Objective: To improve the understanding of the clinical and laboratory features of the IgM multiple myeloma (MM).
Methods: The clinical data of four cases of IgM MM patients were collected, their clinical and laboratory features were summarized and analyzed.
Results: Four patients met the criteria of IgM MM. They were all male. The age at the diagnosis ranged from 54 to 69 years. The primary symptoms included bone pain, hyperviscosity and bleeding. Three cases had κ-chain and only one case had λ-chain. They were all staged ⅢA according to the Durie-Salmon staging system (DSS). One case stagedⅠand three cases staged Ⅱ according to the international staging system (ISS). The average value of IgM, hemoglobin, serum calcium, creatinine and the proportion of bone marrow plasma cells were 83.6 (52.9-111.0) g/L, 79.5 (61.0-105.0) g/L, 3.20(2.11-6.00) mmol/L, 104.3 (56.0-171.0) μmol/L and 0.558 (0.290-0.775), respectively. Bone destruction was found in 3 cases. Immunophenotypes of bone marrow plasma cells were analyzed in 3 patients. Results showed that these cells expressed CD38 and CD138, and did not express CD19, CD20 and CD117. Chromosome and fluorescence in situ hybridization (FISH) analysis were carried out in 4 cases and found that all of them had IgH translocations and 1q21 amplification, 2 cases had 13q and 17p deletion, and 3 cases had t(11;14). Three patients received bortezomib-based regimens as induction therapy and reached partial response (PR) - very good partial response (VGPR). Followed up to November 30, 2012, the median progress-free survival (PFS) and overall survival (OS) of the 4 cases were only 6.0 (2.5-7.0) months and 17.5 (2.5-27.0) months, respectively.
Conclusions: IgM MM is very rare and is no more than 0.5% in all types of MM. IgM MM have frequent t(11;14) and amp(1q21). Bortezomib-based regimens are effective for it, however, the disease progresses rapidly and has poor prognosis.
目的 提高对IgM型多发性骨髓瘤（MM）患者临床及实验室特征的认识。方法 收集4例IgM型MM患者的临床资料，对其临床及实验室特征进行总结、分析。结果 4例患者符合IgM型MM的诊断。4例均为男性，年龄54~69岁，初发症状包括骨痛、高黏滞血症、出血，3例轻链为κ型，1例为λ型，Durie-Salmon（D-S）分期均为ⅢA期，国际分期系统（ISS）分期：Ⅰ期1例，Ⅱ期3例。平均IgM 83.6（52.9~111.0）g/L，HGB 79.5（61.0~105.0）g/L，血钙3.20（2.11~6.00）mmol/L，肌酐104.3（56.0~171.0）μmol/L，骨髓浆细胞比例0.558（0.290~0.775），3例存在骨质破坏。3例患者行免疫表型检测均表达CD38、CD138，不表达CD19、CD20、CD117。染色体、荧光原位杂交检查结果显示4例患者均有IgH易位和1q21扩增，2例伴有13q和17p缺失，3例明确为t(11;14)。3例予以硼替佐米为主的方案诱导化疗，达到部分反应至非常好的部分反应。随访至2012年11月30日，无进展生存时间仅6.0（2.5~7.0）个月，总生存时间仅为17.5（2.5~27.0）个月。结论 IgM型MM非常罕见，在所有类型MM患者中不到0.5%，细胞遗传学异常以t(11;14)和1q21阳性多见，硼替佐米为主的方案治疗有效，但患者病情进展迅速，总体预后较差。