Platelet viability following storage for 5 days. Influence of holding whole blood for 8 hours at 20 to 24 degrees C before concentrate preparation

Regional blood centers frequently need to hold units of whole blood at 20 to 24 degrees C for several hours after phlebotomy so that sufficient platelet concentrates can be prepared to meet the increasing need. We have evaluated the in vivo viability and in vitro properties of platelets that were prepared from whole blood drawn into citrate- phosphate-dextrose-adenine (CPDA-1) either immediately after phlebotomy or after an 8-hour hold at 20 to 24 degrees C. Platelet concentrates were stored for 5 days at 20 to 24 degrees C in polyolefin containers (PL 732, Fenwal) with end-over-end tumbler agitation. The autologous in vivo recovery (mean +/− SD) and one-half disappearance of 51Cr-labeled platelets prepared immediately after phlebotomy were 44.4 +/− 9.4 percent and 4.0 +/− 0.5 days, respectively. Platelets prepared after the delay of 8 hours showed a recovery of 44.5 +/− 8.4 percent and a one-half disappearance of 4.1 +/− 0.4 days. After 5 days of storage, platelet concentrates showed a mean pH of 7.21 +/− 0.20 when prepared immediately after phlebotomy, and of 7.22 +/− 0.15 when prepared after an 8-hour delay. Mean morphology scores were 280 +/− 33 and 302 +/− 27 for platelets from units prepared immediately after phlebotomy or after a holding period of 8 hours, respectively. Platelets underwent synergistic aggregation after 5 days of storage, independent of the length of time that the units of whole blood were held prior to centrifugation. These studies indicate that platelet concentrates prepared from units of whole blood held initially for 8 hours can be stored for 5 days at 20 to 24 degrees C and survive satisfactorily in vivo and retain in vitro characteristics.     

Preparation and storage of platelet concentrates

A technique of platelet concentrate preparation and storage is presented which permits the maximum number of viable and functional platelets to be preserved for periods of 72 hours. Although the storage conditions must be followed precisely, the method is nevertheless simple to perform and does not require specialized expensive equipment. Critical factors include: 1) preparation of the platelet concentrates with an initial centrifugation of 1000 × g for 9 minutes and a second centrifugation of 3000 × g for 20 minutes (86%+/− 1 platelet yield), 2) a storage bag composed of either Fenwal's PL-146 or McGaw plastic, 3) constant gentle mixing, 4) a 70 ml residual plasma volume, and 5) room temperature storage (22 C +/− 2). In Vivo platelet recovery after 72 hours of storage at room temperature averaged 46 per cent +/− 3 and survival was 7.9 days +/− 0.3 (81% of fresh platelet viability). The function of these platelets as measured by the correlation between bleeding time and platelet count after transfusion of pooled platelets into unimmunized, aplastic thrombocytopenic recipients was as good as that of fresh platelets. Both viability and function of concentrated platelets stored at 4 C are severely compromised.     

以海藻糖为添加剂冷藏保存血小板悬液的研究

本研究探讨以海藻糖(trehalose)为添加剂的血小板悬液冷藏保存方法。采用核素标记法检测血小板生存时间,用比浊法测定血小板聚集率,诱导剂为终浓度11.2μmol/L的ADP。采集兔心脏血,按常规方法制备浓缩血小板悬液(PCs),在悬液中加入50mg/ml的海藻糖,37℃水浴4小时后,放于4-8℃冰箱保存,冷藏12天后,测定血小板聚集功能和输入自身体内后的生存时间。结果表明:常温和冷藏储存24小时后的PC血小板聚集率分别为(75.3±9.8)%和(80.5±12.5)%;输入兔体内24、48和72小时时的血小板存活率分别为(78.1±7.9)%、(65.4±6.7)%、(57.5±7.2)%和(5.1±2.5)%、(2.8±2.0)%、(0.9±0.8)%。加入海藻糖的PC冷藏保存12天后,血小板聚集率为(77.8±9.5)%;输入体内24、48和72小时时的血小板存活率分别为(75.7±11.0)%、(67.0±8.5)%、(56.8±8.0)%,与常温保存24小时对照相比,两者相近,P值均>0.05。结论:海藻糖能保护冷藏储存的兔血小板,延长冷藏血小板在体内的生存时间,经海藻糖冷藏储存的兔血小板功能完好。     

