机采新鲜血小板与新鲜冰冻血小板的临床疗效分析

目的分析机采新鲜冰冻血小板的临床应用效果,缓解抢救患者时新鲜血小板供不应求的现象。方法将患者随机分为两组．分别采用机采新鲜血小板与机采新鲜冰冻血小板进行临床输注,观察输注前后患者的临床体征及血小板计数。结果机采新鲜血小板组疗效显著优于新鲜冰冻血小板组（P〈0．05）。结论机采新鲜冰冻血小板可用于抢救因血小板减少导致的出血性疾病患者。     

冰冻血小板与新鲜血小板的疗效比较

目的比较冰冻血小板和新制备的血小板的在临床上的应用效果。方法选268例新制备的血小板与296例冰冻的血小板输注病例,观察两组输注血小板前后的临床表现并进行血小板的计数。结果在564例病案中,输注新制备血小板后的患者外周血血小板上升的程度和总有效率明显高于输注冰冻血小板的患者,两者之间差异有显著性(P<0.05)。结论输注新鲜血小板或冰冻血小板均能达到控制及预防出血的治疗作用,并且提升机体血小板数值,虽然新鲜血小板的疗效优于冰冻血小板,但冰冻血小板可以在抢救危重患者时代替机采新鲜血小板。     

冰冻血小板制备研究

[目的]探讨冰冻单采血小板制备的可行性,为其临床应用提供可靠依据.[方法]通过认真选择献血员,单采血小板,并对40袋新鲜血小板进行计数等质控,用二甲基亚砜（DMSO）作冰冻保护剂,-80℃深低温保存1年内,解冻后观察外观,分别进行计数、计算回收率、测定PH值、粘附率、无菌试验,并且与新鲜血小板进行比较.[结果]-80℃保存冰冻单采血小板1年内血小板计数、pH值、粘附率与冻前新鲜血小板进行比较差异无显著性（P〉0.05）;血小板平均体积、血小板体积分布宽度冰冻前后差异有显著性（P〈0.01）,保存1年内平均回收率为90.49% , 无菌实验无细菌生长.[结论]-80℃深低温保存冰冻血小板质量达到标准要求,可以应用于临床.     

血标本室温放置时间对血小板聚集的影响

目的探讨血标本室温放置时间对血小板聚集的检验结果影响。方法随机采集126例门诊体检健康志愿者静脉血标本,枸橼酸钠抗凝,离心分离富含血小板血浆（PRP）和贫血小板血浆（PPP）,采用血浆比浊法,分别在不同的时间点测血小板聚集率。结果标本室温放置1.5～24h,10μmol／L二磷酸腺苷（ADP）诱导血小板聚集率为（75．0±11．O）%～（28．7±11．5）％（F=244．84,P〈0．01）,0．5mmol／L和1．0mmol／L花生四烯酸（AA）诱导血小板聚集率分另q为（83．2±8．7）％～（6．7±1O．4）％（F=71．09,P〈0．01）,（84．6±8．5）％～（11．2±16．7）％（F=101．90,P〈0．01）,都随时间延长而降低;pH值为（7．78±0．07）～（8．43±0．09）,随时间延长而增大。结论标本室温放置时间对ADP和AA诱导血小板聚集有明显的影响。10μmol／LADP和0．5mmol／LAA诱导血小板聚集,标本检测需在4h内完成,血小板聚集率随时间延长而降低可能与标本老化、pH过高有关。     

Procoagulant platelets: Generation,characteristics, and therapeutic target

Platelets play a pivotal role in hemostasis. Activated platelets are classified into two groups, according to their agonist response: aggregating and procoagulant platelets. Aggregating platelets consist of activated integrin αIIbβ3 and stretch out pseudopods to further attract platelets to the site of injury by connecting with fibrinogen. They mainly gather in the core of the thrombus and perform a secretory function, such as releasing adenosine diphosphate (ADP). Procoagulant platelets promote the formation of thrombin and fibrin by interacting with coagulation factors and can thus be considered as the connector between primary and secondary hemostasis. In addition to their functions in blood coagulation, procoagulant platelets play a proinflammatory role by releasing platelet microparticles and inorganic polyphosphate. Considering these important functions of procoagulant platelets, this subpopulation warrants detailed study to analyze their potential in preventing human diseases. This review summarizes the generation and important characteristics of procoagulant platelets, as well as their potential for preventing the adverse effects associated with current antiplatelet therapies.     

