未成熟树突状细胞表面CD1d分子在体外移植免疫中的作用☆

背景：树突状细胞具有双向免疫调节作用,成熟树突状细胞激活免疫应答,而未成熟树突状细胞则倾向诱导免疫耐受。 目的：探讨鼠CD1d分子在未成熟树突状细胞诱导移植免疫耐受中的作用,以及在此过程中细胞因子的参与机制。 方法：利用vIL-10转染的BALB/c小鼠未成熟树突状细胞在体外用粒细胞-巨噬细胞集落刺激因子基因、脂多糖刺激成熟,经抗CD1d(anti-CD1d)干预。观察培养后的细胞表型、细胞因子表达。为探明CD1d分子在异体T细胞存在下的免疫作用,进行不同实验条件的初次、再次混合淋巴细胞培养(1stMLC、2ndMLC),观察T细胞增殖、细胞因子表达。 结果与结论：Anti-CD1d的干预降低了未成熟树突状细胞增殖异体T细胞的能力,anti-CD1d干预的未成熟树突状细胞致敏异体T细胞后其免疫功能低下;anti-CD1d干预在异体T细胞存在时影响未成熟树突状细胞在功能上的成熟,主要表现在抑制白细胞介素12的分泌,加强白细胞介素10的分泌。     

白细胞介素3基因cDNA克隆与转导及其在脐血CD34+细胞中的表达

背景：单份脐血难以满足成人造血干细胞移植的要求,需对其进行体外扩增,这不仅需要较长的时间和较高的培养条件,而且容易导致干细胞自身分化,从而影响移植效果。 目的：克隆人白细胞介素3基因cDNA,构建其真核表达载体并转导脐血CD34+细胞,观察白细胞介素3的表达情况。 设计、时间及地点：细胞-基因组学体外实验,于2008年在承德医学院完成。 材料：健康成人外周血由承德市中心血站提供,脐血由承德市妇幼保健院提供,提供者对实验均知情同意。 方法：采集健康成人外周血,应用Ficoll密度梯度法分离单个核细胞,免疫磁珠法分离脐血CD34+细胞。提取白细胞介素3 mRNA,应用RT-PCT扩增白细胞介素3 cDNA,构建真核表达载体pcDNA3/IL-3。设立2组：实验组利用基因枪技术将pcDNA3/IL-3导入脐血CD34+细胞中,对照组未行转染。 主要观察指标：采用人白细胞介素3 ELISA试剂盒检测脐血CD34+细胞上清液中白细胞介素3水平。 结果：扩增的白细胞介素3基因cDNA理论上应为616 bp,实际PCR产物经琼脂糖凝胶电泳后,紫外线下可见预期大小的条带,反转录合成的cDNA完整。BamHⅠ和XbaⅠ双酶切后,电泳可见616 bp的插入片段,与白细胞介素3基因序列相同。转染第1~7天,实验组脐血CD34+细胞上清液中白细胞介素3水平明显高于未转染对照组(t=3.46,P < 0.05)。 结论：白细胞介素3基因cDNA克隆成功,并成功构建了真核表达质粒pcDNA3/IL-3,pcDNA3/IL-3能在脐血CD34+细胞中短期有效表达。     

PHA、CD3、与IL-2协同诱导PBMC过继免疫治疗恶性脑胶质瘤的实验研究

目的 提高人脑胶质瘤过继免疫治疗的效果,探索治疗脑胶质瘤的新途径。方法 用植物血凝素（PHA）、抗CD3单抗（CD3）和IL－2共同诱导人外周血单个核细胞（PBMC）,诱导,扩增新型抗胶质瘤效应细胞PHA－CD3AK细胞,并与CD3AK细胞在某些生物学方面进行了比较。结果 两组效应细胞增殖曲线均于第6天达高峰,峰值可见,PHA－CD3AK细胞＞CD3AK（P＜0．05）;PHA－CD3AK细胞扩增倍数明显高于CD3AK细胞（P＜0．05）;两组效应细胞于培养的第6、8、10天所测得的杀伤胶质瘤细胞BT325活性可见,PHA－CD3AK细胞＞CD3AK细胞（P＜0．05）。结论 PHA、CD3和IL－2具有协同增强作用,使PHA－CD3AK细胞成为较CD3AK细胞增殖能力、杀伤活性更强的免疫效应细胞、且IL－2用量减少,为胶质瘤的过继免疫治疗打下了理论基础。     

