伴NPM1突变急性髓系白血病二代测序突变基因谱与MICM分型特征关联性分析

目的:分析伴NPM1突变(NPM1^mut)急性髓系白血病(AML)患者二代测序(NGS)法检测的突变基因谱与MICM特征间的关系,解释NPM1^mutAML的临床生物学异质性。方法:收集苏州大学附属第三医院、南京医科大学附属常州第二人民医院和浙江医院收治的成人初诊AML患者,选取NGS资料完整的NPM1^mut患者238例,采用χ²检验和非参数检验分析NGS突变基因谱与常规MICM参数间的分布关联性。结果:全部患者共检出240个NPM1突变事件,其中10个(10/240,4.2%)为错义突变,均不累及W288或W290位点。这10例错义突变事件仅见于NPM1^mut/FLT3-ITD^-者,其中9例(90%)同时合并AML亚型定义的细胞遗传学或分子学异常,且全部为低危(7例)或高危(2例)组。NPM1^mut/FLT3-ITD⁺者NPM1^mut仅为插入/缺失(indel)突变。NPM1^mut/FLT3-ITD^-者高危+低危组异常核型发生率显著高于NPM1^mut/FLT3-ITD⁺者(6.4%vs.0,P=0.031)。NPM1^mut/FLT3-ITD⁺者CD34和CD7阳性率均显著高于NPM1^mut/FLT3-ITD^-者(CD34:47.9%vs.20.6%,P<0.001;CD7:61.5%vs.29.9%,P<0.001)。Logistic多因素分析显示,FLT3-ITD独立预测CD34⁺(OR=5.29,95%CI:2.64-10.60,P<0.001)和CD7⁺(OR=3.47,95%CI:1.79-6.73,P<0.001)。Ras通路突变独立预测HLA-DR⁺(OR=4.05,95%CI:1.70-9.63,P=0.002),KRAS突变独立预测MPO^-(OR=0.18,95%CI:0.05-0.62,P=0.007)。TET2/IDH1突变独立预测CD34^-(OR=0.26,95%CI:0.11-0.62,P=0.002)、CD7^-(OR=0.30,95%CI:0.14-0.62,P=0.001)和MPO⁺(OR=3.52,95%CI:1.48-8.38,P=0.004)。DNMT3A-R882独立预测HLA-DR⁺(OR=13.41,95%CI:4.56-39.45,P<0.001)和CD7⁺(OR=3.59,95%CI:1.80-7.16,P<0.001),DNMT3A突变独立预测MPO^-(OR=0.35,95%CI:1.48-8.38,P=0.004)。结论:NPM1^mutAML共存FLT3-ITD预测CD34⁺和CD7⁺,共存Ras通路突变预测HLA-DR⁺和MPO^-,共存TET2/IDH1突变预测CD34^-、CD7^-和MPO⁺,共存DNMT3A突变预测HLA-DR⁺、CD7⁺和MPO^-,这为患者免疫表型异质性提供了部分机制解释。

Association of Next Generation Sequencing Based Genotypic Profiling with MICM Characteristics in NPM1 Mutated Acute Myeloid Leukemia

Objective:To explain the clinicobiological heterogeneity of NPM1 mutated(NPM1^mut)acute myeloid leukemia(AML)by analyzing the association between next-generation sequencing(NGS)profiles and MICM characteristics in patients with this AML subtype.Methods:Data of 238 NPM1^mut patients with available NGS information on 112 genes related to blood disease was collected,andχ² test and nonparametric test were used to analyze the distribution association between NGS-detecting mutations and conventional MICM parameters.Results:In entire NPM1^mut cohort,totaling 240 NPM1 mutation events were identified,of whom 10(10/240,4.2%)were missense mutations,which did not involve any W288 or W290 locus and were found exclusively in NPM1^mut/FLT3-ITD-group.All but one of these missense mutations(9/10,90%)were accompanied by AML subtype-defining recurrent cytogenetic or molecular abnormalities,of which 7 cases were in the low risk and 2 in the high risk.NPM1^mut occurred solely as an insertion/deletion(indel)type in the NPM1^mut/FLT3-ITD⁺ group.The incidence of favorable plus unfavorable karyotypes in NPM1^mut/FLT3-ITD^- group was higher than in NPM1^mut/FLT3-ITD⁺ group(6.4%vs.0,P=0.031).The positive rates of CD34 and CD7 in NPM1^mut/FLT3-ITD⁺ group were significantly higher than in NPM1^mut/FLT3-ITD^- group(CD34:47.9%vs.20.6%,P<0.001;CD7:61.5%vs.29.9%,P<0.001).Logistic analysis showed that FLT3-ITD independently predicted for CD34⁺ and CD7⁺odds ratio(OR)=5.29,95%CI:2.64-10.60,P<0.001;OR=3.47,95%CI:1.79-6.73,P<0.001;respectively].Ras-pathway mutations independently predicted for HLA-DR⁺(OR=4.05,95%CI:1.70-9.63,P=0.002),and KRAS mutation for MPO^-(OR=0.18,95%CI:0.05-0.62,P=0.007).TET2/IDH1 mutations independently predicted for CD34^-and CD7^-(OR=0.26,95%CI:0.11-0.62,P=0.002;OR=0.30,95%CI:0.14-0.62,P=0.001;respectively),and MPO⁺(OR=3.52,95%CI:1.48-8.38,P=0.004).DNMT3 A-RS882 independently predicted for CD7⁺and HLA-DR⁺(OR=3.59,95%CI:1.80-7.16,P<0.001;OR=13.41,95%CI:4.56-39.45,P<0.001;respectively),and DNMT3 A mutation for MPO^-(OR=0.35,95%CI:1.48-8.38,P=0.004).Conclusion:Co-existing FLT3-ITD in NPM1^mut AML independently predicts for CD34⁺ and CD7⁺,co-existing Ras-pathway mutation for HLA-DR⁺ and MPO^-,co-existing TET2/IDH1 mutation for CD34^-,CD7^-,and MPO⁺,and co-existing DNMT3 A mutation for HLA-DR⁺,CD7⁺,and MPO^-,thereby providing a new mechanism explanation for the immunophenotypic heterogeneity of these AML patients.