多发性骨髓瘤伴无症状性高iPTH血症分析

The Analysis of Multiple Myeloma with Asymptomatic High iPTH

目的研究并分析多发性骨髓瘤伴高血清iPTH的原因。方法采用聚乙二醇沉淀法去除血清IgG,比较去除IgG前后血清iPTH的浓度;行影像学及钙、磷代谢指标检查,了解甲状旁腺功能情况;随访化疗前后血清iPTH浓度的动态变化。结果去IgG的血清与未去IgG的血清相比,iPTH浓度无明显差别,二者均高于正常;甲状旁腺扫描及血钙、磷?碱性磷酸酶和24 h尿钙、磷排泄量均在正常水平;化疗后,血清IgG水平与血iPTH浓度均恢复正常。结论该多发性骨髓瘤患者高iPTH血症的原因可能是骨髓瘤细胞本身分泌iPTH,或是骨髓瘤细胞分泌的IgG对甲状旁腺细胞iPTH分泌的刺激作用,而非高血清IgG对iPTH测定的干扰作用。该患者临床上无甲状旁腺功能亢进的表现和生化特征,提示分泌的iPTH可能仅有免疫活性而无或仅有低生物活性。

Objective To study and analyze one case with a multiple myeloma with high serum iPTH. Methods We found the multiple myeloma patient with high iPTH, but symptoms and biochemical changes had no existent evidence of hyperparathyroidism. In order to identify the reasons, first, we used polyethylene glycol to remove serum IgG and compared the serum concentrations of iPTH before and after the removal of IgG; second, we used imaging and calcium phosphorus metabolism check to understand the situation of parathyroid function; third, we checked the dynamic changes of iPTH before and after chemotherapy. Results First, the iPTH had no significant differences, both higher than normal ; second, blood calcium and parathyroid scan, alkaline phosphate and 24-hour calcium and phosphorus excretion were both in normal levels; third, after chemotherapy, the serum levels of IgG and iPTH were back to normal. Conclusion The multiple myeloma patient with high iPTH may be due to myeloma cells producing iPTH, or myeloma cells secreted IgG stimulated the parathyroid cells secreting iPTH, rather than high serum IgG interfered the determination of iPTH. The patient without clinical manifestations of hyperparathyroidism and biochemical characteristics, suggested that the secretion of iPTH should be only with immune activity or only low biological activity.