Improvement of platelet function following plateletpheresis in patients with myeloproliferative diseases

Four patients with myeloproliferative diseases and acute hemorrhagic or thrombotic complications of thrombocytosis were treated with plateletpheresis by discontinuous-flow centrifugation. Reduction of platelet counts was achieved rapidly, without complications and was associated with clinical improvement. In all four cases, abnormal platelet aggregation testing was present before pheresis, but improved immediately after pheresis. Platelet-sizing data obtained in one case suggested that during the pheresis procedure, a population of larger volume platelets was selectively removed. The efficacy of plateletpheresis in these clinical situations may be related to the selective removal of a large abnormal platelet population.     

80例献血者机采血小板前后血液电解质及pH值的变化

目的探讨机采血小板献血者采集前后血液电解质及pH值的变化及其意义。方法采集前、采集后即刻取机采血小板献血者血清作电解质及pH值检测,对所得数据进行统计学分析。结果采集后献血者血液钾（K^＋）、氯（Cl^-）、钙（Ca^2＋）离子浓度降低（P值均〈0.01）;钠（Na^＋）离子和pH值未发生明显变化（P值均〉0.05）。结论机采血小板后献血者钾（K^＋）、氯（Cl^-）、钙（Ca^2＋）离子浓度降低,但仍然在生理范围内,捐献机采血小板是安全的,不会造成献血者血液电解质紊乱和pH值明显改变。     

The effects of combined platelet and leukapheresis on the blood coagulation system

Analysis of blood coagulation was done on samples of blood collected from ten donors undergoing combined platelet and leukapheresis using the Haemonetics Model 30 Blood Processor. Blood samples were obtained from the donors prior to, during, and following pheresis. Blood was also obtained from the blood-return line after the first collection of leukocytes and platelets, but before it was returned to the donor. Although the citrate anticoagulant was returned to the donor and there were some decreases in the concentrations of fibrinogen, platelets, and factors V and VIII, there were no changes of sufficient degree to suggest that development of a potential bleeding disorder. In addition there was no evidence to suggest that any activation of blood coagulation occurred during the pheresis or that thrombogenic substances were returned to the donors. Combined platelet and leukapheresis using the Haemonetics Model 30 Blood Processor, therefore, do not appear to subject the donor to risks for either bleeding or thrombotic complications.     

Donor platelet response and product quality assurance in plateletpheresis

Retrospective analysis of 352 donors who underwent plateletpheresis at least four times, each using the Haemonetics Model 30 Blood Processor, indicated that a postpheresis platelet count of less than 100,000/microliter occurred in only 2.7 per cent of phereses. Restricting pheresis to those with a prepheresis platelet count of greater than 150,000/microliter would have lowered this to 1.3 per cent and eliminated only 3.7 per cent of donations. The donors' platelet counts returned to baseline approximately four days and rebounded above baseline eight to eleven days after pheresis. To minimize the chance of a donor having a postpheresis platelet count less than 100,000/microliter, the prepheresis platelet count should be greater than 150,000/microliter. A platelet count greater than 150,000/microliter immediately following the previous pheresis can be used instead of the prepheresis platelet count. The yield was related to the prepheresis platelet count, number of cycles, sex, type of procedure (platelet or platelet-leukapheresis), and the yield recorded during an individual's previous procedures. Seventy-five per cent of plateletpheresis products contained more than 3.3 × 10(11) platelets. This might be a satisfactory standard for quality assurance.     

Function and morphology of platelets produced for transfusion by intermittent-flow centrifugation plateletpheresis or combined platelet- leukapheresis

The effects on platelet function of intermittent-flow centrifugation pheresis were measured employing platelets collected from ten donors by combined platelet-leukapheresis with hydroxyethyl starch (LP) and from ten by plateletpheresis (PP) by similar techniques except without starch. Greater numbers of platelets were produced by LP than by PP. Aggregation of platelets collected by both LP and PP was normal (did not differ from prepheresis baseline) to collagen and to 10(-5)M adenosine diphosphate (ADP). Slight impairment to aggregation with 2 X 10(-6)M ADP and 5.5 X 10(-5)M epinephrine occurred with both techniques. These abnormalities, however, were significantly less severe in platelets collected by LP. Platelet morphology by electron microscopy was nearly normal, although glycogen granules were absent in LP platelets. Thus, hydroxyethyl starch, at doses currently used during a single LP, does not enhance abnormalities of platelet aggregation over those expected to result from PP alone. Actually, LP platelets function better in vitro than those collected by PP. Large numbers of platelets can be harvested by LP, and their use as a component that is comparable to PP platelets may mean improved efficiency and reduced costs for pheresis centers.     

