髓样分化因子88 L265P突变在B细胞增殖性肿瘤中的研究进展

髓样分化因子88(MYD88)是Toll样受体(TLR)信号通路中的一个关键接头分子,在肿瘤的发生、发展中起重要作用.近期研究发现在90％的华氏巨球蛋白血症和约40％的弥漫大B细胞淋巴瘤等B细胞增殖性肿瘤患者中存在功能活化的MYD88 L265P突变.由于B细胞增殖性肿瘤的不同类型都具有其独特的组织学形态、免疫组织化学、临床特点,因此MYD88 L265P在各类型B细胞增殖性肿瘤中的突变率也有所不同.文章就MYD88 L265P的突变在B细胞增殖性肿瘤中的研究进展进行综述.     

初治弥漫大B细胞淋巴瘤患者MYD88基因突变的临床特征及预后分析

目的:探讨MYD88基因突变对初治弥漫大B细胞淋巴瘤（diffuse large B-cell lymphoma,DLBCL）的临床特征及预后的影响。方法:收集2013年1月至2015年1月空军军医大学第二附属医院血液科的74例初治DLBCL患者,回顾分析MYD88突变组（MYD88mut）和MYD88野生组（MYD88wt）患者的临床特征及治疗效果。结果:74例DLBCL患者中,MYD88mut组和MYD88wt组患者性别、年龄、ECOG评分、LDH、Ann Arbor分期、结外侵犯及IPI评分比较差异无统计学意义。MYD88mut组主要为ABC亚型（75.00%）。12例MYD88mut突变均为错义突变,其中8例氨基酸改变为L265P。MYD88mut组2周期R-CHOP方案完全缓解率（complete remission,CR）为41.67%,部分缓解率(partial remission,PR)为33.33%,客观有效率(objective effective,OR)为75.00%。MYD88wt组分别为77.42%、11.29%和88.71%。2组比较,2周期CR率具有统计学差异（P=0.030 4）。生存分析结果显示,MYD88mut组及MYD88wt组患者5年OS分别为54.98%与73.53%,PFS分别为48.61%与66.54%,2组比较,OS及PFS均具有统计学差异（P=0.003 4,P=0.031 9）。结论:MYD88突变主要存在于DLBCL的ABC亚型,且MYD88突变提示其预后不良。     

IgM型多发性骨髓瘤一例并文献复习

目的 探讨IgM型多发性骨髓瘤(MM)的诊断思路及鉴别要点进行分析,寻找可靠的诊断依据.方法 报道1例IgM型MM患者的临床资料并复习相关文献.结果 患者的临床表现、骨髓形态学、 细胞遗传学及MYD88L265P突变检测是IgM型MM诊断及鉴别诊断的主要依据.结论 IgM型MM临床罕见,约占所有MM类型的0.5％,目前认为其无MYD88L265P基因突变,染色体t(11;14)改变具有高度特异性,IgM型MM总体预后较差.     

