系统性轻链型淀粉样变性异常浆细胞特征分析

目的:分析系统性轻链型淀粉样变性(AL)患者骨髓克隆性浆细胞数量与免疫表型特征,探索浆细胞数量、表型与疾病风险分层的联系。方法:多参数流式细胞术(MFC)检测AL患者骨髓浆细胞CD19、CD38、CD138、CD56、CD117表达情况及κ、λ轻链限制性,对照组选择同期诊断非AL的具有肾脏意义的单克隆免疫球蛋白血症(MGRS)及多发性骨髓瘤(MM)患者。收集实验室检查结果,观察AL患者临床特征,分析其单克隆浆细胞数量、免疫表型与疾病风险分层的关系。结果:共纳入AL患者119例,对照组非AL的MGRS 49例(伴单克隆免疫球蛋白沉积的增生性肾小球肾炎27例,单克隆免疫球蛋白沉积病16例,轻链沉积病3例,重链沉积病2例,轻链重链混合淀粉样变性(AHL)型1例、MM 19例。AL患者有96例(80.7%)骨髓浆细胞检测出轻链限制性,单克隆浆细胞表面CD19、CD56、CD117阳性率分别为10.4%、71.9%、46.9%。与MGRS、MM比较,AL单克隆浆细胞CD117阳性率较高(P=0.001,P0.001),浆细胞数量高于MGRS(P0.001)而低于MM(P0.001)。单克隆浆细胞CD19阴性的AL患者骨髓浆细胞数量高于CD19阳性患者(P=0.013)。结合Mayo分期系统,AL中单克隆浆细胞比例最高的为Ⅳ期0.98%(0.6%,1.37%),最低为Ⅱ期0.53%(0.29%,1.03%),两组间差异有统计学意义(P=0.033);CD117在Ⅳ期患者中阳性率高于Ⅱ、Ⅲ期患者(P=0.032,P=0.021)。结论:AL与MGRS、MM克隆性浆细胞数量及表型存在差异,AL患者Mayo分期等级高的患者克隆性浆细胞负荷及CD117阳性率较高,提示MFC检测AL患者骨髓浆细胞数量及其免疫表型特征,可辅助疾病的诊断、鉴别与疾病风险评估。     

流式细胞技术在多发性骨髓瘤诊断中的应用研究

目的:探讨CD38/138/45/SSC及CD38/56/19/45/SSC四色组合流式细胞术在多发性骨髓瘤(MM)患者诊断中的临床应用。方法:采用多参数流式细胞技术,通过CD38/CD45双抗体设门,以CD38/138/45/SSC及CD38/56/19/45/SSC四色组合检测33例确诊MM患者骨髓中的浆细胞,并进行浆细胞胞浆κ/λ的检测。结果:33例MM患者中均可检测到CD38~(++)/CD138~+/CD45~(+/-)细胞群,在该细胞群中并未找到56~-/19~+的正常浆细胞,免疫表型为45~-/56~+/19~-标本26例,占79%,45~-/56~-/19~-标本5例,占15%,45~+/56~+/19~-标本2例,占6%。对上述CD38~(++)/138~+标本进行胞浆κ/λ检测,均为单克隆瘤细胞。结论:CD38/138/45/SSC及CD38/56/19/45/SSC四色流式细胞检测能精确发现恶性变的浆细胞,在MM诊断中有重要的临床意义和诊断价值。     

116例急性髓系白血病免疫表型特点分析

目的探讨免疫表型检测对急性髓系白血病(AML)的诊断、治疗、预后的临床意义。方法回顾性分析已经确诊的116例AML患者的免疫表型结果。免疫表型检测采用流式细胞术对AML患者的骨髓样本进行多种抗原的检测。结果 116例AML白血病患者主要表达CD33(91.4%)、CD13(94%)、CD117(69%)、HLA-DR(70.7%)、CD34(71.6%),M3较少表达CD34及HLA-DR。淋系抗原在AML患者中也有阳性表达,其中CD56、CD7、CD19阳性率最高,分别为17.2%、15.5%、9.5%。伴有CD56、CD7阳性的AML患者CR率低于CD56、CD7阴性的AML患者。结论白血病免疫表型检测对AML分型诊断、预后判断有重要的指导意义。     

