血小板输注无效患者血小板同种抗体及血小板特异性糖蛋白抗体表达的研究

目的 探讨血小板输注无效与血小板同种抗原或血小板特异性抗原的相关性.方法 选择65例临床确诊血小板输注无效患者作为研究对象,应用酶联免疫吸附实验(ELISA)方法检测血清、血小板洗脱液中血小板特异性抗体;应用HLA抗体特异性检测试剂盒,对组合反应性抗体(PRA)阳性的患者进行HLA抗体特异性分析;用HPA分型试剂盒检测8个血小板同种抗原系统HPA-1、2、3、4、5、6、9、15;用HLA分型试剂盒对HLA-A/B抗原进行基因分型.结果 65例患者HLA-A/B抗原,HPA-1、2、4、5、6、9、15抗原的基因频率分布与健康献血员比较差异无统计学意义.HPA-3a、3b抗原频率分别为0.65、0.35,与健康献血员比较差异有统计学意义(P＜0.05).65例患者中HLA抗体单独阳性24例(36.9%),HLA抗体和血小板特异性糖蛋白抗体共同阳性14例(21.5%);HLA抗体和血小板洗脱液特异性糖蛋白抗体共同阳性6例(9.2%),血小板洗脱液特异性糖蛋白抗体阳性13例(20%),HLA抗体、血小板特异性糖蛋白抗体及血小板洗脱液特异性糖蛋白抗体共同阳性4例(6.2%);HLA-A/B特异性抗体中,HLA-A*9抗体占全部抗体的46.2%,HLA-B*40抗体占33.6%.血清血小板特异性抗体以GPⅡb/Ⅲa为主(26.2%),其次为GP Ⅰa/Ⅱa(21.5%),血小板洗脱液中,血小板特异性抗体以GPⅡb/Ⅲa和GP Ⅰb/Ⅸ为主(41.5%).对2例患者进行了遗传学调查,发现产生的血小板特异性糖蛋白抗体和HLA抗体与父母血小板抗原及HLA抗原不相合呈密切相关.结论 血小板输注无效患者中,HLA抗体占主要地位,其次为血小板特异性糖蛋白抗体.     

自身免疫性血小板减少性紫癜相关抗体的研究

目的　探索对自身免疫性血小板减少性紫癜 (AITP)诊断特异和敏感的实验方法。方法　采用单克隆抗体特异性俘获血小板抗原技术 (MAIPA技术 )并加以改进 ,对比检测血小板洗脱液和血浆中血小板膜糖蛋白特异性抗体。结果　AITP患者血浆游离抗血小板膜糖蛋白 (GPⅡb Ⅲa、GPⅠb Ⅸ )抗体总阳性率为 38.89%(5 4例中 2 1例 ) ,洗脱血小板表面抗血小板膜糖蛋白 (GPⅡb Ⅲa、GPⅠb Ⅸ )抗体总阳性率为 6 8.5 2 %(5 4例中 37例 ) ,两者差异有显著性 (校正 χ2 =19.39,P <0 .0 0 5 )。原发AITP组血浆游离及洗脱血小板表面抗血小板糖蛋白 (GPⅡb Ⅲa、GPⅠb Ⅸ )特异性抗体总阳性率与继发性AITP组比较差异无显著性。AITP患者血小板数量与自身抗体滴度呈明显负相关。结论　MAIPA法检测血小板洗脱液中抗血小板糖蛋白抗体在AITP的诊断和治疗中具有高度特异性 ,且敏感性较血浆抗体检测显著提高。     

血小板抗体及淋巴细胞亚群检测在特发性血小板减少性紫癜中的诊断意义

目的 比较抗血小板特异性抗体、PAIgG及淋巴细胞亚群在特发性血小板减少性紫癜（ITP）及非免疫性血小板减少症中的水平,以评价其在ITP中的诊断价值.方法 用改良单克隆抗体特异性俘获血小板抗原法（MAIPA）检测患者血浆中抗血小板膜糖蛋白（GPⅡb/Ⅲa、GPⅠb和P-选择素）的特异性抗体.利用流式细胞术（FCM）检测患者外周血中PAIgG及淋巴细胞亚群.结果 ITP组MAIPA的阳性率为63.3%,非免疫性血小板减少组为阴性;PAIgG分别为73.3%、45%.淋巴细胞亚群中,ITP组CD3、CD4、CD4/CD8显著高于正常对照组,CD8、CD19则显著低于正常对照组.结论 抗血小板特异性自身抗体抗体对提高ITP的诊断有一定的实用价值,淋巴细胞亚群的变化能较好地反映ITP 的病理机制.     