Cryopreserved buffy-coat-derived platelets reconstituted in platelet additive solution: A safe and available product with sufficient haemostatic effectiveness

BackgroundPlatelets (PLTs) stored at 20–24 °C have a short shelf life of only 5 days, which can result in their restricted availability. PLT cryopreservation extends the shelf life to 2 years.MethodsWe implemented a method of PLT freezing at ?80 °C in 5–6% dimethyl sulfoxide. Buffy-coat-derived leucodepleted fresh PLTs blood group O (FP) were used for cryopreservation. Cryopreserved pooled leucodepleted PLTs (CPP) were thawed at 37 °C, reconstituted in PLT additive solution SSP + and compared to FP regarding PLT content, PLT concentration, pH, volume, PLT loss, anti-A/B antibody titre, total protein, plasma content, and PLT swirling. Clot properties were evaluated via rotational thromboelastometry. PLT microparticle number and surface receptor phenotype were assessed via flow cytometry.ResultsCPP met the required quality parameters. The mean freeze-thaw PLT loss was 22.24 %. Anti-A/B antibody titre and plasma content were significantly lower in CPP. CPP were characterised by faster clot initiation and form stable PLT clots. The number of PLT microparticles increased 25 times in CPP and there were more particles positive for the activation marker CD62 P compared to FP.ConclusionThawing and reconstitution are easy and fast processes if platelet additive solution is used. Low anti-A/B antibody titre and plasma content make possible the use of CPP of blood group O reconstituted in SSP + as universal ABO products, including clinical situations where washed PLTs are required. Clot properties evaluated via rotational thromboelastometry demonstrated that CPP retain a significant part of their activity compare to FP and are haemostatically effective.     

Concentration changes to counteract the effects of bacteriological sampling on PLT yields

Introduction: Bacterial culturing of apheresis platelet (PLT) units appeared to increase the incidence of low yield products of <3.0 × 10¹¹ PLT (LYP) and decrease the incidence of multiple PLT products. To determine the effects of sampling and subsequent modifications in collections on PLT yield and adverse reactions, a retrospective analysis was performed. Methods: Four time periods were examined: baseline, after sampling implementation, after concentration change (Conc. Δ) implementation, and after concentration and yield target change (Target + Conc. Δ) implementation. Collections were performed on the Gambro Trima Accel. PLT concentration settings were changed from 1,550 to 1,200 (single and double PLT products) or 1,610 to 1,500 (triple PLT products). A 3.2 × 10¹¹ target was eliminated and a 9.4 × 10¹¹ target added. Results: Donors in all groups were comparable. Average incidence of LYP per week was significantly higher for Sampling (8.1%) than Baseline (2.0%) and declined significantly in the Conc. Δ (3.4%) and Target + Conc. Δ (2.0%) groups. Average PLT products/donor per week for Sampling (1.7) was significantly lower than Baseline (1.8), equivalent to Conc. Δ (1.7), and significantly lower than Target + Conc. Δ (1.9). Average weekly incidence of triple PLT products was significantly higher for Target + Conc. Δ (17%) compared with Baseline (12.4%), Sampling (10.7%), and Conc. Δ (10.8%). Donor reaction incidence was not significantly different among the groups. There was no change in recipient reactions. Conclusions: The use of a yield target change and PLT concentration reduction compensated for changes associated with bacterial culturing without increasing donor or recipient reactions. J. Clin. Apheresis, 2008. © 2008 Wiley‐Liss, Inc.     