164例非M3型急性髓系白血病免疫表型的临床预后研究

目的 :探讨非M3型急性髓系白血病(AML)患者免疫表型的一般临床特征及预后相关性。方法 :采用CD45/侧向角散射(SSC)设门十色荧光标记流式细胞术,检测164例AML(非M3)患者抗原CD2、CD4、CD7、CD19、CD79a、CD11b、CD13、CD15、CD33、CD64、CD14、CD117、髓过氧化物酶(MPO)、人类白细胞DR抗原(HLA-DR)、CD34、CD38、CD56的表达。回顾分析不同免疫表型与年龄,性别,法国、美国和英国(FAB)分型,初诊时白细胞(WBC)、血小板(PLT)、血红蛋白(Hb)及预后的关系。结果:在164例AML(非M3)患者中髓系相关抗原表达率依次是CD13(97.6%)、CD33(97.6%)、CD117(89.6%)和MPO(84.8%);与祖相关抗原表达率依次是CD38(92.7%)、HLADR(84.8%)、CD34(63.4%),部分AML患者伴有淋系相关抗原表达,表达率最高的是CD7(30.5%),其次分别是CD56(22.0%)、CD4(18.3%)、CD19(9.8%)。CD19+、CD56+的AML患者中,M2多见,其中CD19+尤多见于M2b患者中,且CD19+、CD56+患者完全缓解(CR)率显著高于CD19-、CD56-的患者(P=0.048、P=0.038)。56.7%的AML患者具有白血病相关抗原表型(LAIP)阳性,以M2、M4、M5为主,LAIP表现为抗原跨系列表达(约87.1%,以CD7+CD117+CD34+/-、CD56+CD117+CD34+/-为主)、抗原表达量异常(约32.3%,以CD33dim为主)、抗原非同步表达(约6.5%,以CD11b同期表达为主),其中,存在抗原非同步表达的AML患者显示较短的总生存(OS)期、无病生存(DFS)期,提示其预后较差。结论:免疫表型对预测AML患者预后及指导治疗有一定的价值。     

18例急性B淋巴细胞白血病患者初诊与复发白血病相关免疫表型的改变

目的:探讨急性B淋巴细胞白血病(B-ALL)患者初诊与复发时白血病相关免疫表型的变化。方法:采用流式细胞术检测方法,对比分析18例B-ALL患者初诊与复发免疫表型,以复发时获得新的异常表型或丢失原有的异常表型,或异常表型荧光强度的增加或降低定义初诊与复发的免疫表型变化。结果:17例(94%)患者出现至少1个及以上异常表型的变化。10例(56%)患者出现新的异常表型,由初诊的表型阴性转为阳性;9例(50%)患者出现由阳性转为阴性的表型变化。9例(50%)患者部分阳性抗原复发时荧光强度显著增加,11例(61%)患者荧光强度显著降低,但仍表现为阳性。5例(28%)患者异常表型的获得与丢失同时存在。CD45为最稳定的标记,18例复发患者与初诊比较未发生显著变化。CD19在1例患者中初诊为阴性,复发时转为CD19阳性。可检测的抗原标记共计146个,其中发生表型变化的抗原标记占46%(67/146)。结论:复发与初诊的表型发生变化比较普遍,采用初诊的异常表型设门策略进行微小残留病灶检测可能会遗漏一些阳性患者,ALL患者微小残留病灶及复发诊断的监测应基于多个抗体组合和多个异常免疫模式的认定。     

