【目的】： 18岁以下人群中原发性血小板增多症（ET）和纤维化前期原发性骨髓纤维化（pre-PMF）发病率较低，在诊断、临床结局和治疗策略等方面存在大量未知领域。为填补这些知识空白，本研究旨在通过对包含儿童及青少年 ET 患者（CAA-ET）、儿童及青少年 pre-PMF 患者（CAA-preMF）以及成人 ET 患者的大型双向队列进行分析，明确 CAA-ET、CAA-preMF 与成人 ET 在诊断标志物、突变谱、临床结局、治疗策略等方面的差异，从而完善 CAA-ET 和 CAA-preMF 的诊断标准，构建更精准的预后评估体系，并优化针对这两类疾病的治疗方法，为临床实践提供科学依据。 【方法】： 研究构建了一个大型双向队列，其中涵盖156 例 CAA-ET 患者、13 例 CAA-preMF 患者以及349 例成人 ET 患者，全面收集患者详细临床资料与血液样本。在诊断标志物研究方面，创新性地将免疫表型异常引入，作为 CAA-ET 和 CAA-preMF 新的克隆标志物，并建立起整合驱动突变和非驱动突变检测、内源性红系集落形成阳性判断、免疫表型异常分析以及染色体畸变检测等多项指标的全面克隆标志物检测方法。同时，运用二代测序技术对患者样本进行分子生物学分析，探究 CAA-ET 与成人 ET 的突变谱差异。此外，对患者进行长期随访，记录血栓等并发症发生情况、疾病进展情况，对比预期与实际治疗方案的差异，分析不同疾病类型的无进展生存期和疾病进展速度。 【结果】： 研究建立了包含多种指标的全面克隆标志物检测方法，证实免疫表型异常可作为 CAA-ET 和 CAA-preMF 重要的克隆标志物，为疾病诊断开辟新路径。二代测序结果显示，CAA-ET 与成人 ET 的突变谱存在显著差异，驱动突变分布呈现明显年龄相关趋势，有助于深入理解不同年龄段的发病机制差异。在临床结局方面，CAA-ET 患者静脉血栓发生率较高，JAK2 V617F 突变是血栓发生的潜在危险因素（P=0.016），免疫表型异常则被确定为疾病进展的危险因素（P=0.001）。治疗与预后方面，预期治疗方案与实际治疗实践存在显著差异，表明临床治疗有改进空间；CAA-preMF 较 CAA-ET 的无进展生存期更短（P<0.001），疾病进展速度更快（P=0.019），本研究为完善不同疾病类型的预后评估和治疗策略制定提供了关键参考。​ 【结论】： 本研究通过对CAA-ET、CAA-preMF和成人 ET 患者的大型双向队列分析，揭示了三者在诊断标志物、突变谱、临床结局及治疗策略等方面的显著差异。创新性地将免疫表型异常引入作为 CAA-ET 和 CAA-preMF 新的克隆标志物，并建立全面的克隆标志物检测方法，完善了疾病诊断标准。二代测序证实 CAA-ET 与成人 ET 突变谱的差异及驱动突变的年龄相关趋势，为探索发病机制提供新视角。明确 JAK2 V617F 突变、免疫表型异常分别是 CAA-ET 血栓发生和疾病进展的危险因素，指出预期与实际治疗方案间的差异，以及 CAA-preMF 更差的预后情况。研究成果为 CAA-ET 和 CAA-preMF 的精准诊断、预后评估和个性化治疗提供了坚实的科学依据，对推动相关疾病临床诊疗水平的提升具有重要意义。

【Objectives】 :
The incidence of essential thrombocythemia (ET) and pre-fibrotic primary myelofibrosis (pre-PMF) is relatively low among people under 18 years old, and there are many unknown areas in terms of diagnosis, clinical outcomes and treatment strategies. To fill these knowledge gaps, this study aims to analyze a large bidirectional cohort including children and adolescent ET patients (CAA-ET), children and adolescent pre-PMF patients (CAA-preMF), and adult ET patients. Clarify the differences between CAA-ET, CAA-preMF and adult ET in terms of diagnostic markers, mutation profiles, clinical outcomes, treatment strategies, etc., so as to improve the diagnostic criteria of CAA-ET and CAA-preMF, construct a more accurate prognosis evaluation system, and optimize the treatment methods for these two types of diseases. Provide a scientific basis for clinical practice.
【Methods】 :
The study constructed a large bidirectional cohort, which included 156 patients with CAA-ET, 13 patients with CAA-preMF, and 349 adult patients with ET. Detailed clinical data and blood samples of the patients were comprehensively collected. In the research of diagnostic markers, immunophenotypic abnormalities were innovatively introduced as new clonal markers for CAA-ET and CAA-PreMF. And a comprehensive clonal marker detection method integrating multiple indicators such as driver mutation and non-driver mutation detection, positive judgment of endogenous erythroid colony formation, immunophenotypic anomaly analysis, and chromosomal aberration detection has been established. Meanwhile, the second-generation sequencing technology was used to conduct molecular biological analysis on the patient samples to explore the differences in mutation profiles between CAA-ET and adult ET. In addition, long-term follow-up was conducted for the patients to record the occurrence of complications such as thrombosis and the progression of the disease. The differences between the expected and actual treatment plans were compared, and the progression-free survival and disease progression rate of different disease types were analyzed.
【Results】 :
The research successfully established a comprehensive clonal marker detection method including multiple indicators, confirming that abnormal immunophenotypes can serve as important clonal markers for CAA-ET and CAA-preMF, opening up a new path for disease diagnosis. The results of second-generation sequencing showed that there were significant differences in the mutation spectra between CAA-ET and adult ET, and the distribution of driver mutations showed an obvious age-related trend, which was helpful for a deeper understanding of the differences in pathogenesis among different age groups. In terms of clinical outcomes, the incidence of venous thrombosis was relatively high in patients with CAA-ET. The JAK2 V617F mutation was a potential risk factor for the occurrence of thrombosis (P=0.016), while abnormal immunophenotypes were identified as risk factors for disease progression (P=0.001). In terms of treatment and prognosis, there are significant differences between the expected treatment plan and the actual treatment practice, indicating that there is room for improvement in clinical treatment. The progression-free survival period of CAA-preMF was shorter than that of CAA-ET (P<0.001), and the disease progression rate was faster (P=0.019), providing a key reference for prognosis assessment and treatment strategy formulation of different disease types. ​
【Conclusions】 :
This study, through a large-scale bidirectional cohort analysis of children and adolescents with essential thrombocythemia (CAA-ET), children and adolescents with prefibrotic primary myelofibrosis (CAA-preMF), and adult ET patients, successfully revealed significant differences among the three in terms of diagnostic markers, mutation profiles, clinical outcomes, and treatment strategies. Innovatively, immunophenotypic abnormalities were introduced as new clonal markers for CAA-ET and CAA-preMF, and a comprehensive detection method for clonal markers was established, improving the diagnostic criteria for diseases. Second-generation sequencing confirmed the differences in the mutation profiles of CAA-ET and adult ET and the age-related trends of driver mutations, providing a new perspective for exploring the pathogenesis. It is clear that JAK2 V617F mutation and abnormal immunophenotype are respectively the risk factors for the occurrence of CAA-ET thrombosis and disease progression. The differences between expected and actual treatment regimens are pointed out, as well as the worse prognosis of CAA-preMF. The research results provide a solid scientific basis for the precise diagnosis, prognosis assessment and personalized treatment of CAA-ET and CAA-preMF, which is of great significance for promoting the improvement of the clinical diagnosis and treatment level of related diseases.