反复输血后血小板输注无效患者抗体阳性率、特异性及影响因素分析

目的:分析反复输血后血小板(PLT)输注无效患者PLT抗体检测阳性率、特异性及其影响因素。方法:随机选取2015-11—2017-11反复输血后PLT输注无效住院患者的血清标本80例,通过固相凝聚法检测PLT抗体,并统计人类白细胞抗原(HLA)、人类PLT抗原(HPA)及PLT同种抗体的特异性及阳性率,同时分析其与性别、年龄、输血成分、输血次数等因素的关系。结果:PLT输注无效患者的PLT同种抗体检出率为64.00%(52/80),其中同种HLA、HPA抗体阳性率分别为43.75%(35/80)、21.25%(17/80),且58.82%(10/17)HPA抗体阳性患者同时被检出HLA阳性;PLT自身抗体阳性检出率是12.50%(10/80)。男性患者的PLT抗体阳性检出率低于女性患者,但差异无统计学意义(P>0.05);不同类型输血成分中,悬浮红细胞70.00%(14/20)高于少白细胞悬浮红细胞25.00%(5/20),浓缩PLT 95.00%(19/20)高于单采PLT 70.00%(14/20)(P<0.05);PLT抗体的数量与输血次数呈正相关(P<0.01...     

多次输血患者血小板同种抗体结果观察

长期多次输血可产生血小板同种抗体，影响血小板输注效果。我们检测了１４６例多次输血患者的血小板同种抗体，其阳性率明显高于对照组，现报告如下。资料与方法：实验对象为５０例健康献血者、２２５例孕妇和１４６例多次输血者。用简易致敏红细胞血小板血清学技术行血小板同种抗体检查，试剂由上海血液中心提供。微量淋巴细胞毒试验按〔美〕国立卫生研究所（ＮＩＨ）标准方法进行，取每份患者血清与４０例随机供血者的淋巴细胞进行反应。每孔死淋巴细胞数＞６０％为阳性。结果：①血小板同种抗体：本文健康献血者、孕妇及多次输血患者的血…     

血小板同种免疫抗体与血小板输注

近年来 ,临床对血小板抗体及其引起的同种免疫反应问题非常重视 ,它不仅对提高血小板输注疗效有重要意义 ,还对诊断和预防各种免疫性血小板减少性疾病具有重要价值。1　血小板同种免疫抗体检测在输注中的重要意义由于血小板表面具有血型抗原 ,一旦不相同的抗原进入人体血液循环中就可能产生同种免疫反应 ,从而产生相应的同种抗体 ,发生血小板输注无效 (PTR)和血小板输血紫癜(PTP)。有报道反复大量输注血小板可导致 5 0 %的患者产生同种免疫抗体 [1 ] ,其中 HL A抗体占多数 ,血小板特异性抗体只占 2 .7%左右 ,虽然血小板特异性抗体发生率…     

急性白血病患者血小板无效输注的原因分析

目的：探讨急性白血病（AL）血小板输注无效的原因。方法：观察106例AL患者的263例次单采血小板输注效果并检测血小板抗体,分析讨论血小板无效输注的影响因素。结果：①AL血小板无效输注率为43．35％;②血小板抗体阳性检出率为32．32％;③血小板输注有效组与无效组的抗体阳性检出率的差异有统计学意义（P〈0．01）。④AL发热组输注无效率高于未发热组（P〈0．01）;脾脏肿大与无肿大组无效输注率差异有统计学意义（P〈0．01）。结论：引起血小板输注无效的病因复杂。血小板输注前应进行血小板抗体的筛选,避免或减少造成血小板输注无效的原因,提高血小板输注的有效率。     

