients of type IgG was less than that of stage II patients′（P<0.05）; (3)Lumbar BMD of IgG type had nagative correlation with IgG change but without any association with the whole body and the proximal left femur BMD（P<0.05）; (4) After regular chemotherapy, the lumbar BMD increased rapidly, but the BMD of whole body and the proximal left femur decreased. Conclusion　DXA is a sensitive way to quantitatively study the BMD changes of MM patients and evaluate therapeutic effect. The BMD fall in MM patients can be reversed by effective therapy, but the osteal damage and restoration are not equivalent in the lumbar and proximal femur.