血小板特异性自身抗体检测在特发性血小板减少性紫癜中的意义

目的 检测特发性血小板减少性紫癜(ITP)患者体内的血小板特异性自身抗体与临床严重程度和临床疗效间的关系. 方法 应用改良的单克隆抗体特异性俘获血小板抗原(MAIPA)法检测血小板膜糖蛋白(GPⅡ bⅢa、GPIb)特异性自身抗体. 结果 ITP组(40例),10例为单一抗GPⅡ b Ⅲa抗体阳性.6例为单一抗GPIbα抗体阳性,20例为双抗体阳性,4例为双抗体阴性.非免疫性血小板减少组与正常对照组均为阴性.抗GPⅡbⅢa抗体(b=-0.071,P<0.01)、抗GPlbα抗体(b=-0.092,P<0.01)均与采血时血小板计数呈显著负相关.治疗后,双抗体阳性组8例治疗无效,单抗体阳性组(16例)1例治疗无效(χ2=6.09,P<0.05). 结论 血小板特异性自身抗体检测对鉴别特发性和非免疫性血小板减少症有一定价值.抗体种类与临床疗效有一定关系.     

南宁地区成人及儿童ITP患者体内血小板自身抗体特异性分布的研究

目的：研究血小板膜糖蛋白特异性自身抗体在成人及儿童原发免疫性血小板减少症（ITP）患者中分布的异同。方法应用酶联免疫吸附试验（PAKAUTO 试剂盒）检测 ITP 组（83例）及非 ITP 组（58例）患者血小板自身抗体,并分析成人组ITP（46例）,儿童组 ITP（37例）的抗 GP Ⅱ b／Ⅲ a 、抗 GP Ⅰ b／Ⅸ及抗 GP Ⅰ a／Ⅱ a 自身抗体特异性分布规律。结果 ITP 组血小板自身抗体阳性率为66．27％,高于非 ITP 组的6．90％,差异有统计学意义差异有统计学意义（P＜0．05）。成人组女性 ITP 患者占60．87％,儿童组女性 ITP 患儿占64．86％,差异无统计学意义（P ＞0．05）,但两组女性发病率均高于男性,差异有统计学意义（P＜0．05）。成人组 ITP 患者血小板自身抗体阳性率为63．04％,儿童组 ITP 患儿抗体阳性率为70．27％,差异无统计学意义（P＞0．05）;且成人组与儿童组 ITP 患者血小板自身抗体特异性分布差异无统计学意义（P ＞0．05）,均以抗 GP Ⅱ b／Ⅲ a 和抗 GPⅠ b／Ⅸ抗体多见。结论血小板自身抗体检测对 ITP 诊断、鉴别诊断及治疗均有重要的参考价值,GP Ⅰ a／Ⅱ a 抗体介导的 ITP很值得深入研究。     

血小板输注无效患者血小板特异性糖蛋白抗体表达的实验研究

目的探讨血小板输注无效(PTR)患者血小板特异性糖蛋白抗体的表达情况。方法采用ELISA方法检测56名临床上确诊为PTR患者的血小板特异性糖蛋白抗体、应用PCR方法检测其血小板特异性抗原(HPA)1-6,15基因分型。结果 56名PTR患者检出血小板特异性糖蛋白抗体,8例表达阳性(占14.3%),包括血小板特异性糖蛋白GPⅡb/Ⅲa阳性7例,GPⅠa/Ⅱa阳性1例、GPⅠb/Ⅰx阳性1例、GPⅣ阳性1例。结合8例患者的抗体检测反应格局和HPA抗原基因型结果分析抗体的特异性为:4例存在抗-HPA3b、3例存在抗-HPA3a、1例存在抗-HPA5b。结论反复输血的血小板输注无效患者,应选择HPA抗原相匹配的血小板供者,以改善血小板输注效果。     