配型血小板输注有效性的临床研究

目的 :探讨配型血小板输注的临床效果。方法 :对 87例需要反复输注浓缩红细胞、血小板的恶性血液病患者采用淋巴细胞毒试验 (LCT)检测 ,研究患者血小板校正增加值测定 (CCI)与LCT、血小板输注无效之间的关系。经多次血小板输注产生同种抗体的部分患者 ,给予输注补体依赖交叉配型 (CDC)相合的血小板。结果 :87例患者共输注血小板 2 16次 ,其中CCI有效率为 71% ,CCI无效率为 2 9% ;CCI有效组LCT阳性率为 7.9% ,CCI无效组LCT阳性率为 2 4 .6 % ,CCI无效组LCT阳性率与CCI有效组相比差异有显著性意义 (χ2 =10 .4 ,P <0 .0 1) ;对 17例LCT阳性而血小板输注无效的患者共进行了 4 6例次CDC交叉配型血小板输注 ,CCI无效率分别为 :配型前 6 3.4 % ,配型后 35 .7% (χ2 =8.0 3,P <0 .0 1)。结论 :在 87例患者中 ,对产生同种抗体而导致血小板输注无效的部分患者 ,采用CDC交叉配型血小板输注效果较好。     

反复输血后血小板输注无效患者抗体阳性率、特异性及影响因素分析

目的:分析反复输血后血小板(PLT)输注无效患者PLT抗体检测阳性率、特异性及其影响因素。方法:随机选取2015-11—2017-11反复输血后PLT输注无效住院患者的血清标本80例,通过固相凝聚法检测PLT抗体,并统计人类白细胞抗原(HLA)、人类PLT抗原(HPA)及PLT同种抗体的特异性及阳性率,同时分析其与性别、年龄、输血成分、输血次数等因素的关系。结果:PLT输注无效患者的PLT同种抗体检出率为64.00%(52/80),其中同种HLA、HPA抗体阳性率分别为43.75%(35/80)、21.25%(17/80),且58.82%(10/17)HPA抗体阳性患者同时被检出HLA阳性;PLT自身抗体阳性检出率是12.50%(10/80)。男性患者的PLT抗体阳性检出率低于女性患者,但差异无统计学意义(P0.05);不同类型输血成分中,悬浮红细胞70.00%(14/20)高于少白细胞悬浮红细胞25.00%(5/20),浓缩PLT 95.00%(19/20)高于单采PLT 70.00%(14/20)(P0.05);PLT抗体的数量与输血次数呈正相关(P0.01)。结论:反复输血后PLT输注无效患者以同种HLA、HPA抗体最为常见,且PLT抗体的数量与输血次数呈正相关,不同的输血成分与产生的PLT抗体有着密不可分的联系。     

新乡地区临床患者的血小板抗体检测及配型的疗效分析

目的:调查新乡地区临床反复输血和输注血小板的患者血小板抗体阳性率及血小板交叉配合性输注的输注效果。方法:设86例3次以上输血史的随机血小板输注患者为实验组,80名≤3次输血史的随机住院患者为对照组,采用固相凝集法检测实验组及对照组中患者的血小板抗体阳性率,对46例产生血小板抗体的临床患者,通过配合性输注24h后血小板计数增高指数(CCI)来观察患者血小板输注效果。结果:实验组和对照组血小板抗体阳性率分别为43.02%和11.25%,实验组明显高于对照组;临床患者输注ABO同型随机机采血小板不同输注次数相比较,≤3次、4~6次、6次以上有效率分别为70.00%、66.67%、37.14%,差异均有统计学意义(均P0.05);46例产生血小板抗体的临床患者经配合性血小板输注,计算24h后CCI、血小板回收率,输注次数≤3次、4~6次的临床患者输注效果明显高于6次以上。结论:对于≥5次输血的患者及反复血小板输注无效的患者,对其检测血小板抗体筛检,对产生血小板抗体的患者进行交叉配型,配合性输注,提高输注疗效,真正做到安全有效输血,减少血液的浪费。     

血小板输注与HLA抗体的临床意义

血小板输注与ＨＬＡ抗体的临床意义李敬兰金宗骧赵纯平杨杰坤曹金霓我们检测６６例长期输血小板的急性白血病（ＡＬ），再生障碍性贫血（ＡＡ）的同种抗体（ＨＬＡ抗体），并观察部分抗体阳性患者血小板交叉配型输血的临床效果。一、材料与方法１．观察对象、血小板来源与...     

