Acute hemolytic transfusion reaction in a pediatric patient following transfusion of apheresis platelets

The practice of transfusing ABO-incompatible platelets, driven primarily by concerns about inventory management, has been considered generally safe because the accompanying plasma is usually diluted in the recipient's total blood volume. However, if the platelet product contains a large volume of plasma or a high concentration of incompatible isoagglutinin, there may be hemolysis of the recipient's red cells. Patients with a small blood volume, such as babies and children, are considered to be at particular risk for such a complication. We describe the case of a baby who suffered massive hemolysis of her group A red cells after transfusion of group O Apheresis Platelets containing a high-titered anti-A isoagglutinin. We also offer a review of the literature on this subject and recommendations to avoid acute hemolytic reactions as a result of platelet transfusion.     

两种血小板制剂应用于儿科血液病的临床观察

目的观察并比较机器单采法及手工法分离制备血小板制剂用于儿科血液病输注的效果。方法输注机器单采血小板患儿463例次为机采制剂组,输注手工分离血小板制剂患儿155例次为手工制剂组,分别在输注后24、48及72h作外周血血小板计数,观察临床止血效果、有无输血反应发生,计算血小板计数增加校正指数(CCI)、血小板回升率(PPR)、输注无效率、输血反应发生率等指标。结果输注后24、48、72h,机采制剂组:CCI分别为18.9、15.4、14.1,PPR分别为33.4%、27.8%、25.0%;手工制剂组:CCI分别为11.3、9.4、2.9,PPR分别为20.3%、10.3%、3.8%;机采法制剂组均明显高于手工制剂组(P<0.01)。机采制剂组输注无效率10.58%、输血反应发生率3.02%,手工制剂组相应为32.90%及11.61%,机采组虽都明显低于手工组,但两组均达到较好的临床止血目的,组间无差异。结论输注机器单采血小板制剂能更有效地提高血液病患儿的血小板值,减少其血小板输注无效及输血反应的发生。     

Comparison of platelet transfusion as fresh whole blood versus apheresis platelets for massively transfused combat trauma patients (CME)

BACKGROUND: At major combat hospitals, the military is able to provide blood products to include apheresis platelets (aPLT), but also has extensive experience using fresh whole blood (FWB). In massively transfused trauma patients, we compared outcomes of patients receiving FWB to those receiving aPLT. STUDY DESIGN AND METHODS: This study was a retrospective review of casualties at the military hospital in Baghdad, Iraq, between January 2004 and December 2006. Patients requiring massive transfusion (≥10 units in 24 hr) were divided into two groups: those receiving FWB (n = 85) or aPLT (n = 284) during their resuscitation. Admission characteristics, resuscitation, and survival were compared between groups. Multivariate regression analyses were performed comparing survival of patients at 24 hours and at 30 days. Secondary outcomes including adverse events and causes of death were analyzed. RESULTS: Unadjusted survival between groups receiving aPLT and FWB was similar at 24 hours (84% vs. 81%, respectively; p = 0.52) and at 30 days (60% versus 57%, respectively; p = 0.72). Multivariate regression failed to identify differences in survival between patients receiving PLT transfusions either as FWB or as aPLT at 24 hours or at 30 days. CONCLUSIONS: Survival for massively transfused trauma patients receiving FWB appears to be similar to patients resuscitated with aPLT. Prospective trials will be necessary before consideration of FWB in the routine management of civilian trauma. However, in austere environments where standard blood products are unavailable, FWB is a feasible alternative.     

Markers of platelet activation and apoptosis in platelet concentrates collected by apheresis.

BACKGROUND: A product with well-preserved haemostatic function of platelets is the ultimate goal of platelet concentrate production. However, platelet activation and apoptosis are induced by both collection and storage of platelet concentrates. AIM OF STUDY: Platelet concentrates obtained either by two blood separators with different technology of apheresis (Haemonetics MCS+, Haemonetics Corp. Braintree, USA and Trima Accel, Gambro BCT Inc., Lakewood, USA, respectively) or derived from buffy-coat were compared using evaluation of pH, LDH, lactate, glucose, annexin V, and sP-selectin levels immediately after collecting and at the end of expiration to estimate the differences in the activation and apoptosis of platelets in these products. RESULTS: The lowest degree of platelet activation was found in products obtained by Haemonetics MCS+ apparatus at the time of collection. Platelet concentrates obtained by apheresis revealed higher rise of LDH, annexin V and sP-selectin compared to buffy-coat derived platelets. Products from Haemonetics MCS+ showed higher rise of annexin V in comparison with products from Trima separator. Increase of LDH and sP-selectin in both apheresis products was comparable. CONCLUSIONS: On the basis of changes of sP-selectin and annexin V levels it could be concluded that initial platelet activation, which is induced by apheresis, is very likely without any further impact on quality of platelets during storage. Development of platelet storage lesions is influenced especially by storage conditions and platelet concentration in products.     