Mechanism of Transfusion-induced HLA alloimmunization

<正>Platelet transfusion therapy has allowed successful prevention and treatment of hemorrhagic complications associated with thrombocytopenia since its first use in the 1960's.Consequently, the use of platelets has increased at an exponential rate.Since platelet     

Long-term plateletpheresis in the management of primary thrombocytosis

We attempted to control the platelet count of a patient with primary thrombocytosis utilizing long-term plateletpheresis therapy. The patient previously could not be controlled with chemotherapy, because of rapid development of leukopenia. Although intensive pheresis at the rate of four to five procedures per week produced rapid lowering of the patient's platelet count, continued therapy at the rate of two to three procedures a week failed to maintain these counts, and platelets gradually rose to pretreatment levels. We conclude that while plateletpheresis can produce acute lowering of elevated platelet counts, the rate of platelet production in primary thrombocytosis may be too rapid to allow for long-term control by pheresis alone, utilizing an acceptable treatment schedule of one of three procedures per week.     

Thrombocyte replacement in hematologic diseases

This report presents a strategy for platelet support, which was used in patients suffering from acute leukaemia undergoing remission induction, and in patients treated by bone marrow transplantation (BMT) or by antithymocyte globulin (ATG). Platelet concentrates were produced from single donors by means of platelet pheresis with cell separators, with a yield of 3.0 to 4.0 X 10(11) platelets per platelet pheresis. Platelet support was investigated in 84 patients with acute leukaemia, median age 43 years (range 14 to 86), in 36 patients with BMT, median age 22 years (range 3 to 14) and in 6 patients treated with ATG, median age 40 years (range 11 to 44). Platelet transfusions were performed when the platelet count was about 20 X 10(9)/l, whether or not haemorrhage was present. When diagnostic puncture was performed or surgical intervention was necessary, platelets were given at a platelet count of below 80 X 10(9)/l. During remission induction the patients with acute leukaemia required, on average, 8 platelet concentrates, whereas in patients undergoing BMT the transfusion of 4 to 15 platelet concentrates was necessary, depending on the underlying disease. The requirement for patients treated with ATG was about 20 platelet concentrates. This strategy contributed to the low mortality of 3% from haemorrhage, despite the aggressive treatment.     

Hypercoagulable state induced by thrombocytapheresis

The influence of the continuous-flow automated blood cell separator, Fenwal CS-3000, on blood coagulation and the fibrinolytic system in blood donors was studied. Blood samples were taken from the collection line of donors undergoing extracorporeal circulation, before and after platelet pheresis. Of the molecular markers, prothrombin fragment-Fl + 2 (PFI + 2) markedly increased from 0.8 ± 0.3 to 2.9 ± 2.0 nM/ml (P < .004), thrombin antithrombin III complex (TAT) also markedly increased from 2.6 ± 1.3 to 56.0 ± 24.0 μg/L (P < .001), fibrinopeptide A (FPA) increased slightly from 0.8 ± 0.9 to 3.8 ± 4.2 μg/L (P < .05), and α2-plasmin inhibitor (α2-PI) decreased slightly from 95 ± 8 to 91 ± 9% (P < .05). In one donor with the highest level of PFI + 2, TAT, FPA, and plasmin inhibitor complex after platelet pheresis, protein C, protein S, C4b-binding protein, ATIII, plasminogen, α2-PI, and coagulation factors were decreased. In blood donors undergoing platelet pheresis using the continuous-flow automated blood cell separator, Fenwal CS-3000, a hypercoagulable state was observed. Changing the materials of the plastic disposables to a more thromboresistant material may prevent the hypercoagulable state in donors induced by platelet pheresis using the blood cell separator. © 1993 Wiley-Liss, Inc.     