血小板输注中抗体检测和配合试验的应用

目的：提高血小板制剂对血小板减少、尤其是血小板输注无效症（PTR）患者的输注疗效,避免宝贵血源的浪费。方法：应用单抗固相微孔板（MASPAT）法检测患者血清中的血小板抗体,进行血小板供者与患者之间的配合试验。结果：2005年6月-2007年11月对109例患者进行了血小板抗体的检测,其中42例患者检出血小板抗体（阳性率38．5％）,对含有血小板抗体的患者经适合性血小板输注后,血小板计数有明显上升。结论：MASPAT法在特异性、敏感性、重复性方面良好,操作快速、简便,判断可靠;易做到规范化,程序化,标准化;据此建立的“适合性血小板输注”对含有血小板抗体的患者是有效的,可用于临床血小板抗体的检测和配合试验。     

血液病多次输血者血小板抗体与血小板输注效果和反应的关系

血小板输注是治疗血小板减少引起的出血性疾病的重要措施，尤其是对再生障碍性贫血(AA)、白血病和肿瘤患者，在化、放疗或用抗癌药物治疗的同时，血小板输注可作为辅助疗法以防患者出现严重出血。然而反复输血可发生同种免疫反应，产生抗血小板抗体，而该抗体可影响血小板输注效果，导致血小板输注反应。我们采用简易致敏红细胞血     

肿瘤患者血小板相关抗体的检测

目的：探讨血小板相关抗体的测定方法以及肿瘤患者血小板抗体产生与临床输注效果的关系。方法：对55例反复输注血小板的肿瘤患者分别用酶联免疫法和微柱凝胶法进行人类白细胞抗原抗体检测并通过血小板校正增高指数对输注效果进行监测。结果：55例样本中用酶联免疫法筛查抗体阳性者22例,用微柱凝胶法筛出抗体阳性者14例;2种方法均未发现抗体阳性率与血小板输注次数和临床输注效果的重要相关性。结论：酶联免疫法检测的阳性率高于微柱凝胶法。肿瘤患者的临床情况复杂,血小板输注效果影响因素众多,除了血小板相关抗体外还需综合考虑,以期达到更好效果。     

Protein A Sepharose immunoadsorption can restore the efficacy of platelet concentrates in patients with Glanzmann's thrombasthenia and anti-glycoprotein IIb-IIIa antibodies

Type I Glanzmann's thrombasthenia is a rare congenital platelet function disorder, characterized by undetectable platelet membrane glycoprotein IIb-IIIa (GPIIb-IIIa). Severe bleeding is controlled by transfusion of normal platelets, leading in some cases to the occurrence of anti-GPIIb-IIIa isoantibodies, which induces a loss of transfused platelet efficacy. We used immunoadsorption on protein A Sepharose (IA-PA), which has been shown to be efficient in decreasing the titre of antibodies in several immune diseases, in three patients with Glanzmann's thrombasthenia and anti-GPIIb-IIIa isoantibodies on five different occasions. IA-PA was well tolerated with no deleterious side-effects reported. It induced a dramatic decrease of total immunoglobulin (Ig)G, including anti-GPIIb-IIIa isoantibody levels, as assessed by the monoclonal antibody-specific immobilization of platelet antigens test and the ex vivo inhibition of normal platelet aggregation induced by the patient's platelet-rich or platelet-poor plasma. Elimination of the antibody was associated with a correction of the bleeding time following platelet transfusion. IA-PA combined with platelet transfusion made it possible to control two life-threatening haemorrhages, and allowed two surgical procedures and one bone marrow transplantation to be performed safely. Our experience suggests that IA-PA, which restores the haemostatic efficacy of platelet transfusion, is a valuable therapeutic strategy in patients with Glanzmann's thrombasthenia and anti-GPIIb-IIIa isoantibodies.     