The effect of storage on platelet morphology

Platelet concentrates were stored for one, two or three days at 4 degrees C (unagitated) or at room temperature (unagitated and linearly agitated). After washing the concentrates twice at room temperature and then incubating them for 60 minutes at 37 degrees C, the platelet morphology was investigated by scanning and transmission electron microscopy. Platelets in freshly prepared concentrates were slightly activated, indicated by some pseudopod formation. Platelets stored at 4 degrees C rapidly lost the normal discoid shape. After three days of storage their surface membranes showed extensive folding, they were slightly vacuolated, and had lost most of their granules. Incubation of cold-stored platelets at 37 degrees C did not induce return to the discoid shape. Room temperature storage resulted in reversal of the slight initial platelet activation. After three days of unagitated room temperature storage the platelets were slightly more vacuolated than those stored with agitation. Room temperature storage usually resulted in well-preserved discoid platelets; however, some agitated platelet concentrates stored at room temperature contained a high proportion of odd shaped cells. This finding could not be correlated with pH change. The failure of platelets stored at 4 degrees C to return to the discoid shape after incubation at 37 degrees C could explain their short survival following transfusion. These results also provide a morphologic correlation with the reported slightly better recovery and survival of platelets stored at room temperature with agitation compared with those stored without agitation.     

In vitro characteristics and in vivo viability of platelets contained in granulocyte-platelet apheresis concentrate

A paired prospective study was performed to compare the in vitro storage characteristics and in vivo kinetics of platelets stored in granulocyte-platelet concentrates prepared by apheresis with platelets prepared from whole blood. Platelet and granulocyte-platelet concentrates were collected from five healthy volunteer autologous donors and stored for 16 to 18 hours at 20 to 24 degrees C with and without agitation, respectively. After storage, pH, platelet count, percent release of beta-thromboglobulin, morphologic score, and percent osmotic recovery were measured. In addition, the granulocyte-platelet concentrates were assayed for total leukocyte count, release of lysozyme, and by several in vitro tests of granulocyte function. The platelets in both products were labeled with 111In oxine and infused into the donors. The pH of both products was above 6.0 at the end of storage. The units stored as platelet concentrates compared with those stored as granulocyte-platelet concentrates showed a higher percent release of beta-thromboglobulin, 18.4 +/- 4.0 percent versus 5.9 +/- 3.2 percent (mean +/- SD), but significantly better morphologic scores, 676 +/- 21 versus 525 +/- 56, and better osmotic recovery scores, 72 +/- 10 percent versus 40 +/- 7 percent, respectively (all p less than 0.05). The platelet concentrates (compared with the granulocyte-platelet product) had significantly better in vivo recovery, 49.5 +/- 15.8 percent versus 38.9 +/- 11.5 percent, and survival, 6.1 +/- 1.3 days versus 2.4 +/- 0.4 days, respectively (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

An in vivo comparison of CPD and CPDA-2 preserved platelet concentrates after an 8-hour preprocess hold of whole blood

To see if citrate-phosphate-dextrose-adenine-two (CPDA-2) anticoagulant- preservative had an effect on the viability of platelets, we studied autologous in vivo recovery and survival in humans for platelet concentrates prepared from six units of blood drawn into CPDA-2 and compared them to six units drawn into citrate-phosphate-dextrose (CPD). These units were prepared from whole blood held at room temperature for 8 hours after collection and were then stored for 3 days at 22 ± 2 degrees C. The recovery for platelets preserved in CPD was 39.0 +/0 4.8 percent and for platelets preserved in CPDA-2, 32.5 ± 4.4 percent. The difference was not significant (p greater than 0.10). In order to estimate population differences, in vitro effects on in vivo viability were also evaluated. Six in vitro variables were studied but only pH at 72 hours (r = 0.77), platelet count (r = 0.64), and morphology score (r = 0.66) correlated to recovery. Only pH at 72 hours significantly influenced recovery (p = 0.007). By adjusting for individual pH differences, mean recovery for platelets stored in CPD was 37.5 percent, and for platelets stored in CPDA-2, 34.0 percent. The mean lifespan was 6.7 ± 0.7 days for platelets preserved in CPD and 6.1 ± 1.0 days for those preserved in CPDA-2. Although hemostatic function was not studied, these data support in vitro observations that platelets preserved with CPDA-2 are not different from platelets preserved with CPD, even after 8-hours of storage of whole blood at room temperature prior to platelet concentrate preparation.     