血小板糖蛋白特异性抗体在骨髓增生异常综合征患者中的表达及其意义

本研究探讨血小板糖蛋白特异性抗体在骨髓增生异常综合征（MDS）患者发病中的作用。采用改良的MAIPA法检测血浆血小板糖蛋白特异性抗体（抗GPⅡb／Ⅲa抗体和抗GPIb／Ⅸ抗体）。若患者的OD值大于正常OD值的均数＋3倍标准差则为阳性。结果表明：MDS组总阳性率为16．67％（5／30），ITP组总阳性率为46．67％（14／30），两者之间差异有显著性（P〈0．05）。结论：部分MDS患者的糖蛋白特异性抗体为阳性，这表明部分MDS患者的血小板减少与免疫因素有关；血小板糖蛋白特异性抗体所致的血小板破坏在MDS患者的血小板减少中可能具有一定作用，这为MDS患者的免疫抑制剂治疗提供了新的依据。     

流式微球技术检测血小板特异性抗体

目的建立流式微球技术检测血小板特异性自身抗体方法,并对方法学及临床应用进行初步探讨。方法用包被抗血小板膜糖蛋白(GP)Ⅰb、Ⅱb、Ⅲa、Ⅱb/Ⅲa单克隆抗体的微球捕获与血小板GP结合的特异性抗体,加入FITC标记的羊抗人IgG抗体后用流式细胞仪检测分析。结果特发性血小板减少性紫癜(ITP)组4种单抗荧光强度比值与非ITP血小板减少组和正常对照组有显著性差异(P<0.01);若将ITP组患者4种单抗荧光强度比值分别大于正常对照组上限1.37、1.24、1.48和1.19判断为阳性,则流式微球技术检测血小板特异性自身抗体的敏感性为73.2%,特异性为94.3%;4种单抗联合检测总体敏感性明显高于改良间接单抗特异的血小板抗原固定试验(MAIPA)(P<0.05),且大于各单个抗体检测敏感性。结论流式微球技术可以简便、快捷地检测血小板膜糖蛋白特异性抗体,联合检测多种自身抗体可以提高检测阳性率,对于ITP的诊治具有一定的临床价值。     

血小板输注无效患者的血小板抗体分析

目的　分析临床血小板输注无效的主要原因并寻找解决的方法。方法　应用酶联免疫吸附试验(ELISA)方法 ,对 2 2 3例临床发生血小板输注无效的病人进行血小板抗体检测和鉴定。结果　血小板抗体阳性80例 ( 3 5 .87% ) ,其中人类白细胞抗原 (HLA)抗体阳性 75例 ( 3 3 .63 % ) ,血小板特异性抗原 (HPA)抗体阳性 1例( 0 .45 % ) ,同时含有HLA和HPA抗体者 4例 ( 1.79% )。结论　引起血小板输注无效的抗体以HLA抗体为主 ;针对不同抗体 ,可采取不同方法选择血小板供者     

特发性血小板减少性紫癜患者脾脏CD5+和CD5-B细胞共同参与血小板自身抗体的产生

目的：研究慢性特发性血小板减少性紫癜（ITP）患者脾脏CD5^ B细胞水平的变化及CD5^ 和CD5^-B细胞与血小板膜糖蛋白（GP）特异性自身抗体产生的关系，以识别致病B细胞亚群。方法：应用双色流式细胞仪检测8例慢性ITP患者脾脏CD5^ B细胞水平。选择4例血浆抗GPⅡb/Ⅲa和抗GP Ⅰb/Ⅸ抗体双阳性ITP切脾患者，应用Ficoll密度梯度离心及花环形成分离法分离脾脏B淋巴细胞，继而采用镝产珠分选法分选、纯化CD5^ B细胞和CD5^-B细胞，并分别进行体外培养，应用改良MAIPA法检测血浆和细胞培养上清液的血小板特异性抗体。结果：ITP患者脾脏CD5^ B细胞水平圈晨自身免疫性疾病患者略有增高，二者之间差异无统计学意义。CD5^ B细胞水平与患者血小板计数无相关性。4例血浆抗GPⅡb/Ⅲa抗体和抗GPⅠb/Ⅸ抗体双阳性。另外1例CD5^ B细胞培养液抗GPⅡb/Ⅲa抗体阴性，抗GPⅠb/Ⅸ抗体阳性;CD5^-B细胞培养液抗GPⅡb/Ⅲa抗体和抗GPⅠb/Ⅸ抗体双阳性。结论：脾脏CD5^ 和CD5^-B细胞 均可产生血小板GP特异性自身抗体，抗体产生种类和滴度无明显差异。提示二者共同参与了ITP的发病过程。     