多发性骨髓瘤免疫表型分析及预后

目的 :探讨多发性骨髓瘤 (MM )骨髓免疫表型的特点及外周血CD 38+ 细胞的表达。方法 :采用间接免疫荧光法对 4 1例MM患者进行免疫表型分析。结果 :①MM患者外周血及骨髓CD38+ 表达率均为 90 .2(37/ 4 1) %。②按三个不同病期分为初发期组、稳定期组及进展期组患者的骨髓细胞CD38及HLA DR阳性表达率分别为 88.9%、5 5 .6 % ;88.9%、6 6 .7% ;10 0 .0 %、4 0 .0 %。其外周血三个病期CD38+ 细胞表达率分别为88.9%、88.9%及 10 0 .0 % ,不管是外周血还是骨髓三组相比均差异无统计学意义 (P >0 .0 5 )。③按形态学分类将MM初诊患者分为成熟型和幼稚型 ,两个组CD38+ 及HLA DR阳性表达率分别为 83.3%、6 6 .7% ;10 0 .0 %、4 6 .7% ,两组相比差异无统计学意义 (P >0 .0 5 ) ;④B淋巴系统抗原在初发期、进展期中CD19、CD2 0呈部分表达 ,而在稳定期则全部消失 ;μ、κ、λ在三个组中均呈低表达 ,7例 μ、κ、λ阳性表达的病例中有 6例为骨髓瘤细胞 >6 0 %以上。结论 :CD38+ 对于诊断MM有独特意义 ,尤其结合外周血意义更大 ;B淋巴系统抗原CD19、CD2 0可能是一个预后不良因素 ,提示CD19+ 、CD2 0 + 患者预后差 ;认为骨髓中瘤细胞≥ 6 0 %对于轻链、重链的检出有价值。     

初诊多发性骨髓瘤患者CD56表达与以硼替佐米联合来那度胺为基础方案诱导治疗疗效的临床研究

分析初诊多发性骨髓瘤(MM)患者CD56表达差异与其预后的相关性,以硼替佐米联合来那度胺(VRd)为基础方案诱导治疗疗效的临床研究。回顾性分析山西医科大学第三医院血液科2015年1月—2021年8月初诊MM患者160例,分为CD56表达阳性组(CD56⁺)和CD56表达阴性组(CD56^-),比较2组临床特征及总生存期(OS);其中以VRd方案诱导治疗4个疗程的初诊MM患者共64例患者,在4个疗程后进行疗效评估及OS的分析,比较2组疗效评估的差别。CD56⁺组109例(68.1%),CD56^-组51例(31.9%);CD56^-组β2微球蛋白(β2-MG)及乳酸脱氢酶水平(LDH)较CD56⁺组更高(P=0.04,P=0.03);CD56^-组更易发生髓外病变(P<0.01);CD56⁺组患者OS更长(P=0.04);CD56^-、β2-MG≥8 mg/L是MM患者OS的独立预后不良因素(P&...     

系统检测慢性乙型肝炎患者外周血淋巴细胞免疫表型的临床意义

目的:系统研究慢性乙型肝炎患者外周血淋巴细胞免疫表型以及与临床的关系.方法:用流式细胞术测定28例慢性乙型肝炎患者外周血单个核细胞膜CD3,CD4,CD5,CD25,CD28及CD38等相关CD分子的表达情况,并与22例健康对照组比较,并分析其与HBVDNA及临床的相关性.结果:28例慢性乙型肝炎患者外周血中CD4 CD25 ,CD8 HLADR CD38 ,CD3-CD19 ,CD5-CD19 及CD19 CD38 淋巴细胞数明显高于健康对照组(t=2.37,3.71,4.10,2.31,2.17,P<0.05),而CD3-CD8 ,CD8 CD28-及CD3-CD(16 56) 淋巴细胞数明显低于健康对照组(t=3.14,3.20,2.51,P<0.05).外周血中HBVDNA含量>109copies/L的患者其CD3 CD8 ,CD8 CD28 ,CD4 CD45RA CD62L ,CD8 CD45RA CD62L 及CD4 CD38 淋巴细胞数均显著高于HBVDNA含量<109copies/L的患者,差别有统计学意义(t=2.16,2.42,2.83,3.01,2.50,P<0.01或P<0.05).结论:慢性乙型肝炎患者T、B两种淋巴细胞的活化程度均较高,NK细胞数量减少;体内HBV复制活跃的患者其T淋巴细胞活化程度较高.     