树突状细胞-细胞因子诱导杀伤细胞体外抗白血病K562细胞的效应

背景：将细胞因子诱导的杀伤细胞与树突状细胞联合起来治疗恶性肿瘤,将有助于解除部分肿瘤患者T细胞的免疫无能,从而发挥协同抗肿瘤作用。 目的：观察细胞因子诱导的杀伤细胞与树突状细胞共同培养对体外抗白血病K562细胞株的效应。 方法：分离正常人外周血单个核细胞,诱导成树突状细胞和细胞因子诱导的杀伤细胞。将树突状细胞和细胞因子诱导的杀伤细胞共同培养3 d作为效应细胞,流式细胞术检测细胞表型;以K562为靶细胞,分别以单个核细胞,细胞因子诱导的杀伤细胞,树突状细胞和树突状细胞-细胞因子诱导的杀伤细胞为效应细胞,采用MTT法进行体外杀伤实验。 结果与结论：随着效靶比的增加,各组效应细胞对K562细胞的杀伤活性也增加;同一效靶比下,各组效应细胞对K562细胞的杀伤活性不同,其中树突状细胞-细胞因子诱导的杀伤细胞对肿瘤细胞的杀伤活性最强,可达(77.88±1.57)%(P < 0.01)。提示树突状细胞-细胞因子诱导的杀伤细胞抗白血病细胞的作用显著,较单纯应用细胞因子诱导的杀伤细胞或树突状细胞具有更强的抗肿瘤活性。     

人参皂甙、CD3与IL-2协同诱导PBMC治疗恶性脑胶质瘤的实验研究

目的　提高人脑胶质瘤过继免疫治疗的效果 ,探索治疗脑胶质瘤的新途径。方法　用人参皂甙 (GS)、抗CD3单抗 (CD3 )和 IL-2共同诱导人外周血单个核细胞 (PBMC) ,诱导、扩增新型抗胶质瘤效应细胞 GS-CD3 AK细胞 ,并与 CD3 AK细胞在某些生物学方面进行了比较。结果　两组效应细胞增殖曲线均于第 6天达高峰 ,峰值可见 GS-CD3 AK细胞 >CD3 AK细胞 (P <0 .0 5 ) ;GS-CD3 AK细胞扩增倍数明显高于 CD3 AK细胞 (P <0 .0 5 ) ;两组效应细胞于培养的第 6天所测得的杀伤恶性脑胶质瘤细胞 BT3 2 5活性可见 GS-CD3 AK细胞 >CD3 AK细胞 (P <0 .0 5 )。结论　GS、CD3和 IL-2具有协同增强作用 ,使 GS-CD3 AK细胞成为较 CD3 AK细胞增殖能力、杀伤活性更强的免疫效应细胞 ,且 IL-2用量减少 ,为胶质瘤的过继免疫治疗打下了理论基础。     

血清体积分数对人细胞因子诱导杀伤细胞增殖的影响

背景：细胞因子诱导的杀伤细胞的培养多采用体积分数10%的血清,但关于血清体积分数对其生长特性的影响少有报道。 目的：观察细胞因子诱导的杀伤细胞在不同血清体积分数培养液中的增殖情况。 方法：分别配制血清体积分数为10%,20%和30% +重组人白细胞介素2等细胞因子的完全培养液培养人细胞因子诱导的杀伤细胞,使用流式细胞仪分析血清体积分数对细胞周期的影响,通过MTT法检测细胞因子诱导的杀伤细胞在不同血清体积分数培养液中的增殖,并观察细胞因子诱导的杀伤细胞的生长状态。 结果与结论：细胞因子诱导的杀伤细胞在体积分数10%血清培养液中增殖速率和增殖指数均最低,在体积分数30%血清培养液中最高,3组细胞的不同时间点的增殖速率差异均有显著性意义(P < 0.05或P < 0.01)。结果证实,体外培养的细胞因子诱导的杀伤细胞的增殖具有血清体积分数依赖性,高血清体积分数培养液的促细胞因子诱导的杀伤细胞增殖效应明显。     