抗P-selectin及血小板糖蛋白Ⅱb/Ⅲa抗体检测在特发性血小板减少性紫癜与原发性干燥综合征伴血小板减少鉴别诊断中的意义

目的：探讨抗P-选择素（P-selectin）及血小板糖蛋白Ⅱb/Ⅲa（GPⅡb/Ⅲa）抗体测定在鉴别特发性血小板减少性紫癜（ITP）和原发性干燥综合征（pSS）伴血小板减少鉴别诊断中的意义。方法采用ELISA法分别测定40例ITP患者,36例pSS伴血小板减少患者及40名正常人血浆中的抗P-selectin及GPⅡb/Ⅲa抗体。结果 pSS伴血小板减少组、ITP组抗P-selectin及GPⅡb/Ⅲa抗体水平及阳性率均高于正常对照组（P＜0.01）;pSS伴血小板减少组抗P-selectin抗体水平及阳性率显著高于ITP组（P＜0.01）;而pSS伴血小板减少组抗GPⅡb/Ⅲa抗体水平及阳性率与ITP组比较差异无统计学意义（P＞0.05）。结论抗P-selectin及GPⅡb/Ⅲa抗体测定在ITP和pSS伴血小板减少鉴别诊断中有显著的临床意义。     

Platelet membrane glycoprotein IIIa contains target antigens that bind anti-platelet antibodies in immune thrombocytopenias

The precise pathogenic mechanism of platelet destruction in immune thrombocytopenias is not known, although many investigators have found that platelet-associated IgG is increased in these diseases. We report here the differentiation between specific binding of anti-platelet antibody, associated with platelet destruction, and the ubiquitous presence of nonspecific, platelet-associated IgG. Using an electrophoretic separation and antibody overlay technique, we have identified a specific membrane protein that bears target platelet antigens in immune thrombocytopenias. When posttransfusion purpura serum was studied, antibody binding to the PlA1 antigen on glycoprotein IIIa was readily distinguished from the nonspecific binding of immunoglobulin to a protein of 200,000 mol wt. After reduction of disulfide bonds, the PlA1 antigenicity was not observed, and IgG bound nonspecifically to a protein band with an apparent molecular weight of 45,000. We have also identified anti-platelet antibodies in patients with idiopathic thrombocytopenic purpura and determined their antigenic specificity. Antibodies which bind to a 100,000-mol wt protein were found in nine of thirteen patients with chronic disease. The antigens in three of these cases were studied in detail by using both reduced and nonreduced control and Glanzmann's thrombasthenic platelets. Target antigens were localized to glycoprotein IIIa, but are different from PlA1. The immune thrombocytopenic purpura antigenic system is clearly distinguished from nonspecific platelet-associated IgG. Sera from eight children with acute idiopathic thrombocytopenic purpura were also studied. In all cases, the nonspecific IgG binding to the 200,000-mol wt protein was observed. However, we were unable to demonstrate antibody binding to glycoprotein IIIa, which suggested that the acute childhood form of this disease may have a different pathogenic mechanism than that of the autoimmune chronic cases.     