Biological response modifiers in photochemically pathogen‐reduced versus untreated apheresis platelet concentrates

BACKGROUND: Lipids and other biologically active substances accumulate in platelet concentrates (PCs) during storage. Some of these substances have been suggested to modulate immune responses and to play a pathogenic role in the development of transfusion‐related acute lung injury. This study compared the content and impact of some biological response modifiers in PCs treated with pathogen reduction (PR) technology and nontreated PCs. STUDY DESIGN AND METHODS: Apheresis PCs (n = 12) were split in two: one split was subjected to PR treatment (INTERCEPT, Cerus Corp.) and the other split was left untreated. Basic characterization and content of vascular endothelial growth factor (VEGF) and sCD154 were measured. Lipopolysaccharide (LPS)‐induced secretion of interleukin‐10 (IL‐10) and tumor necrosis factor‐α (TNF‐α) was measured after incubation of heparinized whole blood with platelet (PLT) supernatants. The supernatants' neutrophil (PMN)‐priming capacity, and thereby activation of the NADPH oxidase, was measured as the rate of superoxide anion production after formyl‐Met‐Leu‐Phe activation. Lipids were extracted from the supernatants on Day 6 and tested for PMN‐priming activity. RESULTS: Supernatants from PR‐treated PCs demonstrated significantly higher mean PLT volume (MPV) and O₂, lower pH, CO₂, and HCO^3?, and significantly less LPS‐induced TNF‐α secretion compared to untreated PCs. No differences in swirling, PLT count, potassium levels, glucose consumption, lactate production, IL‐10, VEGF, sCD154, or PMN‐priming activity were found between the groups over time. CONCLUSION: INTERCEPT PR treatment caused no substantial differences in PCs, except for minor changes in MPV and metabolic variables. Further studies are needed to explain the differences in the LPS‐induced TNF‐α secretion.     

Apheresis platelets: Emerging issues related to donor platelet count,apheresis platelet yield,and platelet transfusion dose

Emerging issues in stimulating apheresis platelet donors with platelet growth factors, the relative costs of apheresis and random donor platelet concentrates, optimal platelet transfusion dose, and leucoreduction of platelet products have caused renewed debate regarding apheresis products vs. random, pooled concentrates. The future role of apheresis products in platelet transfusion therapy will in large part be determined by costs, which are increasingly recognized to be influenced by donor platelet count, apheresis yield, and platelet transfusion dose. J. Clin. Apheresis 13:114–119, 1998. © 1998 Wiley-Liss, Inc.     

Quantitation of coated platelet potential during collection, storage, and transfusion of apheresis platelets

BACKGROUND: Coated platelets (PLTs), a subpopulation of PLTs observed upon dual agonist stimulation with collagen and thrombin, are known to retain several procoagulant α‐granule proteins on their surface. By formation of a highly active membrane‐bound prothrombinase complex, these PLTs represent an important step in the coagulation cascade as a consequence of their ability to generate thrombin at the site of vascular injury. Various clinical observations suggest that higher levels of coated PLTs are associated with thrombosis while a deficiency of coated PLTs results in a bleeding diathesis. Current quality control guidelines for in vitro PLT storage measure PLT viability but no routine evaluation of the hemostatic function of stored PLTs and particularly no estimation of coated PLT potential is performed. Our primary objective was to evaluate if the process of apheresis and storage of PLT units alters the levels of coated PLTs. In addition, we sought to determine how transfusion of stored PLTs into patients with thrombocytopenia affects the patient's coated PLT levels. STUDY DESIGN AND METHODS: Coated PLT levels were analyzed in 13 voluntary PLT donors before donation, in the fresh apheresis product (Trima, CaridianBCT) and in the stored apheresis product just before transfusion. In addition, 10 patients with thrombocytopenia were analyzed for coated PLTs before and after transfusion of a stored PLT product. RESULTS: Coated PLT levels were significantly decreased after the process of apheresis (17% relative decline; p < 0.01) and with prolonged storage (1 to 5 days; 53% relative decline; p < 0.001). Transfusion of stored PLT units did not result in significant increment of coated PLT levels in patients with thrombocytopenia as expected considering the low level of coated PLTs in stored PLT units. Furthermore, there was no suggestion of regeneration of coated PLT potential upon reinfusion. CONCLUSIONS: Isolation and storage of apheresis PLTs by standard blood bank procedures results in a significant decline in coated PLT potential. Reinfusion of stored apheresis PLTs into patients with thrombocytopenia resulted in a predictable change in coated PLT potential with no suggestion of regeneration of lost coated PLT potential.     