Seven-day storage of single-donor platelets: recovery and survival in an autologous transfusion study

BACKGROUND: Bacterial screening may effectively reduce the morbidity and mortality risk associated with extended storage of platelets. Platelet viability then becomes the primary determinant of acceptable storage time. This study evaluates the effectiveness of platelets stored in plasma for 7 days. STUDY DESIGN AND METHODS: WBC-reduced, single-donor platelets (n = 24) were collected and stored by standard methods at two sites. Standard in vitro platelet biochemical and functional parameters were monitored over the storage period. On Days 5 and 7 of storage, platelets were alternately labeled with 51Cr and (111)In and returned to the subject, and recovery and survival were determined. RESULTS: Component pH(22 degrees C) was maintained in the range 6.2 to 7.61 through 7 days and did not detrimentally affect either in vitro or in vivo outcomes. In vitro platelet characteristics were adequately maintained over 7 days. Day 5 platelets had better recovery (63.0 +/- 4.36 vs. 53.9 +/- 4.36%, p < 0.0001) and survival (161 +/- 8.1 vs. 133 +/- 8.1 hr, p = 0.006) than Day 7 platelets adjusting for radioisotope, center, and donor effects. CONCLUSION: Although declines in recovery and survival were noted, these are less than used previously to gain licensure of 7-day storage and are unlikely to be clinically significant. Extension of storage to 7 days could be implemented with bacterial screening methods to select out contaminated components without a significant effect on the platelet efficacy compared to 5-day components.     

Recovery of in vitro functional activity of platelet concentrates stored at 4 degrees C and treated with second-messenger effectors

BACKGROUND: The potential for bacterial contamination limits the storage of platelets at 22 degrees C to 5 days. Refrigerated storage at 4 degrees C would abrogate this problem but would also result in a rapid loss of in vitro viability and functional activity and in vivo viability. The inhibition of platelets during storage by a combination of specific, reversible, second-messenger effectors has been investigated to allow prolonged storage at 4 degrees C with significant retention of in vitro viability and functional activity. STUDY DESIGN AND METHODS: The combination of effectors was added directly to platelet concentrates, and this step was followed by storage at 4 degrees C. Control units were incubated at 4 degrees C without the effectors and at 22 degrees C according to standard blood-banking techniques. At 1, 5, and 9 days, the units were tested for recovery of cell number, recovery of in vitro functional activity and viability, and expression of platelet surface markers. RESULTS: Treated platelets stored at 4 degrees C for 9 days, while spherical in shape, displayed no loss of cell number and had a recovery of viability and functional activity, as compared with control platelets stored at 22 degrees C for 5 days, as follows: ADP and collagen aggregation responses of 250 and 100 percent, respectively; a 70-percent recovery of hypotonic shock response; and a 60-percent recovery of extent of shape change. The treated platelets also expressed an equivalent amount of the surface marker glycoprotein lb and a lower amount of the activation marker alpha-granule membrane protein-140 on the membrane surface. CONCLUSION: Second-messenger effectors added to platelets significantly maintained in vitro functional activity with storage at 4 degrees C. In vitro analysis demonstrates the potential for extended 4 degrees C storage of platelets with numerical and functional recovery comparable to that achieved with current methods. Refrigerated storage of platelet concentrates has the potential to reduce the risk of bacterial contamination.     

Extension of platelet concentrate storage to 7 days in second- generation bags

Platelet concentrates stored for 7 days in 50 ml of plasma in both thin film and enlarged variations of the standard 5-day CLX plastic bags were evaluated for pH maintenance and in vivo viability by two laboratories working independently. 51Cr-labeled platelets were reinfused into normal volunteers at the end of storage and recovery and half-life calculated. The pH was maintained well; less than 10 percent of units fell below 6.0 at 7 days. Mean 7-day recovery for both laboratories was 43.6 +/- 11.6 percent in the thin-film bag and 45.4 +/- 8.52 percent in the enlarged bag, compared with 43.6 +/- 8.8 percent at 5 days in the 5-day plastic licensed bag. After 7 days storage the half-life was 3.6 +/- 0.9 days in the thin-film bag and 3.7 +/- 0.6 days in the enlarged bag, compared with 3.6 +/- 0.5 days in the previously licensed CLX plastic bag after 5 days. Thus, platelet viability was maintained well at 7 days of storage in both of the container variations that allowed increased gas exchange.     