血小板特异性抗体对特发性血小板减少性紫癜诊断价值的研究

本研究的目的是比较特发性血小板减少性紫癜 (ITP)、慢性再生障碍性贫血 (CAA)、恶性血液病患者及健康志愿者特异性抗体水平 ,以评价血小板特异性抗体在ITP诊断中的价值。用改良单克隆抗体特异性俘获血小板抗原 (MAIPA)技术同时检测血小板GPIb/Ⅸ、GPIIb/Ⅲa、GPⅣ、GPⅤ的特异性抗体。结果表明 :ITP组、CAA组、恶性血液病患者及健康志愿者血小板特异性抗体总阳性率分别为 6 9.99% ,10 % ,2 0 %和 0 %。ITP组与CAA组存在显著性差异 ( χ2 =2 0 .71,P <0 .0 0 5 ) ,ITP组与恶性血液肿瘤化疗组存在显著性差异 ( χ2 =12 .2 2 ,P <0 .0 0 5 )。健康志愿组无 1例阳性。结论 :多种抗体同时检测可提高敏感性 ,血小板特异性抗体对ITP是一种特异性高、敏感性强的实验室诊断指标。     

The detection methods for antiplatelet autoantibodies (phase II and phase III assay)

A variety of methods are utilized to detect antiplatelet autoantibodies nowadays, platelet-associated immunoglobulin G(PAIgG) is a phase II assay of limited value in the meaning of its sensitivity and specificity for the diagnosis of idiopathic thrombocytopenic purpura(ITP), although it has been ordered in many occasions. The newer antigen-specific assays(phase III), which can identify autoantibodies against platelet glycoprotein(GP)s, such as GP IIb/IIIa, with greater specificity but lower sensitivity are rarely performed in clinical situations in Japan. Development of novel systems to detect clinically more relevant markers, including specific antiplatelet autoantibodies, is necessary for the diagnosis of ITP.     

Platelet antibodies of the IgM class in immune thrombocytopenic purpura

The clinical course and response to therapy of patients with immune thrombocytopenic purpura (ITP) are not completely determined by the level of IgG present on the platelet surface. It is possible that antibodies of other immunoglobulin classes also play a role in platelet destruction in some of these patients. Therefore, we studied 175 patients with ITP for the presence of IgM anti-platelet antibodies using radiolabeled polyclonal or monoclonal anti-IgM. We observed that 57% of patients with clinical ITP had increased levels of IgM on their platelets, compared with normal controls and patients with thrombocytopenia who did not have ITP (less than 10%), (P less than 0.01). We obtained similar results using either radiolabeled polyclonal or monoclonal anti-IgM, reagents whose integrity was first characterized using erythrocytes coated with defined amounts of IgM antibody. Among patients with increased platelet-IgM there was a significant correlation both with the presence of increased platelet-C3 as well as the amount of platelet-C3 (P less than 0.01, r = 0.53). We demonstrated the presence of warm-reacting IgM anti-platelet antibodies in the plasma of two of these patients who were further studied. The isolated IgM fraction from these two plasmas was able to activate complement and place 3H-C3 on normal platelets. These studies demonstrate the presence of warm-reacting IgM anti-platelet antibodies in some patients with ITP. They suggest that the binding of complement to platelets by IgM antibodies may initiate platelet clearance as well as enhance the effect of IgG antibodies in ITP.     

特发性血小板减少性紫癜患者外周血共刺激分子的表达及与血小板抗体关系的临床研究

本研究检测特发性血小板减少性紫癜（ITP）患者外周血共刺激分子CD80、CD86和CD137的表达及血清血小板抗体（PAIgG）含量并探讨二者相关性及与血小板数量等疾病表现的关系,以期阐明共刺激分子在特发性血小板减少性紫癜发病及病情判断中的作用。分别应用免疫荧光法和流式细胞术检测48例ITP患者及40名正常人外周血单个核细胞（PBMNC）表面共刺激分子CD80、CD86和CD137的表达;应用双抗体夹心酶联免疫吸附法（ELISA）检测血清PAIgG含量。结果表明：ITP患者CD80、CD86和CD137的表达水平分别为（4．92±2．02）％,（8．68±4．25）％,（5．32±2．67）％,PAIgG平均含量为210±3．02ng／10^7PA,均明显高于正常对照组（2．01±0．75）％,（4．56±2．06）％,（1．37±1．25）％和20±1．13ng／10^7 PA（p〈0．01）。共刺激分子表达水平与PAIgG含量呈正相关（r=0．302,P〈0．05）,与患者血小板数量呈负相关（r=-0．369,P〈0．05）。结论：共刺激分子CD80、CD86和CD137是参与ITP发病和免疫反应的重要共刺激分子,其过度表达与ITP发病及临床病情密切相关。纠正其异常表达、调节免疫状态可能是ITP的治疗策略之一,具有重要的临床研究意义。     