利用基因芯片分析碱性成纤维细胞生长因子诱导脐血干细胞CD34+与CD133+细胞基因表达的差异*

背景：迄今为止,人们利用基因芯片对碱性成纤维细胞生长因子诱导CD34+和CD133+干细胞分化后细胞生物学性状、功能调控、基因变化及其表达差异等方面的认识尚不足,有待深入研究。 目的：利用基因芯片比较脐血CD34+和CD133+细胞基因表达的差异,并探讨碱性成纤维细胞生长因子体外诱导脐血CD34+和CD133+造血干/祖细胞分化的基因表达变化,及其对碱性成纤维细胞生长因子反应性差异。 方法：利用MiniMACS免疫磁珠法从脐静脉血单个核细胞中分离出CD34+和CD133+干/祖细胞,经含碱性成纤维细胞生长因子、B27的DMEM/F12细胞营养液培养10~15 d,提取培养前后细胞总RNA,利用Oligo GEArray®芯片和GEArray表达分析软件进行芯片数据分析。流式细胞仪检测CD34+和CD133+造血干细胞回收率。碱性成纤维细胞生长因子诱导前后CD34+、CD133+细胞形态变化。变性琼脂糖凝胶电泳测定RNA浓度和纯度。基因芯片检测结果。 结果与结论：①对20份脐血分别进行CD34+和CD133+细胞分选,分选CD34+细胞纯度为(77.52±5.06)%,回收率为(2.74±1.59)%;CD133+细胞纯度为(79.16±3.37)%,回收率为(1.12±0.94)%。②新分选出的CD34+细胞呈球形,经碱性成纤维细胞生长因子培养15 d后,多数细胞形态未发现显著变化,部分细胞出现贴壁生长,可见突起和梭形细胞。CD133+细胞呈球形,经碱性成纤维细胞生长因子培养15 d后,细胞明显扩增,由圆球形变为不规则形,部分细胞出现贴壁生长。③CD34+干细胞培养前后总RNA提取质量分别为2 236 ng和1 796 ng;CD133+干细胞培养前后总RNA提取质量分别为2 518 ng和2 191 ng。④在所检测的263个干细胞相关基因中,脐血CD133+细胞与CD34+细胞基因表达差异2倍以上的基因有10种,其中5种基因表达前者高于后者,5种基因表达前者低于后者;碱性成纤维细胞生长因子诱导培养后,CD133+细胞有32种基因表达显著高于CD34+细胞,在检测的263个基因中,未见低于CD34+细胞的基因。证实脐血中新分离的CD133+细胞和CD34+细胞基因表达仅有少数基因存在差异;CD133+细胞对碱性成纤维细胞生长因子的反应性显著强于CD34+细胞,表现为细胞周期调节、信号转导和分化等基因表达增强。     