弥漫性大B细胞淋巴瘤中MYD88基因突变及其临床病理相关性分析

背景与目的：MYD88基因在弥漫性大B细胞淋巴瘤（diffuse large B-cell lymphoma,DLBCL）中有一定突变率,但其临床病理相关性目前研究报道甚少。该研究旨在分析DLBCL中MYD88基因突变的发生率及与临床病理参数的相关性。方法：收集121例DLBCL患者的临床病理资料,采用免疫组织化学法分析其免疫表型,采用PCR扩增及直接测序法检测MYD88 L265P位点突变情况,采用统计学方法分析MYD88突变与各临床病理参数的相关性。结果：121例DLBCL患者中,38例（31.4%）检测到MYD88 L265P突变。其中男性50例,女性71例,患者性别与该基因突变没有相关性（P=0.609）。年龄≥60岁组MYD88突变率为40.3%（25/62）,显著高于<60岁组（13/59,22.0%）（P=0.030）。MYD88突变主要发生在结外部位,其中最常见的是乳腺（12/13,92.3%）、男性生殖系统（10/11,90.9%）、女性生殖系统（5/6,83.3%）及中枢神经系统（4/6,66.7%）;结外DLBCL中的MYD88突变率（35/98,35.7%）显著高于结内者（2/20,10%）（P=0.024）。Non-GCB型DLBCL中MYD88突变率为39.7%（25/63）,显著高于GCB亚型（10/55,18.2%）（P=0.010）;结外DLBCL组中MYD88突变与免疫分型的相关性更加显著（P=0.003）,而结内组中两者无相关性（P=0.776）。Bcl-2蛋白阳性组（30/77,39.0%）及MYC/Bcl-2蛋白双表达组（19/46,41.3%）中MYD88突变率分别高于Bcl-2阴性组（5/40,12.5%）及非双表达组（16/70,22.9%）（P=0.003和0.034）。Ki-67增殖活性与MYD88基因突变显著相关［高增殖活性组为38.8%（33/85）,低增殖活性组为6.3%（2/32）］（P<0.001）。该基因突变与MYC蛋白及CD5表达均无相关性（P=0.581和0.759）。结论：MYD88 L265P突变好发于年龄≥60岁、non-GCB起源及特殊结外部位（如乳腺、中枢神经系统及生殖系统等）的DLBCL中,且具有较高增殖指数及MYC/Bcl-2蛋白双表达率;其预后相关性有待积累更多病例进一步分析。MYD88基因突变有望为揭示DLBCL发病机制及靶向治疗提供新的理论依据。     

弥漫大B细胞淋巴瘤MYD88 L265P突变研究进展

髓样分化因子88（myeloid differentiation factor,MYD88）是细胞质里一种可溶性衔接蛋白,属于 Toll样受体（Toll-like receptors,TLR）／白介素－1受体（interleukin-1 receptor,IL-1R）家族和死亡结构域（death domain, DD）家族成员,介导大多数 Toll 样受体、白介素－1受体、白介素－18受体细胞信号传导。近年来在多种 B 细胞肿瘤中发现有功能活化的 MYD88 L265P 基因突变,这种突变导致下游细胞信号通路的异常激活,与肿瘤发生发展密切相关。本文对 MYD88 L265P 突变在弥漫大 B 细胞淋巴瘤的发生发展、预后及治疗的作用进行了综述。     

淋巴浆细胞性淋巴瘤/华氏巨球蛋白血症10例临床病理学特征分析及MYD88基因突变检测

背景与目的：淋巴浆细胞性淋巴瘤/华氏巨球蛋白血症（lymphoplasmacytic lymphoma/Waldenström macroglobulinemia,LPL/WM）是罕见的B细胞惰性淋巴瘤,其诊断常需要与其他小B细胞性肿瘤作鉴别。本研究皆在探讨LPL/WM的临床病理学特点,并观察MYD88基因突变在此类肿瘤中的检出频率。方法：分析10例LPL/WM病例的临床资料、组织学形态和免疫组织化学表型,并以聚合酶链反应（polymerase chain reaction,PCR）扩增及直接测序法检测肿瘤标本MYD88基因的状态。结果：10例患者均为男性,中位年龄61岁。患者多表现为乏力和贫血,均有不同程度的IgM型免疫球蛋白血症和肿瘤骨髓累及。淋巴结活检标本光镜检查显示淋巴结结构部分存在,特别是可以见到开放的淋巴窦。肿瘤由数量不等的浆细胞、小淋巴细胞及浆样淋巴细胞组成。骨髓活检标本也可见到相同形态的细胞浸润。免疫组织化学染色显示,10例肿瘤细胞均呈CD20弥漫阳性并限制性表达免疫球蛋白轻链κ,6例瘤细胞表达CD23,2例部分瘤细胞表达CD5,未见病例表达CD10,Ki-67增殖指数在5%~30%之间。另外,2例LPL/WM在其病灶中尚可见到较多的IgG4阳性反应性浆细胞浸润。所有LPL/WM病例肿瘤组织均有MYD88 L265P突变检出,而对照组其他小B细胞性肿瘤均为阴性结果。结论：LPL/WM多具有典型的临床病理学形态,但偶亦可出现异常表型。MYD88 L265P作为LPL/WM的特征性遗传学特点,其检测的引入可使此类肿瘤的诊断和鉴别有更可靠的依据。     