White cell subsets in apheresis and filtered platelet concentrates

BACKGROUND: White cell (WBC)-reduced platelet concentrates (PCs) are defined by their absolute WBC count, a criterion which provides no information regarding the various WBC subsets contained in the PC. These heterogeneous cells are known to mediate different physiologic and pathophysiologic functions and account for distinct adverse transfusion responses. This study describes a method which allows the detection and quantification of these subsets and characterizes their presence in a variety of platelet components. STUDY DESIGN AND METHODS: Random-donor pooled PCs (RD PCs) and single-donor apheresis PCs (SD PCs) were studied. RD PCs consisting of 6 units of 2- to 3-day old PCs were randomly assigned to be filtered with one of four WBC-reduction filters from three different manufacturers (n=34). The residual WBCs were pelleted by centrifugation and isolated on a density gradient. The various WBC subsets were quantified by flow cytometry in unfiltered and filtered PCs using fluorescence and two-angle light scatter. SD PCs obtained with two manufacturer's systems and three processing protocols (n=30) were studied in like manner. RESULTS: WBC counts for non-WBC- reduced PCs averaged 3 × 10(8) in RD PCs and ranged from 8.6 to 9.6 × 10(6) per SD PC. Residual WBC counts in filtered PCs ranged from 2.3 × 10(4) to 2.2 × 10(5) and those in WBC-reduced SD PCs averaged 2.2 × 10(5) per unit. The data demonstrate significant phenotypic differences among PCs produced with various procedures. All SD PCs and two of four filtered RD PCs contained five WBC populations including granulocytes and monocytes, while RD PCs filtered with the remaining manufacturer's devices contained only lymphocytes. CONCLUSION: The data confirm that distinct phenotypic differences exist among PCs prepared with different devices and/or procedures. It is suggested that as for non-generic pharmaceuticals, the clinical benefits of these various PCs should be individually proved.     

Bacterial contamination of platelet concentrates: results of a prospective multicenter study comparing pooled whole blood-derived platelets and apheresis platelets

BACKGROUND: The GERMS Group initiated a prospective multicenter study to assess prevalence and nature of bacterial contamination of pooled buffy-coat platelet concentrates (PPCs) and apheresis platelet concentrates (APCs) by routine screening with a bacterial culture system. STUDY DESIGN AND METHODS: In nine centers overall, 52,243 platelet (PLT) concentrates (15,198 APCs, 37,045 PPCs) were analyzed by aerobic and anaerobic cultures (BacT/ALERT, bioMérieux). RESULTS: In 135 PLT concentrates (PCs; 0.26%), bacteria could be identified in the first culture (0.4% for APCs vs. 0.2% for PPCs; p < 0.001). In 37 (0.07%) of these PC units, the same bacteria strain could be identified in a second culture from the sample bag and/or the PC unit. The rate of confirmed-positive units did not differ significantly between APC (0.09%; 1/1169) and PPC units (0.06%; 1/1544). Bacteria from skin flora (Propionibacterium acnes, Staphylococcus epidermidis) were the most prevalent contaminants. Median times to first positive culture from start of incubation were 0.7 and 3.7 days in aerobic and anaerobic cultures for confirmed-positive units. With a "negative-to-date" issue strategy, most PC units (55%) had already been issued by time of the first positive culture. CONCLUSION: The rate of confirmed bacterial contamination of PC units was low. Nevertheless, clinicians must be aware of this risk. The risk of bacterial contamination does not warrant universal preference of APCs. It must be questioned whether routine bacterial screening by a culture method can sufficiently prevent contaminated products from being transfused due to the delay until a positive signal in the culture system and due to false-negative results.     