Effects of the addition of second-messenger effectors to platelet concentrates separated from whole-blood donations and stored at 4 degrees C or -80 degrees C

BACKGROUND: Platelet concentrates (PCs) are currently stored at 22 degrees C under continuous agitation. Because of the potential risk of the overgrowth of bacteria in case of contamination, PC shelf life is limited to 5 days. A mixture of second-messenger effectors is being evaluated to determine if it has benefits for cold liquid storage and cryopreservation of platelets. STUDY DESIGN AND METHODS: PCs separated from whole-blood donations by the buffy coat method were randomly assigned (n = 6 each) to be stored for 5 days at 22 degrees C under continuous agitation or at 4 degrees C after treatment with a platelet storage medium (ThromboSol, LifeCell Corp. ). PCs were also cryopreserved with 6-percent DMSO (final concentration) or with ThromboSol plus 2-percent DMSO (final concentration) (TC). After storage, platelets were analyzed by flow cytometry, transmission electron microscopy, and aggregation and perfusion techniques. RESULTS: Cold liquid storage of ThromboSol-treated platelets resulted in a lower binding of coagulation factor Va on the platelet surface than on platelets stored at 22 degrees C. In transmission electron microscopy, a conversion to spherical morphology was seen in the case of cold liquid storage. No difference between ThromboSol-treated platelets stored at 4 degrees C and platelets stored at 22 degrees C was seen in perfusion studies. Cryopreservation in the presence of TC prevented the reduction in glycoprotein Ib and IV expression on platelet surface that is seen in 6-percent DMSO-cryopreserved platelets. Platelets cryopreserved in TC covered, by thrombus, a significantly greater percentage of the perfused surface after the freezing and thawing process. CONCLUSION: ThromboSol-treated PCs separated from whole-blood donations by the buffy coat method, stored at 4 degrees C for 5 days, or cryopreserved in the presence of TC, maintained in vitro functional activity comparable to that achieved by current methods of storage, although discoid morphology was not preserved during cold liquid storage with ThromboSol.     

Sequestration of serotonin in stored platelets

A high-pressure liquid chromatographic procedure was used for the determination of 5-hydroxytryptamine (serotonin, 5HT) in platelets. The method, which is based on the separation on a reverse-phase column and measurement of native fluorescence in an acidified mobile phase, had a detection limit of femtomol quantities of 5HT. The mean contents of 5HT extracted from the Triton X-100-lysed platelets in random-donor platelet concentrates (PCs) were 0.39 +/- 0.19 mumol per 10(11) platelets (n = 5), the value of which was almost equal to 0.40 +/- 0.09 mumol per 10(11) platelets (n = 15) of platelets prepared by cytapheresis. The fate of platelet 5HT during storage of PCs at 22 degrees C with agitation was investigated for 5 days. Nearly all amounts of 5HT were sequestered within platelets after 5-day storage. No increased amounts of major metabolites of 5HT, 5-hydroxytryptophol and 5-hydroxy-3-indoleacetic acid, were detected in plasma. These data suggest that 5HT stored in dense granules of platelets is not metabolized during storage of PCs at 22 degrees C for 5 days.     

Neutrophil preservation: the effect of short-term storage on in vivo kinetics.

A rabbit model was developed to study the in vivo viability of neutrophils stored in vitro for up to 72 h. Acid-citrate-dextrose anticoagulated whole blood was obtained from rabbits previously injected with tritiated thymidine ([3H]thymidine), stored under varying conditions, and then injected into recipient rabbits. Neutrophil viability and function were assessed by measuring the ability of the tagged neutrophils to circulate and to migrate into subcutaneous polyvinyl sponges. Unstored neutrophils disappeared exponentially from the circulation with a t1/2 of 3.2 h and gave a zero time recovery of 30.5%. Storage of cells at either room temperature or 4 degrees C for 24 h or longer resulted in temporary sequestration of cells from active circulation. With cells stored for up to 72 h at 4 degrees C, recovery returned to normal values after 1-2 h. Room temperature stored cells, in contrast, showed evidence of irreversible damage at 48-h storage with low recovery for the entire time span studied. With unstored blood, 8.1+/-0.9% of the injected neutrophil label was present in the subcutaneous sponges. The accumulated label progressively decreased as cell storage time increased reaching at 72 h 5.1+/-0.6 and 2.6+/-0.3% for 4 degrees C and room temperature-stored cells, respectively. The results of this study indicate that 4 degrees C storage of rabbit neutrophils is superior to storage at room temperature. The data suggest that it may be feasible to store neutrophils at least a few days without loss of in vivo functions.     