过敏性紫癜患儿外周血树突状细胞功能变化及黄芪的体外干预

背景：树突状细胞在过敏性紫癜发病机制中可能具有重要的地位。已有报道黄芪在体内可以纠正过敏性紫癜患儿的Th1/Th2失衡,但目前关于黄芪在树突状细胞水平对过敏性紫癜病免疫功能调节的影响尚不清楚。 目的：观察过敏性紫癜患儿外周血树突状细胞功能变化及黄芪对其的影响。 设计、时间及地点：病例对照分析,于2005-10/2007-12在青岛大学医学院附属医院儿科研究所完成。 材料：急性期过敏性紫癜患儿外周静脉血28份作为过敏性紫癜组,以门诊体检的健康同龄儿童外周静脉血18份作为正常对照组。黄芪水提剂由四川百利药业有限公司提供。 方法：采用密度梯度离心法获取过敏性紫癜患儿及健康儿童外周血单个核细胞,获取的外周血单个核细胞体外经重组人粒-巨噬细胞集落刺激因子、重组人白细胞介素4、重组人肿瘤坏死因子α以诱生树突状细胞,并培养8 d,其中过敏性紫癜组又分成2组：对照组和黄芪干预组。 主要观察指标：ELISA法检测过敏性紫癜患儿及健康儿童血浆γ-干扰素和白细胞介素4水平及培养上清液中白细胞介素10,12,18水平,流式细胞仪检测树突状细胞表面CD83、CD86（B7-2）和CD80（B7-1）的表达率。 结果：过敏性紫癜患儿急性期外周血中Th1型细胞因子γ-干扰素水平减少,Th2型细胞因子白细胞介素4水平增加,γ-干扰素/白细胞介素4比值明显降低。过敏性紫癜患儿外周血单个核细胞经诱导培养的树突状细胞表面CD86表达率较正常对照组明显升高,且两组CD86表达率与血浆白细胞介素4水平皆呈显著正相关,与γ-干扰素/白细胞介素4比值皆呈显著负相关;CD80表达率明显低于正常对照组,且两组CD80表达率与血浆γ-干扰素水平及γ-干扰素/白细胞介素4比值均呈显著正相关。过敏性紫癜患儿树突状细胞分泌白细胞介素12水平低于正常对照组（P < 0.05）,而白细胞介素10,18水平均高于正常对照组（P < 0.05）,两组树突状细胞分泌白细胞介素12水平与血浆γ-干扰素水平皆呈显著正相关(P < 0.01),与γ-干扰素/白细胞介素4比值皆呈正相关(P < 0.01,P< 0 .05);白细胞介素10分泌水平与其血浆白细胞介素4水平皆呈显著正相关(P均< 0.01),与γ-干扰素/白细胞介素比值皆呈负相关(P < 0.01,P < 0.05);白细胞介素18分泌水平与其血浆白细胞介素4水平皆呈显著正相关(P均< 0.01),与γ-干扰素/白细胞介素4比值皆呈负相关(P < 0.01,P < 0.05)。黄芪干预组树突状细胞表面CD83、CD86和CD80的表达率与对照组差异不显著,树突状细胞分泌白细胞介素12水平高于对照组（P < 0.01）,白细胞介素10,18水平均低于对照组（P < 0.05,P < 0.01）。 结论：①过敏性紫癜患儿外周血树突状细胞存在明显功能紊乱,表现为CD86表达率升高、CD80降低,白细胞介素12分泌减少、白细胞介素10 和白细胞介素18增加,上述变化与Th1/Th2失衡关系密切。②黄芪主要是通过改变过敏性紫癜患儿树突状细胞分泌细胞因子的水平来调节其功能。     

脐带间充质干细胞对脐血CD34+细胞体外扩增的影响

背景：体外扩增是目前解决脐带血干细胞移植所面临的单份脐血造血干祖细胞数不足问题的主要手段。已有许多关于不同来源的间充质干细胞联合不同细胞因子支持脐血造血干祖细胞体外扩增的报道,而单独应用间充质干细胞对人脐血CD34+细胞体外扩增的报道仍很少。 目的：观察应用脐带源间充质干细胞作基质层的体外培养体系对脐血CD34+细胞体外扩增的支持作用。 设计、时间及地点：对比观察实验,于2006-03/2007-05在中国医学科学院中国协和医科大学血液学研究所、实验血液学国家重点实验室完成。 材料：经产妇知情同意,采集健康足月分娩胎儿脐带9份。 方法：应用贴壁培养的方法从正常足月出生儿脐带中分离培养间充质干细胞,通过细胞形态学、免疫表型、分化实验进行鉴定。利用免疫磁珠分离法从正常足月出生儿脐带血中分离CD34+细胞。应用3种不同培养体系进行脐血CD34+细胞的体外扩增：单独应用脐带源间充质干细胞作基质层、细胞因子培养体系和间充质干细胞联合细胞因子培养体系。 主要观察指标：应用细胞计数法、集落培养计数法和流式细胞学检测法对扩增后细胞数量、集落形成能力和免疫表型进行分析比较。RT-PCR检测间充质干细胞中细胞因子的表达情况。 结果：培养第14天后,间充质干细胞组的CD34+细胞比例明显高于细胞因子联合间充质干细胞组;CD34+细胞总数为培养前的(4.19±1.37)倍,明显高于细胞因子组。培养第7天和第14天,间充质干细胞组的CD34+CD38-细胞亚群比例均高于另两组。RT-PCR结果显示,脐带源间充质干细胞体外可表达干细胞因子和血小板生成素早期干细胞效应因子。 结论：单独应用脐带源间充质干细胞可有效地对脐血CD34+细胞进行体外扩增,更有利于保持较早期干、祖细胞的扩增。 关键词：间充质干细胞;脐带;脐血;CD34+细胞;体外扩增     