伴两种bcl-2/IgH融合基因的脾边缘区淋巴瘤一例并文献复习

目的 探讨伴有bcl-2/IgH融合基因的脾边缘区淋巴瘤(SMZL)患者的临床特征.方法 分析1例同时伴两种bcl-2/IgH融合基因SMZL患者的临床及实验室资料,并复习相关文献.结果 与经典bcl-2/IgH融合基因阴性SMZL病例相比较,该例bcl-2/IgH融合基因阳性SMZL患者实验室资料显示外周血淋巴细胞数量显著升高,临床资料显示侵袭性高,疾病进展快,接受R-CHOP方案化疗不能够获得完全缓解.结论 bcl-2/IgH融合基因鲜见于SMZL患者,bcl-2/IgH融合基因阳性SMZL患者具有恶性度高、化疗效果差的不良临床特征.     

脾边缘区淋巴瘤伴自身免疫性溶血性贫血1例并文献复习

目的：提高对脾边缘区淋巴瘤(splenic marginal zone lymphoma,SMZL)的认识。方法：详细报告1例典型患者临床及实验室特征,并复习相关文献。结果：SMZL是一少见的原发于脾脏的低度恶性B细胞淋巴瘤。临床以脾脏明显肿大、淋巴细胞增多为特征,易浸润骨髓,可合并自身免疫疾患。肿瘤细胞表达成熟B细胞免疫表型,CD5^-、CD10^-、CD23^-、CD103^-,不表达T细胞相关分化抗原。结论：SMZL起病潜隐,进展缓慢,生存期长,容易漏诊。糖皮质激素和环孢菌素A治疗SMZL合并自身免疫性溶血性贫血(AIHA)近期疗效好,对SMZL本身也有一定治疗作用。     

华氏巨球蛋白血症研究进展

华氏巨球蛋白血症(WM)是一种少见的以血清单克隆IgM为主要特征的惰性淋巴细胞肿瘤,首发症状多为发热、体质量减轻、血细胞减少或脏器肿大等.IgM型意义未明单克隆免疫球蛋白血症(IgM MGUS)和冒烟型WM(SWM)是疾病的早期阶段.WM治愈率低,但随着对其发病机制研究的深入以及各种新药的研制,患者预后得到显著改善.研究表明90%以上WM患者存在MYD88基因突变.MYD88基因编码是一种衔接蛋白,该蛋白衔接了TLR9和白细胞介素(IL)-6R信号,进而激活核因子(NF)-κB和mTOR的活性.依布替尼(ibrutinib)是首个被批准用于治疗WM的Bruton酪氨酸激酶抑制剂,对MYD88基因突变的WM具有显著疗效.第60届美国血液学会(ASH)年会关于WM的研究涵盖了多个方面,文章主要就第60届ASH会议关于WM的最新研究进行报道.     

脾边缘区淋巴瘤一例随访16年并文献复习

 目的　探讨脾边缘区淋巴瘤（SMZL）的临床及病理学特征、诊断、治疗及预后。方法　详细报道1例随访16年的SMZL患者的临床表现、治疗效果及肿瘤原发灶和转移灶的组织形态学特点,并复习相关文献。结果　SMZL临床以脾大为特征,常累及脾门淋巴结、外周血及骨髓,可发生结内及结外转移。形态学上肿瘤细胞小到中等大小,染色质较疏松,免疫组织化学肿瘤细胞sIgM(+)、CD+20、CD+79a和bcl-2(+);CD-3、CD-5、CD-10、CD-21、CD-43和CyclinD1(-)。结论　SMZL是一种少见的原发于脾脏的低度恶性B细胞淋巴瘤,起病潜隐,进展缓慢,但可向大B细胞淋巴瘤转化。脾切除和化疗有一定疗效,但不易治愈。     