In vitro function and in vivo viability of stored platelet concentrates. Effect of a secondary plasticizer component of PVC storage bags

Previous studies have shown that CL-2399 (Cutter) and PL-130 (Fenwal) polyvinyl chloride (PVC) plastic bags are unsatisfactory for storage of platelet concentrates (PC) at 22 degrees C. In an effort to explain the effects of plastic bags, the chemical make-up of CL-2399 and PL-130 PVC films was determined and compared with that of P1-146 (Fenwal) PVC, which is satisfactory for PC storage at 22 degrees C. The only significant difference between the three materials was the incorporation of tetrahydrofurfuryl oleate (THFO) as a secondary plasticizer in CL-2399 and PL-130. The response of platelets to aggregating agents, uptake of serotonin, recovery from hyptonic stress, and serotonin release during storage following storage in a modified CL- 2399 plastic prepared without THFO and designated CL-3000 (Cutter) was equivalent to PL-146 and far superior to CL-2399. In vivo studies in two laboratories of platelets stored in CL-3000 bags showed satisfactory recovery (56 +/− 4.2% and 46.7 +/− 2.7%) and survival (6.4 +/− 0.4 days and 7.4 +/− 0.6 days). From these studies we conclude that the THFO secondary plasticizer component of PL-130 and CL-2399 is the cause of the poor platelet viability of platelets stored in these plastic bags. The mechanism of impairment is not known. The causative agent(s) may be degradation products of THFO (formed during manufacture of the PVC film) that are leached from the plastic into PC during storage.     

Storage of buffy coat-derived platelets in additive solutions: in vitro effects of storage at 4 degrees C

BACKGROUND: The aims of this in vitro study were to compare the storage of platelets (PLTs) at 4 degrees C with those stored at 22 degrees C and to determine the in vitro effects of preincubation at 37 degrees C for 1 hour before the analysis on the basis of the maintenance of PLT metabolic and cellular integrity. STUDY DESIGN AND METHODS: PLT concentrates (PCs) were prepared from pooled buffy coats (BCs) for paired studies (total eight pools from 160 BCs). Each pool was divided into four PCs and stored under different conditions: at 20 to 24 degrees C on a flatbed agitator, at 20 to 24 degrees C on a flatbed agitator and with incubation of the samples at 37 degrees C for 1 hour before the analysis, at 4 degrees C, and at 4 degrees C and with incubation of the samples at 37 degrees C for 1 hour before the analysis. RESULTS: Storage of PLTs at 4 degrees C resulted in reductions in the rate of glycolysis and better retention of pH after Day 10 than in PCs stored at 22 degrees C (Day 14, 7.003 +/- 0.047 vs. 7.201 +/- 0.146). Hypotonic shock response and extent of shape change were higher at 22 degrees C than at 4 degrees C and in preincubated PCs stored at 22 degrees C than in reference PCs stored at the same temperature (Day 5, 45.6 +/- 2.7 vs. 36.5 +/- 3.9 and 24.1 +/- 2.0 vs. 15.5 +/- 1.8). The concentration of RANTES was higher in PCs stored at 22 degrees C than at 4 degrees C (Day 7, 179 +/- 25 vs. 79 +/- 32). CONCLUSION: PLTs stored at 4 degrees C without agitation maintain metabolic and cellular characteristics to a great extent during 21 days of storage. These studies confirm the view that PLTs lose their discoid shape and that this loss with storage at 4 degrees C is associated with reductions in metabolic rate and in their release of alpha-granule content.     

