Objective: To investigate the clinical, genetic, and clonality related aspects of individuals with Richter transformation (RT) . Methods: From January 2019 to December 2021, 18 RT patients with diagnoses at the First Affiliated Hospital of Nanjing Medical University (Pukou CLL center) were retrospectively examined. The immunoglobin heavy variable (IGHV) gene usage and IGHV-D-J rearrangement pattern of diagnosed CLL/SLL and transformed diffuse large B-cell lymphoma (DLBCL) were compared to determine the clonality relatedness. To investigate the risk factors of RT, Clinical and laboratory data from patients with newly diagnosed CLL/SLL and transformed DLBCL were gathered. Results: The median age of RT was 56.5 (41-75) years old. 17 patients transformed to DLBCL and 1 transformed to Hodgkin lymphoma (HL) . Of 17 individuals who had DLBCL transformation, 15 had CLL/SLL-related clonality and 2 had unrelated clonality. Next-generation sequencing (NGS) analysis of 11 paired initially diagnosed treatment-naive CLL/SLL and RT DLBCL found that EGR2、TP53 and NOTCH1 were among the most frequently mutated genes both in treatment-naive CLL/SLL and in RT DLBCL. In several cases, specific mutations were gained or lost throughout RT, indicating clonal evolution. Among 10 patients before exposure to BTK inhibitors before RT, four patients acquired BTK mutation. The aforementioned mutations should be considered high-risk variables for transformation; in addition, TP53 and EGR2 mutations could be linked to a poor prognosis following RT in patients receiving a cocktail of new medicines. Conclusion: Most RT DLBCL patients in our center are clonality related (15/17, 88.2% ) and we recommend all qualified centers to evaluate clonality relatedness of RT DLBCL patients. There was some variability in the mutational landscape between DLBCL that had undergone a transformation and initially diagnosed, treatment-naive CLL/SLL. The underlying molecular mechanism of RT needs more research.
目的： 探索Richter转化（RT）患者的克隆同源性、临床与分子生物学特征。 方法： 回顾性分析南京医科大学第一附属医院血液科（浦口慢淋中心）2019年1月至2021年12月确诊的18例RT患者慢性淋巴细胞白血病/小淋巴细胞淋巴瘤（CLL/SLL）及转化弥漫大B细胞淋巴瘤（DLBCL）的免疫球蛋白重链可变区（IGHV）基因片段使用及IGHV-D-J重排模式，鉴定患者克隆同源性。结合患者初诊及转化时的临床信息及分子检测，分析RT患者的高危因素。 结果： 18例RT患者转化时中位年龄56.5（41~75）岁。其中17例转化为DLBCL，1例转化为霍奇金淋巴瘤（HL）。17例RT DLBCL患者中，15例（88.2%）患者DLBCL与CLL/SLL克隆同源；2例（11.8%）患者与CLL/SLL克隆非同源。其中11例患者转化前未接受治疗的CLL/SLL样本与转化后DLBCL样本配对的二代测序（NGS）结果显示突变频率最高的基因均为EGR2、TP53、NOTCH1；但部分患者转化时出现上述基因突变的新获得或丢失，提示存在克隆演变；10例布鲁顿酪氨酸激酶（BTK）抑制剂治疗后转化的患者中4例出现BTK突变。上述突变可能为促进转化的高危因素；此外，TP53、EGR2突变可能为包含新药联合方案治疗RT的不良预后因素。 结论： 本中心转化DLBCL患者大多为克隆同源性转化；推荐有条件的中心开展相关检测。转化前未治CLL/SLL与转化后DLBCL组织的突变谱有一定异质性。.
Keywords: Clonality relatedness; Leukemia, lymphocytic, chronic; Richter transformation.