中间型人工肝对重型肝炎肝功能支持的效果评价

目的　评价中间型人工肝支持方法血浆置换对重型肝炎肝功能的支持效果和安全性。方法　对 17例重型肝炎患者进行血浆置换治疗 ,观察治疗前后患者临床症状、体征变化 ,比较治疗前后肝、肾功能 ,血常规 ,凝血酶原时间 (PT)和凝血酶原活动度 (PTa)变化。结果　血浆置换治疗后 ,患者的临床症状均有不同程度改善 ,总有效率为 5 8.8% ,最终存活率仅为 11.8%。检测指标中转氨酶、总胆红素、凝血酶原时间、凝血酶原活动度和总蛋白治疗前后差异均有显著性 (P<0 .0 5或 P<0 .0 1) ;血尿素氮、血肌酐和血常规各指标治疗前后差异均无显著性 (P均 >0 .0 5 ) ;而且不良反应较轻。结论　中间型人工肝对重型肝炎患者肝功能有肯定的支持效果。     

血浆置换术用于难治性甲型肝炎高胆红素血症的效果

我们应用国产HF血液成分分离机,对6例平均病程为10周,药物治疗无效的甲型肝炎高胆红素血症患者,共作26次血浆置换术.每次平均单采患者血浆760ml,并补充等量的同型新鲜冰冻血浆.每次血浆置换后,血清胆红素平均下降90.6μmol/L(相当于5.3mg/dl),全部病例均获满意的效果.     

Modified method of exchange transfusion in sickle cell disease

The treatment of various complications of sickle cell disease has included red cell exchange in the past, and the development of automated pheresis equipment has greatly simplified such exchanges. Traditionally, the patient's red cells have been exchanged while their plasma was returned to them. Recently, plasma factors have been thought to play a role in the pathogenesis of vasoocclusive events. Therefore, we performed whole blood exchange, which consisted of replacement of the patient's plasma with albumin and saline in addition to the usual replacement of erythrocytes. A total of 32 whole blood exchanges were performed on 12 patients with a variety of complications of their disease. The procedure was done using standard pheresis equipment and was relatively simple to perform. There were no serious complications and the clinical outcome was good with 10 out of 12 patients experiencing improvement.     

单采和手工血小板治疗效果的Meta分析

目的应用Meta分析方法系统评价单采和手工血小板在临床输血治疗中提升血小板的疗效。方法计算机检索CBM、CNKI、VIP、万方等数据库。收集应用单采和手工血小板在临床输血治疗中提升血小板的随机和半随机对照试验,采用Review manager5.0软件对资料进行Meta分析。结果共纳入4个研究,1 008例患者。Meta分析结果显示,与输注手工血小板组相比,单采血小板组血小板计数增加校正指数(CCI)明显升高(WMD=5.46,95%CI:2.75～8.17,P<0.01);实际血小板回收率(PPR)亦提高(WMD=14.17,95%CI:7.75～20.59,P=0.05);输血反应发生率也较低(RR=0.28,95%CI:0.16～0.48,P<0.01)。结论输注单采血小板制剂能更有效地提高患者的血小板值,临床止血效果优于输注手工血小板制剂,并减少其血小板输注无效及输血反应的发生。     

Frequent multiunit plateletpheresis from single donors: effects on donors' blood and the platelet yield

Two thousand plateletpheresis procedures performed on 335 donors by either semicontinuous flow centrifu-gation (Haemonetics Model 30) or a multiple bag technique were analyzed for effects on donors and the yield of platelets. The platelet yield was independent of collection method, number of prior donations and donor's hematocrit. It varied directly with the donors' platelet count and was significantly higher for women donating by semi-continuous flow centrifugation. Even at the lowest platelet harvest, the number of platelets obtained was sufficient to meet federal standards for platelet collection procedures. Donor platelet counts decreased following the first multiunit plateletpheresis procedure. After the equivalent of continued alternate day platelet collections the count reached a mean low of 70 per cent as compared to the precollection count, occurring after six to eight donations. The yield was comparably reduced to a mean of 64 per cent. By the tenth donation platelet counts had returned to baseline values, apparently as a result of increased production by the marrow. Similarly, platelet yields returned to higher (i.e. normal) levels. Further donations did not cause platelet counts or yields to vary from normal values. Repeated daily plateletpheresis resulted in more variability in donor platelet counts. Since none of the donors was subjected to this procedure for more than nine consecutive days, marrow response could not be assessed. Comparing number of donations, donor platelet counts and subsequent yields, there was no difference between daily pheresis and an alternate day schedule. Donor hematocrits were not changed by these frequent collections and other side effects were not observed. This study indicates that repeated multiunit plateletpheresis can continuously provide adequate platelet yields without adversely affecting donors.     

