不同血小板水平儿童急性淋巴细胞白血病的临床特征及预后研究

Clinical features and prognosis of children with acute lymphoblastic leukemia and different platelet levels

摘要:

目的 探讨儿童急性淋巴细胞白血病（ALL）初诊时不同血小板水平与预后的相关性。方法 选取采用中国儿童白血病协作组-ALL 2008（CCLG-ALL 2008）方案治疗的892例初诊ALL患儿为研究对象，按初诊时血小板水平分为血小板正常组（血小板≥ 100×10⁹/L，n=263）和血小板减少组（血小板 < 100×10⁹/L，n=629）；血小板减少组又分为（50~）×10⁹/L（n=243）、（20~）×10⁹/L（n=263）、 < 20×10⁹/L（n=123）亚组。对各组患儿的性别、年龄、免疫分型、分子生物学等临床特征与无事件生存（EFS）率、总生存（OS）率的相关性进行分析。结果 血小板正常组MLL基因重排阳性、复发率低于血小板减少组（P < 0.05），血小板正常组10年预期EFS率高于血小板减少组（P < 0.05），两组10年预期OS率差异无统计学意义（P > 0.05）；剔除MLL基因重排阳性患儿，血小板正常组10年预期EFS率仍高于血小板减少组（P < 0.05），两组10年预期OS率差异仍无统计学意义（P > 0.05）。血小板 < 20×10⁹/L亚组10年预期EFS率和10年预期OS率低于血小板正常组、（50~）×10⁹/L亚组、（20~）×10⁹/L亚组（P < 0.05）；剔除MLL基因重排阳性患儿，血小板 < 20×10⁹/L亚组10年预期EFS率和10年预期OS率仍低于血小板正常组、（50~）×10⁹/L亚组、（20~）×10⁹/L亚组（P < 0.05）。结论 伴有MLL基因重排阳性的ALL患儿临床表现多为血小板减少。ALL患儿初诊时血小板水平与患儿预后相关，血小板计数正常者复发率低、预后好，血小板 < 20×10⁹/L组预后最差。

Abstract:

Objective To study the association of platelet level at diagnosis with prognosis in children with acute lymphoblastic leukemia (ALL). Methods A total of 892 children with ALL who underwent chemotherapy with the CCLG-ALL 2008 regimen were enrolled. According to the platelet count at diagnosis, these children were divided into normal platelet count group (platelet count ≥ 100×10⁹/L; n=263) and thrombocytopenia group (platelet count < 100×10⁹/L; n=629). The thrombocytopenia group was further divided into (50- < 100)×10⁹/L (n=243), (20- < 50)×10⁹/L (n=263), and < 20×10⁹/L (n=123) subgroups. The association of clinical features (sex, age, immunophenotype, and molecular biology) with event-free survival (EFS) and overall survival (OS) was analyzed. Results Compared with the thrombocytopenia group, the normal platelet count group had significantly lower positive rate of MLL gene rearrangement and recurrence rate (P < 0.05), as well as a significantly higher 10-year EFS rate (P < 0.05). There was no significant difference in 10-year OS between the two groups (P > 0.05). The normal platelet count group still had a significantly higher 10-year EFS rate than the thrombocytopenia group after the children with MLL gene rearrangement were excluded (P < 0.05), and there was still no significant difference in 10-year OS between the two groups (P > 0.05). The < 20×10⁹/L subgroup had significantly lower 10-year EFS and OS rates than the normal platelet count group, the (50- < 100)×10⁹/L subgroup, and the (20- < 50)×10⁹/L subgroup (P < 0.05). After the children with MLL gene rearrangement were excluded, the < 20×10⁹/L subgroup still had significantly lower 10-year EFS and OS rates than the normal platelet count group, the (50- < 100)×10⁹/L subgroup, and the (20- < 50)×10⁹/L subgroup (P < 0.05). Conclusions ALL children with MLL gene rearrangement often have the clinical manifestation of thrombocytopenia. Platelet level at diagnosis is associated with the prognosis of ALL children. The children with normal platelet count have a low recurrence rate and good prognosis, and those with a platelet count of < 20×10⁹/L have the worst prognosis.