Activation of TAK1 by MYD88 L265P drives malignant B-cell Growth in non-Hodgkin lymphoma

Massively parallel sequencing analyses have revealed a common mutation within the MYD88 gene (MYD88_L265P) occurring at high frequencies in many non-Hodgkin lymphomas (NHLs) including the rare lymphoplasmacytic lymphoma, Waldenström''s macroglobulinemia (WM). Using whole-exome sequencing, Sanger sequencing and allele-specific PCR, we validate the initial studies and detect the MYD88_L265P mutation in the tumor genome of 97% of WM patients analyzed (n=39). Due to the high frequency of MYD88 mutation in WM and other NHL, and its known effects on malignant B-cell survival, therapeutic targeting of MYD88 signaling pathways may be clinically useful. However, we are lacking a thorough characterization of the role of intermediary signaling proteins on the biology of MYD88_L265P-expressing B cells. We report here that MYD88_L265P signaling is constitutively active in both WM and diffuse large B-cell lymphoma cells leading to heightened MYD88_L265P, IRAK and TRAF6 oligomerization and NF-κB activation. Furthermore, we have identified the signaling protein, TAK1, to be an essential mediator of MYD88_L265P-driven signaling, cellular proliferation and cytokine secretion in malignant B cells. Our studies highlight the biological significance of MYD88_L265P in NHL and reveal TAK1 inhibition to be a potential therapeutic strategy for the treatment of WM and other diseases characterized by MYD88_L265P.     

我国血管内大B细胞淋巴瘤的临床亚型、诊治及预后分析

目的 探讨我国血管内大B细胞淋巴瘤(intravascular large B-cell lymphoma,IVLBCL)不同亚型间临床表现、诊治及预后差异.方法 系统检索并回顾性分析我国1994—2021年文献报道的185例IVLBCL.结果 185例IVLBCL患者中共活检确诊178例,其中61.8％(81/131...     

Clinical significance of disease‐specific MYD88 mutations in circulating DNA in primary central nervous system lymphoma

Recent sequencing studies demonstrated the MYD88 L265P mutation in more than 70% of primary central nervous system lymphomas (PCNSL), and the clinical significance of this mutation has been proposed as diagnostic and prognostic markers in PCNSL. In contrast, mutational analyses using cell‐free DNAs have been reported in a variety of systemic lymphomas. To investigate how sensitively the MYD88 L265P mutation can be identified in cell‐free DNA from PCNSL patients, we carried out droplet digital PCR (ddPCR) and targeted deep sequencing (TDS) in 14 consecutive PCNSL patients from whom paired tumor‐derived DNA and cell‐free DNA was available at diagnosis. The MYD88 L265P mutation was found in tumor‐derived DNA from all 14 patients (14/14, 100%). In contrast, among 14 cell‐free DNAs evaluated by ddPCR (14/14) and TDS (13/14), the MYD88 L265P mutation was detected in eight out of 14 (ddPCR) and in 0 out of 13 (TDS) samples, implying dependence on the detection method. After chemotherapy, the MYD88 L265P mutation in cell‐free DNAs was traced in five patients; unexpectedly, the mutations disappeared after chemotherapy was given, and they remained undetectable in all patients. These observations suggest that ddPCR can sensitively detect the MYD88 L265P mutation in cell‐free DNA and could be used as non‐invasive diagnostics, but may not be applicable for monitoring minimal residual diseases in PCNSL.     