脐血CD34+细胞体外诱导分化为成熟巨核细胞及产出血小板

背景：据作者查新检索,国外尚无通过体外诱导干细胞生成具有功能的血细胞并形成产品的报道。 目的：体外诱导脐血CD34+细胞向成熟巨核细胞分化,并观察血小板产出情况。 设计、时间及地点：细胞学体外观察,于2004/2006在湘雅医院及湘雅三医院中心实验室完成。 材料：脐带来源于足月妊娠健康产妇,由湘雅医院提供。 方法：免疫磁珠法分选脐血CD34+细胞,按5×107 L-1密度接种于24孔培养板,加入含L-谷氨酰胺、铁饱和的人转铁蛋白、CaCl2、胰岛素、去离子牛血清白蛋白及重组人血小板生成素的StemPro-34无血清培养基,置于37 ℃、体积分数为0.05的CO2饱和湿度条件下向巨核细胞诱导培养14~21 d。吸取细胞培养液,离心取上清,再次离心弃上清,余下物质即为细胞培养液中比重较小的血小板样颗粒。同法分离正常富血小板血浆中的血小板。 主要观察指标：培养细胞与上清液中血小板样颗粒的形态变化、免疫组织化学染色结果、显微及超微结构观察,血小板聚集情况及CD41的表达。 结果：培养第10天,巨核细胞诱导培养体系中出现丝状物质,并有血小板样颗粒产生,第16 天达高峰;培养细胞强阳性表达血小板特异性抗原GP Ⅱb Ⅲa;光镜观察培养细胞呈成熟巨核细胞形态,但也可见幼稚巨核细胞样,巨核细胞旁可见血小板样颗粒;电镜观察培养细胞大多呈成熟巨核细胞形态,少量呈凋亡状态,上清液中血小板样颗粒与富血小板血浆中的血小板大小、超微结构基本一致,有的血小板表面光滑,有的则呈现不规则表面。上清液中血小板样颗粒与正常富血小板血浆中的血小板均能对凝血酶产生聚集反应,流式细胞仪检测两者具有同样的CD41高表达率。 结论：脐血CD34+细胞能在体外诱导生成高纯度且成熟的巨核细胞,并产出血小板。     

CD16+CD57- natural killer cells in multifocal motor neuropathy

We analyzed the CD16+CD57- lymphocyte subset, which is considered to have strong natural killer (NK) cell activity, in peripheral blood from patients with chronic immune-mediated neuropathies and patients with other neurological diseases. We found that the ratio of CD16+CD57- NK cells to total lymphocytes was increased in 4 of 6 patients with multifocal motor neuropathy (MMN) with persistent conduction block. Since the CD16 molecule is an Fc receptor for immunoglobulin G (IgG), high-dose intravenous immunoglobulin (IVIg) may interfere with CD16+CD57- NK cells via Fc receptor blockade. In addition, cyclophosphamide (Cy) is often used to suppress NK cells. Therefore, our findings may partly account for the effectiveness of IVIg or Cy, which is the current treatment of choice for MMN.     

Natural killer (NK) cells in HTLV-I-associated myelopathy/tropical spastic paraparesis-decrease in NK cell subset populations and activity in HTLV-I seropositive individuals

We examined natural killer (NK) cell activity and NK cell subset populations in 18 patients with HTLV-I associated myelopathy (HAM)/tropical spastic paraparesis (TSP), ten HTLV-I seropositive asymptomatic carriers and 20 seronegative healthy controls. The NK cell activity was significantly decreased in HAM/TSP, compared with that in controls. The percentages of NK cell subsets, such as CD16+, CD11b+, CD56+, CD16+ CD56-, CD16-CD56+, CD16+CD8-, or CD16+CD3+ cells were significantly decreased in HAM/TSP patients. Of particular interest is that the percentage of CD16+CD3+ cells, which have a wide spectrum of cytotoxic properties commonly seen in NK, lymphokine activated killer (LAK) and antibody-dependent cellular-cytotoxic (ADCC) effector cells, was significantly decreased in HAM/TSP as compared to asymptomatic carriers as well as controls. The percentage of CD16+CD3+ cells correlated inversely with the value of spontaneous proliferation of peripheral blood lymphocytes (SPP), which is a characteristic change observed in HAM/TSP.     

