四色流式细胞术检测造血干细胞移植后急性B淋巴细胞白血病相关免疫表型及临床意义分析

Clinical significance of leukemia-associated immunophenotypes by 4 color flow cytometry after hemapoietic stem cell transplantation in adult and childhood B lineage acute lymphoblastic leukemia

目的探讨流式细胞术（FCM）检测造血干细胞移植（HSCT）后急性B淋巴细胞白血病（B—ALL）的白血病相关免疫表型（LAIP）及意义。方法采用以抗CD10／CD34／CD19／CD45为主的两组四色荧光标记抗体组合，对2005年1月至2007年1月北京大学人民医院44例急性B淋巴细胞白血病患者的133份骨髓标本进行多参数残留白血病细胞（MRD）检测。29例患者至少检测2次。结果CD45^-和CD45dim是移植后B-ALL患者最常见的LAIP，占36％，其他常见的LAIP表达依次为CD34st，CD10dim，CD10st。LAIP与发病不一致或两次检测不一致的6例患者中无一例复发，与LAIP阴性组复发率差异无统计学意义，余下的LAIP阳性组复发率（5／9）明显高于LAIP阴性组的复发率（1／14）（P=0．018）。6例复发患者中5例均在复发前1—2个月内检测到LAIP。5例患者发生Ⅱ～Ⅳ度急性移植物抗宿主病，2例患者经过注射白介素-2后观察到LAIP由阳性转为阴性。1例复发患者在供者淋巴细胞输注（DLI）后获得完全缓解。结论与初诊B．ALL相似，CD45^-和CD45dim是移植后最常见的LAIP。移植后LAIP阳性受到移植物抗白血病和免疫治疗的影响可以转阴。移植后早期单次LAIP阳性不一定预测复发，连续检测2次LAIP阳性表达一致对预测复发更有意义。

Objective To explore initially the clinical significance of leukemia-associated immunophenotypes detected by 4 color flow cytometry after hemapoietic stem cell transplantation in adult and childhood B lineage acute lymphoblastic leukemia. Methods LAIP was detected and followed up by using two panels of 4 color antibodies, mainly CD34/CD10/ CD45/CD19,in 133 bone marrow specimens of 44 patients from Jan. 2005 to Jan. 2007. Totally 29 patients were detected at least twice. Results The proportion of CD45 under-expressed or negative as a LAIP marker was the highest in patients after HSCT,being 36%. The other common LAIP included CD34st, CD10dim, CD10st in order. The relapse rate of patients whose LAIP disagreed with diagnosis LAIP or twice LAIP were different at all was 0（0/6） ,and it was not statistically significant, compared with the relapse rate of LAIP negative patients. The relapse rate of the rest LAIP positive patients （5/9） was significantly higher than LAIP negative patients （ 1/14 ） （ P = 0. 018 ）. Five in six relapsed patients were found LAIP positive during 1 - 2 months before relapse. Seven LAIP positive patients were observed to become LAIP negative after occurrence of Ⅱ - Ⅳ° aGVHD in five patients and IL-2 injection in two patients. One replaesd patient got complete remission after DLI. Conclusion The proportion of CD45 under-expressed or negative as a LAIP marker is the highest in B-ALL patients after HSCT, which is similar to the immunophenotype imformation at diagnosis. LAIP positive after HSCT can be transformed to become negative by GVHD and immunity therapy. Only once LAIP positive of early stage after HSCT may not predict relapse. Continuous twice identical LAIP positive is more valuable for the prediction of leukemia relapse.