Serotonin uptake at 22 degrees C of stored platelets

In order to ascertain the possibility that platelet serotonin uptake may occur during storage of platelet concentrates (PC) at 22 degrees C with agitation, the high-performance liquid chromatographic procedure was applied to determine serotonin uptake by platelets. Studies at 22 degrees C showed that platelets stored for 4 days exhibited a significant serotonin uptake with a Vmax value of 2.4 X 10(-19) mole/platelet/min and a Km value of 0.62 X 10(-6) M. Incubation of PC with 5 X 10(-6) M serotonin for 1 day at 22 degrees C increased their serotonin contents from 2.2 to 4.2 X 10(-7) mole/10(11) platelets. Thrombin stimulation caused about 80% release of intracellular serotonin from fresh as well as stored platelets, which contained standard serotonin in the same amount as the original amount. These results suggest that a significant serotonin uptake of platelets might occur during in vitro storage at 22 degrees C and stored platelets have retained abilities to sequester extracellular serotonin into dense granules.     

Properties of platelet concentrates prepared after extended whole blood holding time

Extension of the maximum holding time for whole blood collected into a CPD-ADSOL system from 6 to 8 hours at ambient temperature under conditions that cause the temperature of the blood to decrease to 20 to 24 degrees C would facilitate the preparation of platelet concentrates (PCs). In this study, the properties of CPD-PCs prepared and stored for 5 days in PL-732 containers after various initial holding periods were assessed in two laboratories, designated Laboratory A and Laboratory B. Laboratory A found higher platelet-rich plasma (PRP) volumes (276 +/- 25 vs. 249 +/- 19 mL) and platelet yields (76 +/- 18 vs. 66 +/- 18 x 10(9) platelets) with 8-hour holds (n = 10) than with 1- to 2-hour holds (n = 10), although only the difference in PRP volumes was significant (p less than 0.05). No significant difference was observed in autologous in vivo recovery (54 +/- 11 vs. 47 +/- 9%) or survival (167 +/- 37 vs. 170 +/- 25 hrs), as calculated by gamma function using 111In as radiolabel. Laboratory B also found higher PRP volumes (304 +/- 31 vs. 279 +/- 37 mL) and platelet yields with 8-hour holds (n = 12) than with a 6-hour holds (n = 10) (88 +/- 26 vs. 77 +/- 27 x 10(9) platelets). No significant differences were found in morphology score, the extent of release of beta-thromboglobulin, the discharge of lactate dehydrogenase, or hypotonic shock response.(ABSTRACT TRUNCATED AT 250 WORDS)     

Platelet storage for 7 days in second-generation blood bags

Plastic storage bags designed to optimize O2 and CO2 transfer to preserve platelets for 7 days prior to transfusion were studied in vivo and in vitro. Platelets stored 7 days in second-generation CLX bags were compared to platelets stored 3 days in standard (CL-3861) 3-day storage bags and platelets transfused within 24 hours of collection. The CLX bags maintained concentrate pH at a mean of 6.85 +/- 0.03 (SEM) after 7 days, while in standard bags after 3 days of storage, the mean pH was 6.46 +/- 0.03. A smaller proportion of platelets stored 7 days in CLX bags were discarded because of a pH less than 6.0 compared to those stored 3 days in CL-3861 bags (10 vs 21%). Poststorage pH showed strong correlation with concentrate platelet count and weak correlation with concentrate white cell count in both bag types. There was no significant difference in the mean corrected platelet count increments between platelets stored 7 days in second generation CLX bags and those stored 3 days in CL-3861 bags (10,000 and 12,200 at 1 hour, and 7000 and 7500 at 24 hours, respectively) following transfusion to 16 thrombocytopenic recipients. However, transfusion of fresh platelets achieved mean corrected increments at both 1 and 24 hours posttransfusion that were higher than seen with either group of stored platelets (20,100 at 1 hour and 10,800 at 24 hours). Platelets can be stored 7 days in second-generation CLX blood bags with results comparable to those of platelets stored 3 days in standard bags.     