Refractoriness to platelet transfusion in acute myeloid leukemia correlated with the optical density of anti-platelet factor 4/heparin antibodies

A small number of reports have described cases of heparin-induced thrombocytopenia complicating hematological disorders with impaired platelet production. We describe the case of a 66-year-old woman with acute myeloid leukemia who exhibited unexplained refractoriness to platelet transfusion, while receiving heparin flushes, and was found to have anti-platelet factor 4 (PF4)/heparin antibodies with high optical density (OD) values (>2 units) detected by an enzyme-linked immunosorbent assay. After cessation of heparin flushes, her refractoriness to platelet transfusion resolved. We retrospectively confirmed that the OD values for anti-PF4/heparin antibodies declined gradually; refractoriness to platelet transfusion resolved when the OD values fell below 1.0 units. Given the absence of any other evident explanation for this phenomenon, and the correlation between the OD values for anti-PF4/heparin antibodies and the efficacy of platelet transfusions, we conclude that the patient’s refractoriness to platelet transfusion was most likely caused by anti-PF4/heparin antibodies that had platelet-activating properties.     

人源化抗血小板膜糖蛋白Ⅱb/Ⅲa抗体库的构建及临床价值

目的筛选出抑制血小板聚集的血小板膜糖蛋白(GP)Ⅱb/Ⅲa自身抗体,用噬菌体表面展示技术构建人源化抗血小板GPⅡb/Ⅲa单链噬菌体抗体(ScFv)库。方法用单克隆抗体特异性俘获血小板抗原(MAIPA)技术和血小板聚集试验筛选出血浆中含有抑制血小板聚集的血小板GPⅡb/Ⅲa自身抗体的特发性血小板减少性紫癜(ITP)患者。从筛选出患者的外周血淋巴细胞中提取mRNA,用RT PCR扩增出人免疫球蛋白的重链可变区(VH)和轻链可变区(VL)基因片断,用DNA linker将VH和VL连接成ScFv基因片断。用限制性内切酶SfiⅠ/NotⅠ酶切ScFv后克隆到噬菌体载体pHEN2,然后转化大肠杆菌TG1。用辅助噬菌体M13K07援救转化后的TG1,产生ScFv。结果95例慢性ITP患者中41例(43.2%)血浆中抗GPⅡb/Ⅲa自身抗体阳性,强阳性患者5例(5.3%)。2例(2.1%)明显抑制血小板聚集功能。扩增出380～400bp大小的VH和VL基因,用连接肽(Gly4Ser)3成功地连接成约780bp大小的ScFv片断。ScFv克隆到pHEN2并转化大肠杆菌TG1后,形成2.1×107个克隆。用辅助噬菌体M13K07援救TG1后产生的噬菌体抗体库滴度为1.62×1010cfu/ml。结论少数抗GPⅡb/Ⅲa自身抗体可抑制血小板聚集功能。用噬菌体表面展示技术构建了ScFv库,可用来筛选人源化抗血小板GPⅡb/ⅢaScFv。     

The role of point-of-care assessment of platelet function in predicting postoperative bleeding and transfusion requirements after coronary artery bypass grafting

Objective:

Objective platelet function assessment after cardiac surgery can predict postoperative blood loss, guide transfusion requirements and discriminate the need for surgical re-exploration. We conducted this study to assess the predictive value of point-of-care testing platelet function using the Multiplate^® device.

Methods:

Patients undergoing isolated coronary artery bypass grafting were prospectively recruited (n = 84). Group A (n = 42) patients were on anti-platelet therapy until surgery; patients in Group B (n = 42) stopped anti-platelet treatment at least 5 days preoperatively. Multiplate^® and thromboelastography (TEG) tests were performed in the perioperative period. Primary end-point was excessive bleeding (>2.5 ml/kg/h) within first 3 h postoperative. Secondary end-points included transfusion requirements, re-exploration rates, intensive care unit and in-hospital stays.