Comparison of efficacy of low and high dose prophylactic platelet transfusion therapy in thrombocytopenic haemato-oncology patients

IntroductionTo determine an optimal platelet dose in thrombocytopenic patients is important for their judicious use. Transfusing platelets in different doses and comparing their post transfusion response can achieve this.AimTo compare the efficacy of low and high dose single donor apheresis platelets (SDAP) with standard dose transfusions in terms of Corrected Count Increment (CCI), Percent Platelet Recovery (PPR) and transfusion free interval.MethodIt was a prospective case control study done from January 2016 to April 2017. Twenty-eight hemato-oncology patients with CCI ≥5000 at 20–24 hours after standard dose (3 × 10¹¹/unit), received low dose (1.5 × 10¹¹ platelets/unit) and high dose (>4 × 10¹¹ platelets/unit) SDAP. CCI and PPR were calculated after 20 to 24 hours of transfusion. Transfusion free interval and bleeding episodes were also noted. Grading was done according to WHO bleeding scale.ResultThere was no statistical difference in CCI and PPR when standard dose was compared with low dose (CCI: p = 0.92, PPR: p = 0.89). When standard and high dose was compared, standard dose gave better results than the high dose in terms of CCI (p = 0.006) and PPR (p = 0.008) although the post transfusion increments were comparable (p = 0.938). High dose gave better (p = 0.005) platelet count increments than low dose but CCI (p = 0.04) and PPR (p = 0.05) was significantly less than the low dose. The difference in transfusion free intervals after three doses was not significant. Donor exposure to the patients was significantly (p = 0.000) reduced to 17.5%.ConclusionPossibility of low dose as an alternative to standard dose can be considered in view of comparable platelet response indicators and significantly reduced donor exposure.     

Evaluation of platelets collected by a new portable apheresis device

We studied the efficiency of platelet collection by the Mobile Collection System (MCS) using two types of experimental protocols and evaluated the effect of storage at 22°C on the platelet concentrates (PC). MCS is a new blood cell separator that combines discontinuous flow features with a new computerized operating system and can be used to harvest either full units of apheresis PC (SDP _protocol) or half units of PC together with one to two units of plasma (PLP _protocol). On the average, 1.98 × 10¹¹ ± 0.46 × 10¹¹ (mean ± SD) platelets were obtained by the PLP protocol and 3.01 × 10¹¹ ± 0.70 × 10¹¹ and 4.2 × 10¹¹ ± 1.12 × 10¹¹ by the early and later versions of the SDP protocols, respectively. The mean number of WBC per PC ranged from 3.3 to 4.7 × 10⁸. During the storage period pH stayed above 7.0. On the average, the production of one molecule of lactate corresponded to the consumption of 0.538 molecules of glucose, indicating that less than 8% of glucose was consumed by the oxidative pathway. There were only small increases in LDH and B thromboglobulin concentrations. Furthermore, the ability of platelets to recover from osmotic shock and to aggregate following exposure to dual agonists declined only slightly during storage, indicating that both viability and function of platelets collected by the MCS were preserved during storage. © 1993 Wiley-Liss, Inc.     

Platelets and autoimmunity

Vascular injury is the initial manifestation of inflammation resulting in the recruitment and activation of various cell types. The integrity of the vascular wall is monitored by platelets that become activated in the presence of exposed subendothelium. Besides their well‐established role in haemostasis, ample data are now emerging on the many immunoregulatory functions of platelets. Platelets store and release a large plethora of cytokines, chemokines and growth factors. They also represent the largest circulating pool of many inflammatory mediators like P‐selectin, CD40L and non‐neuronal serotonin. Furthermore, complement activation occurs on the platelet surface and deposition of complement results in platelet activation. Overall, platelets have multiple functions in both innate and adaptive immunity. Further insight into the multifaceted role of platelets could therefore provide important clues into how we could implement current platelet therapy to reduce both platelet‐induced thrombosis and inflammation. In this review, we discuss the current perceptions of platelet involvement in various autoimmune diseases like rheumatoid arthritis, systemic lupus erythematosus, systemic sclerosis and multiple sclerosis.     

