CD138磁珠分选结合间期荧光原位杂交在浆细胞病遗传学诊断中的应用价值

Application Value of CD138 MACS-FISH in the Genetic Diagnosis of Plasma Cell Dyscrasia

目的:通过CD138磁珠分选(MACS)结合间期荧光原位杂交(I-FISH)技术研究浆细胞病的细胞遗传学特征,阐明MACS-FISH在浆细胞病遗传学诊断中的应用价值,以及探讨我国浆细胞病FISH检测标准化的问题。方法:收集初诊浆细胞病患者232例,其中MM 203例,AL淀粉样变性24例,意义未明单克隆免疫球蛋白血症(MGUS)5例。应用MACS-FISH检测浆细胞病的细胞遗传学异常。比较染色体核型分析、常规间期FISH(C-FISH)与MACS-FISH细胞遗传学异常检出率的差异。按骨髓浆细胞比例分组,比较C-FISH与MACS-FISH的检测敏感性。分析C-FISH、MACS-FISH异常阳性细胞率与浆细胞比例的相关性,以及比较C-FISH和MACS-FISH克隆大小的检出差异。结果:MACS-FISH检出MM、AL淀粉样变性、MGUS的细胞遗传学异常的发生率为分别为85.9%、62.5%和60%。应用染色体核型分析和C-FISH检出MM细胞遗传学异常的发生率分别为20.0%和64.7%,均显著低于MACS-FISH(P<0.001)。MACS-FISH检出14q32异位、del(14q32)、t(11;14)、+17p13和并存2种及≧3种细胞遗传学异常的阳性率均显著高于C-FISH检测结果(P<0.05)。当骨髓浆细胞比例≦5%时,MACS-FISH的阳性检出率显著高于C-FISH(P=0.001),且MACS-FISH在不同浆细胞比例分组的阳性检出率均无统计学差异;而C-FISH在浆细胞比例≦5%时的阳性检出率显著低于其余3组(P=0.013,P=0.001,P<0.001)。C-FISH组各遗传学异常和MACS-FISH组中+1q21、14q32异位的阳性细胞率与浆细胞比例呈显著正相关(P<0.05)。MACSFISH组各种细胞遗传学异常的克隆大小显著大于C-FISH组(P<0.001)。结论:MACS-FISH可以显著提高浆细胞病细胞遗传学异常的检出率,能更好的反映浆细胞病的细胞遗传学异常发生情况及其克隆大小。MACS-FISH可推荐作为国内浆细胞病遗传学诊断的标准方法,用于MM和SMM的危险分层,以及MGUS、AL淀粉样变性的遗传学诊断和研究。

Objective：To investigate the cytogenetic characteristics of the various plasma cell dyscrasia using the CD138 MACS-FISH,to elucidate the application value of MACS-FISH in the genetic diagnosis of plasma cell dyscrasia,and to explore the standardization of FISH detection for plasma cell dyscrasia.Methods：A total of 232 patients with newly diagnosed plasma cell dyscrasia were collected,including 203 cases of MM,24 cases of AL amyloidosis and 5cases of MGUS,whose cytogenetic abnormalities were detected by MACS-FISH,and the differences of the positive detection rates of chromosome karyotype analysis,C-FISH and MACS-FISH in MM cytogenetic abnormality were compared.The sensitivity of C-FISH and MACS-FISH were analyzed and compared according to the proportion of bone marrow plasma cells.The correlation between the positive cell rates of C-FISH and MACS-FISH and the proportion of plasma cells were analyzed respectively.The differences in the clone size detected by C-FISH and MACS-FISH were compared.Results：The incidence of cytogenetic abnormality of MM,AL amyloidosis and MGUS detected by MACSFISH were 85.9%,62.5%,60%,respectively.The incidence rate of MM cytogenetic abnormality detected by Chromosome karyotype analysis and C-FISH were 20.0%and 64.7%,respectively,which were significantly lower than that of MACS-FISH（P〈0.001）.The positive rate of 14q32 translocation,del（14q32）,t（11;14）,＋ 17pl3 and the coexistence of 2 and ≥3 kinds of cytogenetic abnormalities detected by MACS-FISH were significantly higher than that detected by C-FISH（P〈0.05）.When the plasma cell ratio was less than or equal to 5%,the positive detection rate of MACS-FISH was significantly higher than that of C-FISH（P= 0.001）,and there was no significant difference in different plasma cell proportion group of MACS-FISH.However,when the plasma cell ratio was less than or equal to5%,the positive detection rate of C-FISH detection was significantly lower than that of the other 3 groups（P=0.013,P= 0.001,P〈0.001）.The positive cell rates of all cytogenetic abnormalities in C-FISH group and ＋ 1q21 and 14q32 translocation in MACS-FISH group were significantly positively correlated with the proportion of plasma cells（P〈0.05）.The clone size of various cytogenetic abnormalities in MACS-FISH group were significantly higher than that in C-FISH group（P〈0.001）.Conclusion：MACS-FISH may significantly enhance the detection rate of cytogenetic abnormalities in various plasma cell dyscrasia,and it can better reflect the cytogenetic abnormality of plasma cell dyscrasia and its clone size.MACS-FISH may be recommended as a standard method for the genetic diagnosis of plasma cell dyscrasia,the risk stratification of MM and SMM,as well as the genetic diagnosis and research of MGUS and AL amyloidosis.