急性混合细胞白血病临床特点及免疫学表型的研究

本研究目的是分析急性混合细胞白血病（MAL）的临床特点及生物学特征,临床疗效及预后。回顾性分析了48例MAL患者,这些患者均是根据国际白血病欧洲协作组（EGIL）1995年标准而诊断的急性混合细胞白血病;同时,以同期68例急性非淋巴细胞性白血病（AML）和61例急性淋巴细胞性白血病（ALL）患者作为对照。结果表明：在同期急性白血病500例中MAL发生率为9.6%,细胞形态上往往表现为AML以M1、M2亚型为主,ALL以L2亚型为主;MAL组白细胞中位数明显高于AML组和ALL组,差别有统计学意义（P〈0.05）,MAL组肝脾淋巴结肿大例数明显高于AML组（P〈0.01）,而与ALL组相比较差别无统计学意义（P〉0.05）;MAL组以髓系和B系抗原共表达为主,占70.9%,T系和髓系共同表达的占20.8%,T系、B系和髓系均表达的占8.3%;MAL组CD34阳性率为79.2%,明显高于AML组CD34阳性率（54.4%）和ALL组CD34阳性率（52.5%）,差别均有统计学意义（P〈0.01）,提示MAL可能起源于造血干细胞;MAL组正常核型占32.1%,异常核型占67.9%,其中Ph染色体阳性率（25%）明显高于AML组Ph染色体阳性率（0%）,差别有统计学意义（P〈0.01）,而与ALL组Ph染色体阳性率（16.7%）相比较差别无统计学意义（P〉0.05）;MAL组完全缓解率（CR率）为38.1%,明显低于AML组CR率（70.8%）和ALL组CR率（72.2%）,差别均有统计学意义（P〈0.01）,MAL组疗效与CD34和Ph染色体的表达呈负相关。结论：MAL以髓系和淋巴系抗原共表达为主,它很可能源于造血干细胞,MAL较少见,常伴有较多的不良预后因素,缓解率低,预后差,因此须进一步探讨合理有效的治疗方案。

Clinical Characteristics and Immunophenotypes of Mixed-Lineage Acute Leukemia

The aim of study was to analyze the clinical,biological features,treatment outcome and prognosis of mixed-lineage acute leukemia(MAL).48 MAL patients diagnosed according to European Group of International Leukemia(EGIL)scoring system were retrospectively analyzed and the analysis results were compared with that from 68 cases of AML and 61 cases of ALL.The results showed that the incidence of MAL in acute leukemia was 9.6%.Morphologically,the subtypes of M1 and M2 were predominant in AML,while L2 in ALL.The median of white blood cell count in MAL was significantly higher than that of non-mixed-lineage cases(AML and ALL)observed during the same period(P<0.05).The incidences of enlargement of liver,spleen and lymphonodes in MAL were higher than those in AML.The difference was significant(P<0.01)and was not significant compared with those in ALL(P>0.05).Coexpression of myeloid and B lymphoid antigens in MAL patients was predominant,its rate was 70.9%.The coexpression rate of T lymphoid and myeloid antigens was 20.8%,coexpression of B,T lymphoid and myeloid antigens was 8.3%.CD34 was expressed in 79.2% of MAL cases,it was higher than those expressed in AML(54.4%)and ALL(52.5%)(P<0.01),which suggests that MAL might originate from malignant transformation of hematopoietic stem cells.Cytogenetic analysis revealed normal and abnormal karyotypes in 32.1% and 67.9% of MAL cases respectively.In MAL Ph chromosome abnormality incidence was 25% and was significantly higher than that in AML group(0%)(P<0.01),but was not statistical defference with that in ALL group(16.7%)(P>0.05).The completed remission rate of MAL was 38.1%,lower than CR rate in AML(70.8%)and ALL(72.2%)respectively(P<0.01).Treatment outcomes were negatively related to the expression of CD34 antigen and Ph chromosome.It is concluded that MAL is supposed to be originated from stem cells,coexpression of lymphoid/myeloid antigens is the major feature of MAL which accompanies many poor prognosis factors and lower CR rate.Appropriate chemotherapeutic strategy should be further searched.