大颗粒淋巴细胞白血病的形态学和免疫表型特点

目的:探讨大颗粒淋巴细胞白血病(LGLL)的形态学和免疫表型特点。方法:回顾性分析22例LGLL患者的外周血涂片、骨髓涂片和免疫表型情况。结果:22例LGLL中T大颗粒淋巴细胞白血病(T-LGLL)14例,侵袭性NK细胞白血病(ANKL)8例。14例T-LGLL和5例ANKL的外周血涂片中可见大颗粒淋巴细胞。12例T-LGLL和7例ANKL的骨髓涂片中淋巴细胞比例增高(20.0%),11例T-LGLL和5例ANKL的骨髓涂片中可见大颗粒淋巴细胞。流式细胞学示T-LGLL中9例CD3+CD4-CD8+CD56-CD57+,5例免疫标记不典型,其中CD8-3例,CD57-2例。ANKL的免疫表型均为CD2+CD3-CD56+CD57-。6例CD7、4例CD8、1例CD5阳性。结论:LGLL中的T-LGLL和ANKL具有各自独特的形态学和免疫表型特点,二者在LGLL的诊断与鉴别诊断中具有重要的价值。     

骨髓增生异常综合征患者骨髓细胞免疫表型特点分析

目的:探讨流式细胞术(FCM)检测骨髓增生异常综合征(MDS)患者骨髓细胞免疫表型在MDS诊断及预后中的价值。方法:用FCM分析44例初诊MDS患者骨髓细胞免疫表型,分析MDS患者免疫表型的表达及分布情况;建立流式积分系统(FCSS)分析其与WHO分型及国际预后积分系统(IPSS)、WHO分型预后积分系统(WPSS)积分的相关性。结果:MDS患者骨髓细胞免疫表型存在多种异常:①骨髓原始细胞表达成熟抗原CD11b、CD15,及淋巴细胞相关抗原CD2、CD5、CD7、CD19或CD56,原始、幼稚细胞比例增高。②成熟粒细胞CD13/CD16、CD11b/CD16关系模式异常,表达CD56,中性粒细胞颗粒性减低。③单核细胞有CD56和CD34异常表达,单核细胞比例增高等。④红系Gly表达减弱,CD71表达减少,有核红细胞比例增高。⑤MDS患者骨髓细胞FCSS积分与WHO分型、IPSS积分、WPSS积分呈正相关。结论:MDS患者骨髓细胞存在多种免疫表型异常,FCM分析MDS患者骨髓细胞免疫表型异常可以为MDS的诊断和预后提供参考。     

Lack of CD56 expression on myeloma cells is not a marker for poor prognosis in patients treated by high-dose chemotherapy and is associated with translocation t(11;14)

Lack of CD56 expression was reported to be associated with a poor prognosis in multiple myeloma (MM) patients treated with conventional chemotherapy. Aim of our retrospective study was to analyse whether CD56 expression on MM cells reveals as a prognostic factor in patients treated with high-dose chemotherapy. MM cells of 99 patients prior to treatment with high-dose chemotherapy were analysed for CD56 expression by flow cytometry. Multivariable analysis of event-free survival in these patients showed no statistically significant difference between the CD56(-) (n=28) and the CD56(+) (n=71) group. The lack of CD56 expression on MM cells of these patients correlated significantly with the presence of translocation (11;14) (t(11;14)) (estimated correlation coefficient=0.655 95%, confidence interval (0.481; 0.779)). In summary, our results indicate that lack of CD56 expression on MM cells is not a prognostic marker in patients treated with high-dose chemotherapy, but is associated with t(11;14).     

High-sensitive immunophenotyping and DNA ploidy studies for the investigation of minimal residual disease in multiple myeloma.