血小板保存3天后再冷冻保存的实验研究及临床应用

本研究探讨血小板常温保存3天后再进行-80℃冰箱内冷冻保存及临床应用的可行性。对当天冷冻和保存3天后再冷冻血小板进行了计数，并检测聚集力、黏附力以及CD62p的表达，并通过可对比性病例观察保存3天后再冷冻与当天冷冻血小板，临床应用的可能性。结果表明：在保存期3天之内血小板数量、低渗性休克反应、黏附功能无显著差异性改变（P〉0．05），但聚集功能和CD62p的表达率的变化有显著性差异（P〈0．05）。当天保存并冷冻的血小板与保存3天后再冷冻的血小板各项指标的变化都无显著性差异。CD62p的再表达率（CD62p凝血酶激活后阳性率-CD62p激活前的阳性率）也无显著性差异，分别是51．1±4．5和51．1±4．4（P〉0．05）。临床应用当天冷冻和保存3天后再冷冻血小板的CCI值分别是48％和49％，无显著性差异（P〉0．05）。结论：血小板保存3天后可以再-80℃冷冻保存，其临床应用效果与当天冷冻血小板比较后无明显差异。     

Seven-day storage of apheresis platelets: report of an in vitro study

BACKGROUND: The objective of this study was to determine the allowable platelet content limits for apheresis platelets stored for 7 days in a platelet storage bag (COBE ELP, Gambro BCT). METHODS: Apheresis platelets under controlled concentration and volume per bag were stored in plasma up to 8 days at 22 degrees C with horizontal agitation. Routinely evaluated in vitro platelet parameters were followed. Oxygen consumption was directly measured with a Clark-type electrode. All components were cultured in aerobic medium on Day 7. RESULTS: Twenty-four components were evaluated in storage configurations (median [range], 340 [110-402] mL, 1.32 [0.99-2.45] x 10(6) platelets/microL, and 4.8 [1.4-5.9] x 10(11) platelets/bag). No bacterial contamination was detected. One component had a pH value at 22 degrees C of below 6.0 before Day 5 with attendant loss of all other in vitro function measures. The pH value at 22 degrees C was maintained above 6.2 for the remaining 23 components. A pH value of greater than 7.4 was observed at some point in storage for 13 of 23 units, although platelet function or activation was not adversely affected. Aerobic metabolic function was maintained over 7 days with O2 consumption of 321 micromol per hour per 10(12) platelets on Day 7. CONCLUSION: Although a continuing decline of platelet in vitro characteristics can be observed for storage beyond 5 days, apheresis platelets in plasma stored 100 to 400 mL per bag, 1.0 x 10(6) to 2.5 x 10(6) platelets per microL, and a maximum of 5.1 x 10(11) platelets per bag maintained in vitro platelet characteristics over 7 days of storage.     

Extended storage of platelets in a new plastic container. II. In vivo response to infusion of platelets stored for 5 days

A new blood container material (PL 1240 plastic) made of polyvinyl chloride containing a tri(2-ethylhexyl) trimellitate plasticizer was evaluated in three laboratories. When platelet concentrates (50-60 ml) were stored on a variety of agitators for 7 days at 22 +/- 2 degrees C, poststorage pH (mean +/- SD) ranged from 7.29 +/- 0.05 (6 rpm elliptical rotator) to 6.87 +/- 0.8 (70 cycles per minute flatbed agitator). The platelet counts ranged from 1.51 +/- 0.12 to 0.95 +/- 0.36 X 10(6) per microliter. Morphology scores and hypotonic shock response values of platelets stored 7 days in PL 1240 plastic containers were better than those noted following 3-day storage of control platelets in PL 146 plastic containers. The percent discharge of lactic dehydrogenase from platelets stored 7 days in PL 1240 plastic containers for 3 days (p less than 0.05). Mean platelet recoveries of 44 +/- 15 percent (n = 11; 111Indium) and 39 +/- 8 percent (n = 29; 51Chromium) were seen when autologous platelets were infused following 5-day storage in PL 1240 plastic bags. Platelet half-lives of 3.6 +/- 0.4 (n = 9) 4.1 +/- 0.4 (n = 20) days were reported in the two laboratories which used 51Cr labeling, while survival values of 7.0 +/- 1.0, 2.8 +/- 0.8, and 5.4 +/- 1.9 days were seen when data from the 111Indium studies (n = 11) were analyzed using linear, exponential, and multiple hit programs, respectively. Platelets stored for 5 days also were administered to 13 thrombocytopenic oncology patients.(ABSTRACT TRUNCATED AT 250 WORDS)