Rapid detection of the MYD88 L265P mutation for pre- and intra-operative diagnosis of primary central nervous system lymphoma

The myeloid differentiation primary response gene 88 (MYD88) L265P mutation is a disease-specific mutation of primary central nervous system lymphoma (PCNSL) among the central nervous system tumors. Accordingly, this mutation is considered a reliable diagnostic molecular marker of PCNSL. As the intra-operative diagnosis of PCNSL is sometimes difficult to achieve using histological examinations alone, intra-operative detection of the MYD88 L265P mutation could be effective for the accurate diagnosis of PCNSL. Herein, we aimed to develop a novel rapid genotyping system (GeneSoC) using real-time polymerase chain reaction (PCR) based on microfluidic thermal cycling technology. This real-time PCR system shortened the analysis time, which enabled the detection of the MYD88 L265P mutation within 15 min. Rapid detection of the MYD88 L265P mutation was performed intra-operatively using GeneSoC in 24 consecutive cases with suspected malignant brain tumors, including 10 cases with suspected PCNSL before surgery. The MYD88 L265P mutation was detected in eight cases in which tumors were pathologically diagnosed as PCNSL after the operation, while wild-type MYD88 was detected in 16 cases. Although two of the 16 cases with wild-type MYD88 were pathologically diagnosed as PCNSL after the operation, MYD88 L265P could be detected in all eight PCNSL cases harboring MYD88 L265P. The MYD88 L265P mutation could also be detected using cell-free DNA derived from the cerebrospinal fluid of two PCNSL cases. Detection of the MYD88 L265P mutation using GeneSoC might not only improve the accuracy of intra-operative diagnosis of PCNSL but also help the future pre-operative diagnosis through liquid biopsy of cerebrospinal fluid.     

Detection of L265P MYD‐88 mutation in a series of clonal B‐cell lymphocytosis of marginal zone origin (CBL‐MZ)

Clonal B‐cell lymphocytosis of marginal zone origin (CBL‐MZ) is a recently described entity characterized by the presence of clonal B cells in the blood and/or bone marrow (BM) with morphologic and immunophenotypic features consistent with marginal zone derivation in otherwise healthy individuals. CBL‐MZ is commonly associated with paraproteinemia, usually immunoglobulin M (IgM), raising diagnostic difficulties from Waldenstrom macroglobulinemia (WM). The aim of the present study was to determine the presence of MYD‐88 L265P mutation in a well‐characterized series of CBL‐MZ to identify cases that may in fact represent WM. Fifty‐three CBL‐MZ cases were retrospectively evaluated. MYD‐88 L265P mutation was determined by allele‐specific polymerase chain reaction in blood and/or BM mononuclear cells. Almost half of the CBL‐MZ cases (49%) were associated with paraproteinemia mainly of the IgM type (65%). MYD‐88 L265P mutation was identified in 10 cases (19%). These cases may truly represent WM, whereas 43 cases (81%) are still classified as CBL‐MZ. Mutated cases were all associated with paraproteinemia compared with 37% of the nonmutated ones (P < .0001). In addition, mutated cases displayed more frequently CD38 and CD25 positivity (P = .002 and P = .005, respectively). Moreover, cases without paraproteinemia presented more frequently with lymphocytosis, irrespective of the presence of the MYD‐88 mutation (P = .02). The present study demonstrates that MYD‐88 L265P mutation may represent the only sensitive marker for the differentiation of CBL‐MZ from probable WM. However, further studies are warranted to better define the biological significance of MYD‐88 L265P mutation and to clarify whether the presence of the mutation establishes WM diagnosis or that it can also be present in borderline cases associated with paraproteinemia.     