Sensitive techniques for monitoring minimal residual disease (MRD) in multiple myeloma (MM) are needed to evaluate the effectiveness of new intensive treatment strategies. The aim of the present study was to explore the applicability and sensitivity of flow cytometry immunophenotyping and DNA ploidy studies for the investigation of residual myelomatous plasma cells (PC) in MM patients. Bone marrow (BM) samples from 61 untreated MM patients were immunophenotypically analysed with a panel of 21 monoclonal antibodies, using a high-sensitive method based on a two-step acquisition procedure through a SSC/CD38 -CD138+ 'live-gate'. Overall, in 87% of MM cases, PC displayed an aberrant phenotype at diagnosis. The most important aberrant criteria were: antigen over-expression of CD56 (62%), CD28 (16%) and CD33 (6%) and asynchronous expression of CD117 (28%), sIg (21%) and CD20 (10%). DNA aneuploidy was found in 62% of cases. The simultaneous use of these two techniques allowed the detection of aberrant/aneuploid PC in 95% of the cases. Based on dilutional experiments, the detection limit of both techniques ranged from 10(-4) to 10(-5). In 29 stem cells harvests and 19 BM samples obtained 3 months after autologous transplantation, we have investigated the presence of residual myelomatous PC; they were detected in 44% of the stem cell collections and in 61% of the BM samples obtained after transplant. The percentage of pathological PC did not significantly change during the days of harvest. In summary, the present study shows that the combined use of immunophenotyping and DNA ploidy studies is a suitable approach for MRD investigation in MM patients based on their applicability (95% of cases) and sensitivity (up to 10(-5)).     

Expression of IL-6 and IL-6 receptors by circulating clonotypic B cells in multiple myeloma: potential for autocrine and paracrine networks

OBJECTIVE: To investigate the participation of clonotypic MM B cells in the IL-6 network in patients with multiple myeloma. METHODS: CD19(+) B cells from 45 patients with multiple myeloma and from 18 healthy donors were sorted and their expression of IL-6, IL-6 receptor (CD126) characterized by flow cytometry, in situ RT-PCR, and ELISA measurement of IL-6 and soluble IL-6R. Expression of CD31 was detected by flow cytometry. RESULTS: Interleukin-6 (IL-6) is a pleiotropic cytokine often overexpressed in multiple myeloma (MM). IL-6 induces growth and inhibits apoptosis of MM plasma cells, and upregulates the activity of osteoclasts. MM plasma cells, the most mature component of the MM clone, secrete IL-6 and induce IL-6 production from other cell types. However, the MM clone also includes circulating clonotypic B lymphocytes. Using ELISA and in situ RT-PCR we demonstrate here that, unlike the healthy control B cells, MM B cells express IL-6 mRNA and secrete IL-6 protein. In vitro, MM B cells were the major producers of IL-6 in peripheral blood mononuclear cells. On average, 50% of MM B cells express the IL-6 receptor (IL-6R, CD126), suggestive of autocrine stimulation. They also express CD31, potentially facilitating their paracrine interactions with osteoclast precursors. CONCLUSION: Secretion of IL-6 by circulating clonotypic B cells in MM may contribute to the autocrine and paracrine cytokine networks that maintain the malignant clone and are responsible for disruption of normal bone metabolism in this incurable disease.     

Increased expression of non-functional killer inhibitory receptor CD94 in CD8+ cells of myeloma patients