Apoptosis of CD4+ T and natural killer cells in Alzheimer's disease

BACKGROUND: Immunotherapy appears to be a potent treatment against Alzheimer's disease (AD), but the mechanisms underlying neural-immune interaction are still not known. METHODS: Here, we determined cell death and distribution of lymphocyte subsets of peripheral blood mononuclear cells (PBMC) in AD and aging, e.g. T (CD4+ CD3+, CD8+ CD3+), B (CD19+) and NK (CD16++CD56+) cells. RESULTS: Increased apoptosis was found in CD4+ T and NK cells in AD, while in aging all subsets were affected. The expression of anti-apoptotic Bcl2 correlated with observed cell death in T-helper and B cells irrespective of dementia. The levels of Bcl2 in T-cells were significantly increased in mild AD. Apoptosis and Bcl2 levels were also elevated in the APP (751SL)xPS1 (M146L) transgenic mouse model. CONCLUSION: The mechanisms triggering apoptosis and activation of lymphocytes in AD appear therefore to be different than those in immunosenescence and possibly bear an important biomarker to monitor immunotherapy in AD.     

Characterization of natural killer cells in paired CSF and blood samples during neuroinflammation

Natural killer (NK) cells from paired CSF and blood samples of patients with multiple sclerosis (MS), other neuroinflammatory diseases (IND), and non-inflammatory neurological diseases (NIND) were characterized using flow cytometry. NK cell frequency in CSF was overall decreased compared to blood, particularly in MS patients. In contrast to blood NK cells, during neuroinflammation, CSF NK cells display an immature phenotype with bright expression of CD56 and CD27 and reduced CX3CR1 expression. Our findings suggest that, as for central memory T cells, CSF may represent an intermediary compartment for NK cell trafficking and differentiation before entering the CNS parenchyma.     

Interferon-beta-1a treatment increases CD56 natural killer cells and CD4+CD25+ Foxp3 expression in subjects with multiple sclerosis

Disease modifying effects of interferon (IFN)-β therapy in patients with multiple sclerosis (MS) may be mediated in part through enhanced immunoregulation by the CD56^bright subpopulation of natural killer (NK) cells and by Foxp3+ (not italicized) CD4+CD25+ regulatory T cells (Treg). We found that IFN-β-1a(IM) treatment of relapsing–remitting (RR)MS subjects over 12 months significantly increased both percentage of CD56^bright NK cells and Foxp3 mRNA expression compared to baseline values, untreated RRMS subjects and healthy controls (HC). This striking enhancement of two prominent immunoregulatory pathways lends support to the idea that beneficial effects of IFN-β-1a in MS include control of pernicious autoimmunity.     

Alterations of natural killer cells in traumatic brain injury

To investigate the relationship between natural killer（NK） cells and traumatic brain injury（TBI）, we tracked an established phenotype of circulating NK cells at several time points in patients with different grades of TBI. In serial peripheral blood samples, NK cells were prospectively measured by flow cytometry of CD3-CD56＋ lymphocytes. Compared to healthy controls, TBI patients had reductions in both the percentage and the absolute number of NK cells. Furthermore, the magnitude of NK cell reduction correlated with the degree of TBI severity at several time points. That is, NK cell population size was independently associated with lower Glasgow Coma Scale scores. In addition, at some time points, a positive correlation was found between the NK cell counts and Glasgow Outcome Scale scores. Our results indicate that TBI induces a reduction in the number of NK cells, and the magnitude of the reduction appears to parallel the severity of TBI.     

The effect of IgG levels on the number of natural killer cells and their Fc receptors in chronic inflammatory demyelinating polyradiculoneuropathy

Background and purpose: High‐dose intravenous immunoglobulin (IVIg) is an established treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Although Fc receptors on natural killer cells have been suggested as a target for IVIg, the pharmacological effects are not yet clarified. We hypothesize that IVIg therapy, dependent on the plasma IgG level, suppresses the cytotoxic capacity by a reduction in numbers of NK cells and their Fc receptor CD16. Patients and methods: Ten consecutive patients with CIDP in maintenance therapy with IVIg were studied before and immediately after the infusion of 0.7–2.0 g/kg IVIg. Peripheral blood mononuclear cell samples from these patients were analyzed immediately after isolation using flow cytometry and cytotoxicity assays. Results: We found that following IVIg treatment, the cytotoxic activity of NK cells in CIDP patients was suppressed, partly caused by a dose‐dependent decline in the number of circulating NK cells. In addition, a dose‐dependent blockage of CD16 occurred. Conclusions: The study implies that IVIg infusion induces a substantial decline in the number of peripheral NK cells and a suppression of NK‐cell‐mediated cytotoxicity. We propose that these impairments of the NK cells contribute to the therapeutic effect of IVIg in CIDP.