基于倾向性评分匹配法比较培美曲塞或多西他赛联合顺铂治疗Ⅳ期肺腺癌的临床疗效

目的 比较培美曲塞或多西他赛联合顺铂治疗表皮生长因子受体(epidermal growth factor receptor,EGFR)突变状态未知的Ⅳ期肺腺癌的临床疗效。方法 回顾性分析2011年1月至2015年12月贵州医科大学附属医院和贵州省肿瘤医院收治的147例Ⅳ期肺腺癌患者的临床资料。采用倾向性评分匹配法,均衡组间混杂因素后比较培美曲塞+顺铂化疗方案(PP组)与多西他赛+顺铂化疗方案(DP组)的疗效和安全性。结果 倾向性评分匹配后,PP组与DP组的客观缓解率比较差异无统计学意义(60.0% vs 60.0%, χ²<0.001,P>0.999),两组疾病控制率比较差异亦无统计学意义(86.7% vs 82.5%,χ²=0.284,P=0.594);PP组中位OS优于DP组(17.0个月 vs 9.0个月, χ² =4.411,P=0.036),中位PFS亦优于DP组(8.0个月 vs 5.0个月, χ²=4.299,P=0.038);PP组死亡风险较DP组降低52.4%(HR=0.476,95%CI:0.282~0.805,P=0.006);Ⅲ~Ⅳ级中性粒细胞减少发生率低于DP组(28.9% vs 64.4%, χ²=11.429,P=0.001)。结论 在EGFR突变状态未知的Ⅳ期肺腺癌中,培美曲塞+顺铂化疗方案较多西他赛+顺铂化疗方案的临床疗效和预后更好。     

Liquid biopsy of cerebrospinal fluid for MYD88 L265P mutation is useful for diagnosis of central nervous system lymphoma

The current standard of diagnosing central nervous system (CNS) lymphoma is stereotactic biopsy, however the procedure has a risk of surgical complication. Liquid biopsy of the CSF is a less invasive, non-surgical method that can be used for diagnosing CNS lymphoma. In this study, we established a clinically applicable protocol for determining mutations in MYD88 in the CSF of patients with CNS lymphoma. CSF was collected prior to the start of chemotherapy from 42 patients with CNS lymphoma and matched tumor specimens. Mutations in MYD88 in 33 tumor samples were identified using pyrosequencing. Using 10 ng each of cellular DNA and cell-free DNA (cfDNA) extracted from the CSF, the MYD88 L265P mutation was detected using digital PCR. The conditions to judge mutation were rigorously determined. The median Target/Total value of cases with MYD88 mutations in the tumors was 5.1% in cellular DNA and 22.0% in cfDNA. The criteria to judge mutation were then determined, with a Target/Total value of 0.25% as the cutoff. When MYD88 mutations were determined based on these criteria, the sensitivity and specificity were 92.2% and 100%, respectively, with cellular DNA; and the sensitivity and specificity were 100% with cfDNA. Therefore, the DNA yield, mutated allele fraction, and accuracy were significantly higher in cfDNA compared with that in cellular DNA. Taken together, this study highlights the importance of detecting the MYD88 L265P mutation in cfDNA of the CSF for diagnosing CNS lymphoma using digital PCR, a highly accurate and clinically applicable method.     

Concurrent Waldenstrom’s Macroglobulinemia and Myelodysplastic Syndrome with a Sequent t(10;13)(p13;q22) Translocation

Myelodysplastic syndromes (MDS) and Waldenstrom’s macroglobulinemia (WM) are rarely synchronous. Ineffective myelopoiesis/hematopoiesis with clonal unilineage or multilineage dysplasia and cytopenias characterize MDS. Despite a myeloid origin, MDS can sometimes lead to decreased production, abnormal apoptosis or dysmaturation of B cells, and the development of lymphoma. WM includes bone marrow involvement by lymphoplasmacytic lymphoma (LPL) secreting monoclonal immunoglobulin M (IgM) with somatic mutation (L265P) of myeloid differentiation primary response 88 gene (MYD88) in 80–90%, or various mutations of C-terminal domain of the C-X-C chemokine receptor type 4 (CXCR4) gene in 20–40% of cases. A unique, progressive case of concurrent MDS and WM with several somatic mutations (some unreported before) and a novel balanced reciprocal translocation between chromosomes 10 and 13 is presented below.