Results:

Patients in Group A had excessive bleeding (59% vs. 33%, P = 0.02), higher re-exploration rates (14% vs. 0%, P < 0.01) and higher rate of blood (41% vs. 14%, P < 0.01) and platelet (14% vs. 2%, P = 0.05) transfusions. On multivariate analysis, preoperative platelet function testing was the most significant predictor of excessive bleeding (odds ratio [OR]: 2.3, P = 0.08), need for blood (OR: 5.5, P < 0.01) and platelet transfusion (OR: 15.1, P < 0.01). Postoperative “ASPI test” best predicted the need for transfusion (sensitivity - 0.86) and excessive blood loss (sensitivity - 0.81). TEG results did not correlate well with any of these outcome measures.

Conclusions:

Peri-operative platelet functional assessment with Multiplate^® was the strongest predictor for bleeding and transfusion requirements in patients on anti-platelet therapy until the time of surgery. Study registration: ISRCTN43298975 (http://www.controlled-trials.com/ISRCTN43298975/).     

Study of a humanized inhibitory anti-platelet glycoprotein VI phage antibody from a phage antibody library

Objective: The aims of the study were to study the effect of anti-platelet glycoprotein (GP) VI auto-antibodies on platelet aggregation and use phage surface display technology to produce anti-platelet GPVI phage antibody fragment, which may be developed to inhibit platelet aggregation in the treatment of cardiovascular disease.

Methods: Plasma samples from patients with immune thrombocytopenia (ITP) were screened by monoclonal antibody immobilization of the platelet antigen assay and the platelet aggregation test for anti-platelet GPVI auto-antibody with an inhibitory effect. The humanized anti-platelet GPVI phage antibody was produced by phage surface display technology. The function of the phage antibody fragment against platelet aggregation was examined by the platelet aggregation test.

Results: Of 726 ITP patients, 2 (0.27%) patients’ plasma significantly inhibited platelet aggregation induced by collagen-1. After five rounds of selection, enrichment, and purification, a soluble phage antibody fragment was produced, which can inhibit platelet aggregation induced by collagen-1. The results demonstrate that only a few of the screened anti-platelet GPVI auto-antibodies showed an inhibitory effect on platelet aggregation.

Discussion: A completely humanized anti-GPVI soluble phage antibody can be produced by phage surface display technology. The antibody was able to specifically block collagen-induced platelet aggregation without influencing the aggregation responses to other agonists.

Conclusions: Results of the present study suggest that very few anti-platelet GPVI auto-antibodies inhibit the aggregation function of platelet. The humanized anti-platelet GPVI produced by phage surface display technology is promising to be used to inhibit platelet aggregation in the treatment of cardiovascular disease.     

Analysis of anti-platelet antibody

Results obtained by analysis of anti-platelet antibody using flow cytometry (FCM) were as follows. The use of nest gating is useful in analysis of anti-platelet antibody and frequency of antibody production were 32.7% in patients with hematological disorders using FCM method. This method was much correlated to AHG-LCT method. The rate of coincidence was 92.1%. And effective rate of platelet transfusion of cross match carried out only by FCM method was 81.3%. Concentration of globulin fraction in patient's serum and avidin-biotin assay are useful for increasing the sensitivity of detection of anti-platelet antibody. Elimination of HLA (Class 1) antigen from platelet's surface is effective in both chloroquine and acid treatment. Background of fluorescent intensity was tendency to low by the acid treatment than by chloroquine one. It is possible that high titer serum of allogeneic anti-platelet specific antibody is able to be identified by means of its fluorescent intensity.     