Preferential localization of recombinant factor VIIa to platelets activated with a combination of thrombin and a glycoprotein VI receptor agonist

BACKGROUND: Activation of platelets with a combination of collagen and thrombin generates a subpopulation of highly procoagulant 'coated' platelets characterized by high surface expression of fibrinogen and other procoagulant proteins. OBJECTIVES: To analyze the interaction of recombinant factor VIIa (rFVIIa) with coated platelets. METHODS AND RESULTS: rFVIIa localized to the coated platelets in flow cytometry experiments, while minimal rFVIIa was found on platelets activated with adenosine diphosphate, thrombin or via glycoprotein VI individually, and essentially no rFVIIa was found on non-stimulated platelets. Removal of the gamma-carboxyglutamic acid (Gla) domain of rFVIIa, and addition of EDTA, annexin V or excess prothrombin inhibited rFVIIa localization to the coated platelets, indicating that the interaction was mediated by the calcium-dependent conformation of the Gla domain and platelet exposure of negatively charged phospholipids. A reduced level of platelet fibrinogen exposure was observed at hemophilia A-like conditions in a model system of cell-based coagulation, indicating that coated platelet formation in hemophilia may be diminished. Addition of rFVIIa dose-dependently enhanced thrombin generation and partly restored platelet fibrinogen exposure. CONCLUSIONS: The data suggest that rFVIIa localized preferentially on platelets activated with dual agonists, thereby ensuring enhanced thrombin generation localized at the site of injury where both collagen and tissue factor are exposed, the latter ensuring the formation of thrombin necessary for coated platelet formation.     

New Design of Volumetric Respirometer

Serum creatine phosphokinase (CPK), a-hydroxybutyric dehydrogenase (HBD), glutamic oxalacetic transaminase (GOT) and lactic dehydrogenase (LDH) activities were measured in late pregnancy some days before and during delivery, and 5 days after delivery in a series of 30 mothers and their 15 newborn infants. Furthermore, daily determinations of these enzymes were made in 10 mothers up to the fourteenth postpartum day.

Elevated CPK activity in the serum was observed in late pregnancy, particularly during and some days after delivery. LDH and HBD showed some elevation at delivery. GOT had no tendency 30 rise in these circumstances. In newborn infants the serum LDII and HBD activities were about twice as high as those seen in their mothers, but the serum GOT activity was not greater in the umbilical cord than in the maternal serum. It seems possible that the increase of CPK activity in the serum may partly be accounted for by release from the uterus musculature, which was found to have increased CPK activity in pregnancy.     

单、双份机采血小板对捐献者血常规的影响

目的探讨单、双份机采血小板对捐献者血常规的影响,以评价双份机采血小板的效率和安全性。方法 2015年1月至2016年1月,便利抽样法选择在深圳市血液中心进行机采血小板捐献者100名为研究对象。按随机数字表法将其分为单份机采组和双份机采组,每组50名。在机采前和机采后(献血后5 min),采用血细胞计数仪检测其血常规。在机采时,注意观察捐献者的生命体征的变化。结果两组捐献者机采血小板成品合格率为100%,捐献者生命体征均基本平稳。采集前、后,两组捐献者白细胞计数(white blood cell count,WBC)差异无统计学意义(P0.05);而采集后,两组捐献者血红蛋白(hemoglobin,HGB)、红细胞计数(red blood cell count,RBC)、血细胞比容(hematocrit,HCT)、血小板(platelets,PLT)均较采集前有所降低,差异均有统计学意义(均P0.05)。机采血小板前,两组捐献者WBC、HGB、RBC、HCT、PLT的差异均无统计学意义(均P0.05);机采血小板后,两组捐献者WBC、HGB、RBC、HCT的差异均无统计学意义(均P0.05),而PLT的差异有统计学意义(P0.05)。献血后,两组捐献者外周血中PLT的计数均高于国家标准。结论双份机采血小板方法既高效又安全。     

Lymphocyte subpopulations of plateletapheresis products collected with the Fenwal CS-3000 Cell Separator

To determine whether any lymphocyte subset is preferentially harvested and transfused as a consequence of plateletapheresis with the Fenwal CS-3000 Blood Cell Separator, the proportions of lymphocyte subpopulations in platelet concentrates were compared to their proportions in the donors' peripheral venous blood immediately prior to platelet collection. There was no difference in the proportion of B cells (surface immunoglobulin positive), T cells (OKT3 positive), helper/inducer T cells (OKT4 positive), suppressor/cytotoxic T cells (OKT8 positive), and natural killer cells (Leu 7 positive) in the donors' peripheral venous blood and the plateletapheresis product. Thus, although previous studies have demonstrated the ability to separate lymphocyte subpopulations by density centrifugation and velocity sedimentation, plateletapheresis with the CS-3000 harvests the lymphocyte subpopulations studied in the same proportions in which they circulate in donors' peripheral venous blood.     