Different MHC class I-specific killer inhibitory receptors (KIRs) are expressed in vivo by a minor fraction of activated memory CD8+ cells. It has been postulated that KIRs may 'fine-tune' specific responses by altering their threshold of activation by the TCR-CD3 complex. We have previously shown that, in multiple myeloma (MM) patients, a large fraction of peripheral blood CD8+ cells display the phenotype of chronically activated memory T cells (CD38+, HLA-DR+, CD25-, CD45R0+, CD28-). We investigated the expression of KIRs on MM T cells and determined their possible influence on cytolytic responses elicited via the CD3-TCR complex. The expression of CD94, a molecule that is part of a heterodimeric KIR recognizing the non-classical MHC surface HLA-E molecule, was almost threefold higher in MM T cells than in age-matched normal control subjects (P < 0.0001). CD94 expression was preferentially confined to CD8+ cells but not restricted to activated (HLA-DR+) and/or memory (CD45R0+) T cells. Unlike normal T cells, in which CD94 is assembled with glycoproteins of the NKG2 family to form functional receptors with activating or inhibitory properties, most CD94+ MM T cells were devoid of both the NKG2-A and NKG2-C glycoproteins detected in the inhibitory or activating form respectively. CD94 blockade did not significantly affect either T-cell proliferation or cytotoxic T-lymphocyte generation induced by the myeloma-derived cell lines NCI and RPMI 8226. Similarly, the cytolytic activity induced by direct anti-CD3-mediated targeting of MM T cells to FCR+ P815 target cells was unaffected by the addition of anti-CD94 and/or anti-NKG2-A/C monoclonal antibodies (mAbs). These data indicate that the large majority of MM CD8+ cells do not express a functional CD94 receptor. Thus, their ability to 'fine-tune' an appropriate immune response against tumour cells can be impaired.     

Signalling molecules and cytokine production in T cells of multiple myeloma-increased abnormalities with advancing stage

T-cell immune dysfunction in patients with malignant tumours has been attributed to the altered expression of components of the T-cell receptor (TCR)/CD3 complex and their associated intracellular protein tyrosine kinases. In this study, four-colour flow cytometry was applied to study the surface bound molecules TCRalphabeta, CD28, CD152 and CD154 involved in T-cell signalling and the signal transduction molecules CD3zeta, p56lck, p59fyn, ZAP-70 and phosphatidyl-inositol-3 kinase (PI3-k) as well as the intracellular cytokines interferon-gamma (IFN-gamma), interleukin (IL)-4 and IL-2 as a functional read-out of non-stimulated and superantigen (staphylococcus enterotoxin B)-stimulated blood T cells of multiple myeloma (MM) patients at different stages of the disease. Multiple abnormalities were demonstrated in the CD4 and CD8 populations, both under non-stimulated and superantigen-stimulated conditions. There was a marked reduction, particular in advanced stage MM, in the proportion of CD4 and CD8 cells expressing CD28, CD152, CD3zeta, p56lck, ZAP-70 and PI3-k. The level of intracellular T-cell cytokines (IFN-gamma, IL-2 and IL-4) was normal or increased in non-stimulated cells but activation-induced cytokine production was impaired. These results illustrated profound and multiple T-cell signalling defects, from the surface and down-stream, consistent with involvement of a master T-cell function, especially in advanced stage MM. These data should be taken into consideration when developing immune-based therapeutic approaches and when applying new emerging technologies that aim to restore T-cell functions.     

Expression of CD28 and CD40 in human myeloma cells: a comparative study with normal plasma cells

CD28 and CD40 are important activation pathways for T and B lymphocytes, respectively. The aim of this study was to determine the phenotype of plasma cells (PCs) and the expression of these two molecules, CD28 and CD40. Therefore, we have compared their expression on normal PCs from bone marrows and tonsils with that of freshly explanted malignant PCs from 31 patients with multiple myeloma (MM) and those from 12 human myeloma cell lines. For this purpose, we first described a new approach to identify plasma cells in bone marrow using two-color immunofluorescence analysis with anti-CD38 and B-B4 antibodies. B-B4 specifically recognizes all PC; all B-B4 cells are located within the CD38 bright fraction and vice versa. CD19 and CD56 expression, which was previously shown to discriminate normal from malignant PCs, was also evaluated. In the current report, we show that normal PCs express CD19, CD40, and CD56 (weakly as a subset) and lack CD28. Regardless of whether they express CD19, CD56 is clearly upregulated during the medullary chronic and accelerated phases of MM, but is absent in patients with extramedullary involvement. Although the level of CD40 expression is variable, only patients in accelerated phases expressed high CD40 levels. Finally, whereas CD28 was negative in chronic phase (as in normal PCs), it was expressed in 63% of the patients in accelerated phases and 100% of cell lines. Our data strongly suggest that both disease activity and medullary homing (or not) are correlated with the expression of CD19, CD40, CD28, and CD56 on human myeloma cells.     