Cryopreservation of human platelets isolated by discontinuous-flow centrifugation using the Haemonetics Model 30 Blood Processor

Platelets were isolated from normal volunteers by discontinuous-flow centrifugation using the Haemonetics Model 30 Blood Processor. The numerical equivalent of about five single units of platelets collected at each pheresis were frozen together in a −80 C mechanical freezer with a 6% final concentration of dimethylsulfoxide (DMSO) as the cryoprotectant. Platelet freeze-thaw-wash recovery in vitro was about 80 per cent and the platelet recovery value depended upon the method used to enumerate the platelets. The 51Cr survival values in vivo were about 50 per cent less than those in fresh platelets. These values were not significantly different from those seen when platelets were isolated from single units of blood by differential serial centrifugation. Transfusion of two and one-half units of freeze- preserved platelets provided an increase in the recipient's circulating platelet count comparable with that from one unit of fresh platelets. The hemostatic effectiveness of freeze-preserved platelets isolated by discontinuous-flow centrifugation has not yet been studied.     

Fatal Salmonella septicemia after platelet transfusion

A thrombocytopenic, leukopenic patient with multiple myeloma who was given 7 units of platelets died 6 days later from complications of Salmonella heidelberg septicemia. A platelet donor who was asymptomatic at the time of donation had group B Salmonella on stool culture. His clinical history and the results of serologic studies and stool culture were consistent with a mild Salmonella gastroenteritis 5 days before donation. Antibiotic sensitivity patterns and plasmid profiles indicated that the organism (S. heidelberg) isolated from the donor's stool was identical to that isolated from the patient's blood and from the platelet bags. It is believed that low-grade, asymptomatic bacteremia in the donor was the source of infection in the recipient. Food and Drug Administration records contain reports of six septic deaths due to platelet transfusions since 1979, compared with none in the preceding 4 years. Increased use of platelet products and the standard practice of storage at room temperature may contribute to the risk of sepsis after platelet transfusion, particularly in immunocompromised patients.     

Combined platelet-leukapheresis: a technique for preparing separate platelet and granulocyte-platelet units from single donors

One donor can provide separate platelet and granulocyte-platelet units that have the potential to fulfill the needs of two recipients. Combined platelet and leukapheresis were performed in the presence of hyddroxyethyl starch and citrate employing the Haemonetics Model 30 Blood Separator. Platelets and granulocytes were separated subsequently by centrifugation and two individual units were prepared for transfusion. The platelet units contained a mean of 4.4 × 10(11) platelets/unit and were nearly devoid of leukocytes. The combined granulocyte-platelet units contained a mean of 7.38 × 10(9) neutrophils/unit and 3.06 × 10(11) platelets/unit. Thus two separate units containing sufficient numbers of cells for transfusion can be obtained from pheresis of one donor.     

Preparation of random donor leukocyte-poor platelets by cytapheresis

Platelet refractoriness in treatment of multitransfused patients with haematologic malignancies can be delayed or prevented by transfusing leukocyte-poor platelet concentrates. Absence of consensus about the number of residual leukocytes that leads to a delay or prevention of HLA-antibody formation, may be based on a lack of sampling for determination of leukocyte contamination levels in platelet concentrates. From data presented in this study we conclude that if every preparation of platelets is also tested for platelet count, it reduces costs when the pheresis platelets can be split. Transfusion of platelets in patients can also be better evaluated.     

Leukapheresis of patients with chronic granulocytic leukemia (CGL), using the Haemonetics blood processor

By the use of citrated hydroxyethyl starch (HES) as anticoagulant, the Haemonetics blood processor can be used to obtain large numbers of granulocytes from patients with CGL. This report is of 67 leukaphereses on 11 different patients. A median of 1.14 × 10(11) granulocytes was obtained per 6-cycle pheresis (3.4 × 10(10) per liter of blood processed), or eight to ten times the number obtained from comparable leukaphereses of normal donors. High yields of platelets were also obtained, although not in proportion to granulocytes, since some of the patients used as donors have normal or even low platelet counts. The patients tolerated the procedure well, and no adverse reactions to HES were observed. The patients experienced a mean 35 per cent drop in the postleukapheresis WBC count, but in no case was this drop sustained for more than a few days, and no lasting effect on the disease process was observed.     

Cytapheresis in a patient with Sezary syndrome

A patient with Sezary syndrome underwent cytapheresis on the IBM 2997 cell separator. Four procedures were performed over a 12-day period. A total of 8.3 × 10(10) Sezary cells were removed. The patient's skin lesions and lymphadenopathy regressed. Transient thrombocytopenia occurred, requiring platelet transfusion. Although a significant number of platelets were removed by pheresis, this was not sufficient to explain the thrombocytopenia. The patient subsequently died of causes unrelated to the cytapheresis.