流式免疫表型特征在判断二次或三次打击淋巴瘤生存结局中的临床价值

Clinical value of flow immunophenotypic characteristics in predicting the survival outcome of double/triple-hit lymphoma

目的确立二次或三次打击淋巴瘤(double/triple-hit lymphoma,D/THL)流式细胞免疫表型(flow cytometric immunophenotyping,FCI)特征,分析其与B淋巴细胞白血病(B-LBL)在免疫表型上的差异,并探讨流式免疫表型特征与D/THL生存结局的相关性。方法用多色FCI分析法对40例D/THL患者和25例B-LBL患者的骨髓和外科活检样本免疫表型进行检测和评价,并将流式免疫表型结果与基因亚型以及总体生存率进行统计学分析。结果 90%(36/40)的D/THL病例CD10表达呈阳性,48%(19/40)的病例缺乏表面轻链,45%(18/40)的病例CD45表达呈弱阳性,40%(16/40)CD19表达呈弱阳性,43%(17/40)CD20表达呈弱阳性,28%(11/40)伴随CD19和CD20的弱表达,38%(15/40)的CD19和CD20表达呈差异化表达(variable expression)。Bcl2^+/Myc^+、Bcl6^+/Myc^+和Bcl2^+/Bcl6^+/Myc^+3种基因亚型D/THL之间,Bcl2^+/Myc^+组CD45弱表达和CD20差异表达的发生率明显低于Bcl2^+/Bcl6^+/Myc^+组(P=0.03,0.02);Bcl2^+/Myc^+组中Bcl2阳性率为96%,其他基因亚型组阳性率均为0,差异有统计学意义(P=0);其他流式免疫表型特征发生率差异均无统计学意义。B-LBL的CD45和CD20弱表达发生率明显高于D/THL(χ~2=20.78、20.83,P<0.01);D/THL病例CD19和CD20同时弱表达发生率(28%)稍多于B-LBL病例(12%),但差异无统计学意义(χ~2=2.19,P>0.05);B-LBL的Td T阳性发生率明显高于D/THL(χ~2=30.74,P<0.01)。对30例已经死亡患者进行生存分析显示,不同基因型总体生存率差异无统计学意义(Bcl2^+/Myc^+对Bcl6^+/Myc^+,P=0.08;Bcl2^+/Myc^+对Bcl2^+/Bcl6^+/Myc^+,P=0.13;Bcl6^+/Myc^+对Bcl2^+/Bcl6^+/Myc^+,P=1.0);CD45弱表达和Bcl2阳性预示着较低的总体生存率(χ~2=11.2、10.4,P=0.01、0.015)。结论 D/THL与B-LBL都可以出现CD45和CD20弱表达及Td T阳性,但B-LBL的生存率明显高于D/THL。D/THL患者的CD45弱表达和Bcl2阳性预示着较低的总体生存率。

Objective To establish the features of flow cytometric immunophenotyping（ FCI） of double/triple-hit lymphoma（ D/THL）,study the differences with B-lymphoblastic leukemia（ B-LBL） and explore the correlation between flow cytometric features and survival outcome of D/THL.Methods Multi-color FCI analysis was used to detect and evaluate the immunophenotype of bone marrow cells and surgical biopsy samples from 40 patients with D/THL and 25 patients with B-LBL. The flow immunophenotypes and gene subtypes were tested. The correlations of the tested results with overall survival rate were statistically analyzed. Results Most of the D/THL patients（ 90%,36/40） were CD10 positive and 48%（ 19/40） of the patients lacked light chain of surface.CD45 was underexpressed in 45%（ 18/40） of the patients. CD19 and CD20 were under-expressed in 40%（ 16/40） and 43%（ 17/40） of the patients respectively,in which both CD19 and CD20 were simultaneously under-expressed in 28%（ 11/40） of the patients and showed variable expression in 38%（ 15/40） of the patients. Among the 3 subtypes of Bcl2~＋/Myc~＋,Bcl6~＋/Myc~＋and Bcl2~＋/Bcl6~＋/Myc~＋in D/THL cases,the incidences of under-expressed CD45 and variable expressed CD20 in Bcl2~＋/Myc~＋group were significantly lower than that in Bcl2~＋/Bcl6~＋/Myc~＋group（ P = 0. 03,0. 02）. The positive rate of Bcl2 in Bcl2~＋/Myc~＋group was 96% but it was 0 in other subtype groups with statistically significant difference（ P = 0）. The difference in the incidence of other flow immunophenotypic traits was not statistically significant. Compared with B-LBL,D/THL less frequently under-expressed CD45（ χ~2= 20.78,P〈0.01） and CD20（ χ~2=20.83,P〈0.01）. The incidence of weak expression of CD19 and CD20 in D/THL cases（ 28%） was slightly higher than that in B-LBL cases（ 12%）,but the difference was not statistically significant（ χ~2= 2.19,P〈0.05）. The incidence of positive Td T in B-LBL was significantly higher than that in the D/THL patients（ χ~2= 30.74,P〈0.01）. The survival analysis for 30 dead patients showed that there was no significant difference in the overall survival rate between different genotypes（ Bcl2~＋/Myc~＋to Bcl6~＋/Myc~＋,P = 0.08; Bcl2~＋/Myc~＋to Bcl2~＋/Bcl6~＋/Myc~＋,P= 0.13; Bcl6~＋/Myc~＋to Bcl2~＋/Bcl6~＋/Myc~＋,P= 1.0）. Of the assessed flow cytometric parameters,weak expression of CD45 and positive Bcl2 correlated with inferior survival rate（ χ~2= 11.2,10.4,P = 0.01,0.015）.Conclusion On immunophenotype,although both D/THL and B-LBL showed low expression of CD45 and CD20 with positive Td T,the survival rate of BLBL was significantly higher than that of D/THL. Weak expression of CD45 and positive expression of Bcl2 in D/THL patients may indicate low overall survival rate.