替罗非班致出血27例临床分析

目的:总结替罗非班致出血的临床表现及致出血因素。方法:回顾性分析2011年1月-2013年8月接受替罗非班治疗并发出血的冠心病患者27例的临床资料。结果:本组≥65岁患者占81.5%(22/27);18例有相关的基础疾病,3例发生在PCI术后,6例无明显诱因;肉眼血尿8例,牙龈出血5例,咯血4例,鼻衄3和皮下瘀斑各3例,心包填塞、右前臂出血血肿、右股动脉血肿及消化道出血各1例;21例患者停药后出血可自愈,6例经对症处理止血。结论:替罗非班治疗冠心病致出血并发症的临床表现多样;致出血相关因素有介入操作技术及器械选择、合并相关基础疾病、老龄:用药时需密切观察出血情况并及时处理。     

Platelet characteristics associated with coronary artery disease

Summary.  Background/objective : To test the hypothesis that circulating platelets display evidence of interactions with atherogenesis, platelet capacity to express P-selectin and propensity for spontaneous microaggregation in vitro were measured in samples from normal donors (N), patients with asymptomatic advanced coronary calcification (CC) or acute coronary syndromes (AC). To measure the effect of angioplasty on platelet function, samples obtained before, 30 min after and 24 h after angioplasty were compared. Patients/methods : Platelet P-selectin was measured after maximal stimulation with thrombin. Microaggregation was measured as a platelet count deficit in citrate-anticoagulated platelet-rich plasma (PRP) relative to EDTA-anticoagulated blood. Results : P-selectin expression was significantly lower for platelets from patients with either AC or CC compared to normals. In addition, platelets from AC and CC patients have a significantly greater propensity to form microaggregates in citrate anticoagulant. After angioplasty, the PRP-platelet count decreased transiently. Conclusion : Both acute unstable and chronic stable coronary disease are associated with an increased share of platelets unable to express P-selectin and an increased share of platelets that microaggregate in citrate anticoagulant. The genesis of these platelet characteristics is not fully explained by focal acute arterial injury and may reflect exposure to systemic atherosclerosis or the atherogenic process.     

Platelet size and volume distribution measured by automated platelet analyzer

Thirty migraine without aura patients between attacks, 10 other during a migraine without aura attack and 30 normal subjects without headache were studied for platelet size and volume distribution using a new quantitative automated hematology analyzer (Coulter STKS). Platelet histograms, platelet counts and mean platelet volume were not significantly different in the three populations.     

Thrombin-triggered platelet apoptosis

BACKGROUND: Thrombin is primarily known as a coagulation factor and as an inducer of platelet activation and aggregation. It has been reported that thrombin modulates apoptosis of nucleated cells. OBJECTIVES: The current study investigated whether thrombin can affect apoptosis in anucleated human platelets. METHODS: Using flow cytometry, we studied platelet apoptosis at the single-cell level, analyzing markers of mitochondrial and cytoplasmic apoptosis. Western blotting was also employed, in addition to flow cytometry, for determining the expression of Bcl-2 family proteins. RESULTS: We found that human alpha-thrombin induced four key manifestations of apoptosis in human platelets: (i) mitochondrial inner transmembrane potential (DeltaPsi m) depolarization; (ii) strong expression of pro-apoptotic Bax and Bak proteins but only weak expression of anti-apoptotic Bcl-2 protein; (iii) caspase-3 activation; and (iv) phosphatidylserine (PS) exposure. CONCLUSIONS: This study demonstrates that, aside from its 'classical' function as an inducer of platelet activation, thrombin can trigger platelet apoptosis, where it acts as a death ligand. These data indicate that thrombin triggers platelet apoptosis by impacting on several intracellular apoptotic targets, including shifting the balance between Bcl-2 regulatory proteins in a pro-apoptotic direction, depolarizing the inner mitochondrial membrane, activating the executioner caspase-3, and stimulating aberrant exposure of PS on the platelet surface.