特发性血小板减少性紫癜的克隆性研究

特发性血小板减少性紫癜(ITP)患者的血小板糖蛋白上存在自身抗原表位，这些抗原表位定位于糖蛋白的某些特定区域，其数量有限。在部分慢性ITP患者中，存在B淋巴细胞和(或)T淋巴细胞的克隆性扩增，其自身抗体是克隆性起源的。这些研究对于探索特异性高、毒性小的靶向性治疗和揭示其发病机制具有重要意义。本综述讨论了ITP自身抗体的克隆限制性和B淋巴细胞的克隆性扩增，ITP中T淋巴细胞的克隆性和研究ITP克隆性的意义。     

Detection of various platelet-associated immunoglobulins by flow cytometry in idiopathic thrombocytopenic purpura

BACKGROUND: In 1975, Dixson reported that anti-platelet IgG on platelets from patients with idiopathic thrombocytopenic purpura (ITP) is greater than in normal people, by determining anti-platelet antibodies directly on the platelet surface with a quantitative complement lysis-inhibition-assay. Since then, platelet-associated IgG (PAIgG) has been thought of as evidence of ITP. Although platelets from ITP patients show significantly higher PAIgG values than from normal control individuals, PAIgG is not specific for autoantibody because it increases in other than immune ITP patients. METHODS: We analyzed positive platelet percentage with various platelet-associated immunoglobulins: IgG, IgM, IgA, and total immunoglobulins, in the blood from 17 normal donors and 23 ITP patients. RESULTS: The specificity for ITP disease was better in flow cytometry than in ELISA, because, other than ITP, only aplastic anemia was positive in flow cytometry; however, various disorders (aplastic anemia, chronic lymphocytic leukemia, acute myeloid leukemia, and myelodysplastic syndrome) showed positive in ELISA. Flow cytometry methods had the same sensitivity for ITP disease as ELISA. However, it is supposed that there was no nonimmune ITP in this study because the PAIgG negative patients (n = 1) showed positive results in flow cytometry. CONCLUSION: Flow cytometry method was effective for ITP screening, especially for specificity.     

Platelet autoantibodies in immune thrombocytopenic purpura.

In summary, the search for a useful clinical laboratory diagnostic assay for the antiplatelet antibodies has been long and difficult. Measurement of platelet associated IgG (PAIgG) has been disappointing as a way to detect autoantibodies. This is primarily due to the fact that platelets normally contain IgG in their alpha granules in an amount that varies with plasma IgG levels and age of the platelets. Furthermore, the amounts of platelet associated IgG is affected by the presence of circulating immune complexes, platelet activation, and drug dependent antibodies. The newer, platelet antigen capture techniques are promising, but further testing will be needed to confirm their value to the clinician. Methods that allow incubation of patient serum or plasma with intact platelets (MAIPA and immunobead) have greater sensitivity than techniques in which the patient antibody is tested against previously isolated platelet glycoproteins. These assays are currently available in a only a limited number of platelet immunology laboratories. Platelet autoantibodies are directed against a number of glycoprotein antigens on the platelet surface. Most studies have shown that anti GPIIb/IIIa antibodies are the most common, although antibodies against GPIb/IX and other targets are frequently detected. Many patients have multiple antiplatelet antibodies circulating simultaneously. The clinical significance of antibodies with different specificity is under investigation. The precise epitopes on GPIIIa that bind antiplatelet autoantibodies have been studied to a limited extent. Some investigators report that the vast majority of platelet antigens are conformation dependent, being destroyed by treatment with EDTA (separation of GPIIb and GPIIIa) or denaturation with detergents. Others report sequence specific peptide antigens. Further investigation promises to better define the targets for platelet autoantibodies; improved clinical management of patients with ITP is the long term goal of these studies.