多次捐献机采血小板后献血者外周血象的变化

目的研究多次捐献机采血小板后献血者外周血象的变化情况。方法选择20名自愿捐献机采血小板达10~38次的献血者(每次间隔期为1~2个月),在首次和末次采集血小板前分别进行外周血象的检测,进行统计分析。结果多次捐献机采血小板的献血者,末次采集前外周血小板数(PLT)与首次采集前PLT、正常值均数相比,差异均无统计学意义(P>0.05),外周血中的红细胞数(RBC)、白细胞数(WBC)、血红蛋白浓度(Hb)并未发生明显的变化,但血小板分布宽度(PDW)增加,血小板平均体积(MPV)、大形血小板比例(P-LCR)下降,且差异有统计学意义(P<0.01)。结论献血可以促进骨髓的造血功能,对机体并无明显不利的影响。     

Preparation and storage of white blood cell-reduced split apheresis platelet concentrates for pediatric use

BACKGROUND: White blood cell (WBC) reduction and bacterial screening induce unacceptable product loss when platelet (PLT) concentrates (PCs) for pediatric transfusion are prepared from whole blood. The aim was to investigate PCs, WBC reduced and bacterially screened, from single-donor apheresis procedures, divided in 3 or 4 pediatric units and stored up to 5 days. STUDY DESIGN AND METHODS: PCs were collected with an apheresis machine and WBC reduced by in-process filtration. The PCs were sampled for bacterial screening and subsequently divided in 70-mL products. Initially, storage characteristics of split units in 400-mL polyvinylchloride (PVC) bags with 17 split PCs originating from five apheresis donations were studied. When a 600-mL container made of the more gas-permeable polyolefin became available, a paired comparison was performed with 9 split PCs from nine donations and with a higher-yield PLT collection procedure. RESULTS: Split PCs contained 69 x 10(9) +/- 14 x 10(9) PLTs in 69 +/- 1 mL of plasma, and storage in the PVC containers gave a pH value of 6.86 +/- 0.10 on Day 6 (mean +/- SD, n = 17). When comparing the containers, the PVC bag contained 98 x 10(9) +/- 15 x 10(9) PLTs in 72 +/- 4 mL versus 102 x 10(9) +/- 18 x 10(9) PLTs in 74 +/- 8 mL for the polyolefin bag (n = 9, not significant). This gave pH values on Day 6 of 6.12 +/- 0.50 in the PVC container, whereas pH remained acceptable in the polyolefin container: 6.85 +/- 0.10 on Day 6 (p < 0.01). CONCLUSION: PCs for pediatric use from split single-donor apheresis concentrates, WBC reduced and bacterially screened, can be stored for up to 5 days in a 600-mL polyolefin container with maintenance of good in vitro storage variables.     

Impedance aggregometric analysis of platelet function of apheresis platelet concentrates as a function of storage time

Multiple electrode (impedance) aggregometry (MEA) allows reliable monitoring of platelet function in whole blood. The aims of the present study were to implement MEA for analyzing aggregation in platelet concentrates and to correlate results with storage time and blood gas analysis (BGA). We investigated the influence of platelet counts, calcium concentrations and agonists on platelet aggregation. Samples of apheresis concentrates up to an age of 12 days were investigated by MEA and BGA. For ASPI- and TRAPtest MEA was reproducible for a platelet count of 400 per 10^?9?L and a calcium concentration of 5?mmol L^?1. Platelets at the age of 2–4 days yielded steady aggregation. Platelet concentrates exceeding the storage time for transfusion showed steady aggregation up to 10 days, but a significant decline on day 12. Weak correlation was found regarding pCO₂ and MEA as well as regarding glucose concentration and MEA. Our results indicate that MEA is applicable for evaluation of aggregation in stored apheresis concentrates. Prolonged storage seems not to be prejudicial regarding platelet aggregation. Platelet concentrates showed acceptable BGA throughout storage time. Further studies are required to evaluate the application of MEA for quality controls in platelet concentrates.     

Isolation of leukocyte-free platelets from standard platelet concentrates by centrifugation

We evaluated centrifugation techniques to isolate leukocyte-free platelets from standard platelet concentrates. Among various settings of centrifugation force and time, we found the setting at 300 X g for 10 minutes or 370 X g for 5 minutes to be efficient and reproducible for recovering sufficient quantities of platelets free of leukocytes.