Incidence and clinical significance of anti-PF4/heparin antibodies of the IgG, IgM, and IgA class in 755 consecutive patient samples referred for diagnostic testing for heparin-induced thrombocytopenia

BACKGROUND: Heparin-induced thrombocytopenia (HIT) is usually caused by anti-platelet factor 4 (PF4)/heparin antibodies, leading to intravascular platelet activation. These antibodies can be detected by PF4/polyanion antigen assays or platelet activation assays. While antigen assays are very sensitive and recognize immunoglobulin (Ig)G, IgA, and IgM antibodies, the role of IgM and IgA HIT-antibodies is debated. Platelet activation assays recognize IgG and are more specific for clinical HIT. METHODS: We analyzed sera from 755 consecutive patients referred for diagnostic testing for HIT using a PF4/heparin enzyme-linked immunosorbent assay (ELISA) for IgG, IgA, and IgM and by the heparin-induced platelet activation (HIPA) test. Clinical information was provided by the treating physicians. RESULTS: A total of 108 of 755 (14.3%) patients tested positive, 105 (13.9%) in the PF4/heparin IgG/A/M ELISA [28 (26.7%) only for IgM/A]; 53 (7.0%) sera were positive in the HIPA, of those 50 tested also positive in the ELISA. In 77 patients sufficient clinical information was provided. Available clinical information for 17 of the 28 patients who had only IgM and/or IgA detected showed plausible alternative (non-HIT) explanations in four of seven who had thromboembolic complications and in nine of 10 who had isolated HIT. CONCLUSION: Detection of IgG, IgM and IgA class antibodies by PF4/heparin ELISA yields a positive test result about twice as often as does a platelet activation assay, with only a minority of the additional patients detected likely having HIT. Thus, there is a potential for considerable over-diagnosis of HIT by laboratories that utilize only an ELISA for diagnostic testing.     

New Platelet Antigen, Siba, Involved in Platelet Transfusion Refractoriness in a Japanese Man

Siba, a new platelet-specific alloantigen involved in a case of platelet transfusion refractoriness is reported. The IgG platelet alloantibody was detected in a multiply transfused patient of Japanese extraction (Sib), by the presence of HLA antibodies. After transfusion of HLA-compatible platelets, the patient suffered from refractoriness. Adsorption studies with pooled lymphocytes showed that the serum contained anti-platelet activity. Family studies indicate that Siba is inherited as an autosomal codominant trait and separate from HLA and Baka. As of this report, segregation from Zw(PlA) and Yuk (Pen) antigen systems have not yet been determined. The gene frequency of Siba in the Japanese population is estimated to be 0.136.     

Effects of IgG and its F(ab')2 fragments of some patients with idiopathic thrombocytopenic purpura on platelet aggregation

OBJECTIVES: To make humanized monoclonal antibodies by phage surface display technology, we screened out the specific anti-platelet glycoproteins (GPs) IgG antibody from patients with chronic idiopathic thrombocytopenic purpura (ITP), which can inhibit platelet aggregation. METHODS: We studied plasmas from 68 patients with ITP for the presence of IgG antibodies specific for GPIIb/IIIa and/or GPIb/IX using modified monoclonal antibody immobilization of platelet antigen assays. The IgG antibody and its F(ab')(2) fragments of the positive plasmas which could inhibit platelet aggregation function were prepared and purified. Their immunoreactivity to platelet GPs and effects on platelet function were further analyzed. RESULTS: GPIIb/IIIa- and GPIb/IX-specific antibodies were found in 21 and 19 patients, respectively. Six of them had antibodies against both GP complexes. Among the 34 positive plasmas, four with positive anti-GPIIb/IIIa autoantibody showed significant inhibition of platelet aggregation induced by adenosine diphosphate (ADP), whereas one with GPIb/IX-specific antibody inhibited ristocetin-induced platelet aggregation. The purified IgG and its F(ab')(2) fragments from two patients not only retained the ability to bind to platelet GPs but also impaired the in vitro ADP-induced platelet aggregation. CONCLUSIONS: F(ab')(2) portion of the IgG is a functional fragment, which is responsible for the autoantibody interaction with platelet GPs in ITP, and some of them also affect platelet function, which can be used to develop completely humanized anti-GPIIb/IIIa small molecular phage antibody.