多发性骨髓瘤黏附分子CD11 a、CD49d 的表达特点及临床意义

目的研究多发性骨髓瘤(MM)患者骨髓单个核细胞黏附分子CD11a、CD49d的表达,并探讨其发病机制.方法用流式细胞仪检测CD11a、CD49d在MM组及对照组2组骨髓标本单个核细胞表达的平均荧光强度和荧光阳性细胞百分率.结果MM患者骨髓单个核细胞CD49d的表达荧光强度较对照组增强(P＜0.05);CD11a的表达阳性细胞百分率及荧光强度均较对照组增强(P＜0.05,P＜0.01);进展期表达较平台期明显增强(P＜0.05,P＜0.01).结论MM单个核细胞表面CD49d的表达增强,导致患者骨髓细胞与细胞及细胞与骨髓基质间的黏附异常,可能参与了MM的病理过程,而CD11a在MM的平稳期表达较低,进展期表达明显增强,表明CD11a在MM增殖中起作用.     

CD28-mediated regulation of multiple myeloma cell proliferation and survival

Although interactions with bone marrow stromal cells are essential for multiple myeloma (MM) cell survival, the specific molecular and cellular elements involved are largely unknown, due in large part to the complexity of the bone marrow microenvironment itself. The T-cell costimulatory receptor CD28 is also expressed on normal and malignant plasma cells, and CD28 expression in MM correlates significantly with poor prognosis and disease progression. In contrast to T cells, activation and function of CD28 in myeloma cells is largely undefined. We have found that direct activation of myeloma cell CD28 by anti-CD28 mAb alone induces activation of PI3K and NFkappaB, suppresses MM cell proliferation, and protects against serum starvation and dexamethasone (dex)-induced cell death. Coculture with dendritic cells (DCs) expressing the CD28 ligands CD80 and CD86 also elicits CD28-mediated effects on MM survival and proliferation, and DCs appear to preferentially localize within myeloma infiltrates in primary patient samples. Our findings suggest a previously undescribed myeloma/DC cell-cell interaction involving CD28 that may play an important role in myeloma cell survival within the bone marrow stroma. These data also point to CD28 as a potential therapeutic target in the treatment of MM.     

Oncolytic measles virus targets high CD46 expression on multiple myeloma cells

OBJECTIVE: Multiple myeloma (MM) is an incurable B cell malignancy and novel therapeutics are urgently needed. Live attenuated measles virus (MV) has potent oncolytic activity against MM tumor xenografts. The virus is tumor selective and preferentially targets cells that express high levels of CD46 receptors. However, CD46 levels on MM have not previously been evaluated. In this study, we investigated the potential of CD46 as a target for MM therapy and correlated surface levels of CD46 on MM cells with their susceptibility to MV-induced cytopathic effects. MATERIALS AND METHODS: CD46 expression on neoplastic plasma cells (PCs) and nonplasma cells (NPCs) from 38 MM patients was analyzed by flow cytometry and receptor numbers were quantitated using BD QuantiBRITE PE beads. RESULTS: Results showed that malignant PCs expressed significantly higher levels of CD46 receptors compared to NPCs (p < 0.0001). The mean CD46 receptor numbers on PCs and NPCs were 49,130/cell and 7,340/cell, respectively. Potent cytopathic effects of extensive intercellular fusion were observed in measles-infected PCs but not in NPCs. The extent of MV-induced cytopathic effects of cell fusion correlated with CD46 expression levels on the MM cells. Normal plasma cells do not overexpress CD46 and colony-forming assays demonstrated that MV was not cytotoxic to normal bone marrow progenitor cells. CONCLUSION: The present study establishes CD46 as a surface antigen that is expressed more abundantly on primary MM cells compared to normal hematopoietic cells of various lineages in the bone marrow, making CD46 a promising surface marker for targeted cytoreductive therapy of MM.