Recovery, lifespan, and function of CPD-Adenine (CPDA-1) platelet concentrates stored for up to 72 hours at 4 C

We studied the in vivo recovery, lifespan, and hemostatic effectiveness of CPDA-1 platelet concentrates stored for up to 72 hours at 4 C. A total of 120 CPDA-1 concentrates containing an average (+/− 1 S.D.) of 6.6 +/− 2.0 × 10(10) platelets were prepared. The pH of the units following storage at 4 C was 6.8 +/− 0.2; no unit had a pH below 6.3. Autologous transfusion of six normal volunteers showed that platelets stored at 4 C for 72 hours had an in vivo recovery of 40 +/− 18 per cent and a lifespan of 5.1 +/− 1.5 days. The hemostatic effectiveness of CPDA-1 platelets was determined by platelet counts and template bleeding time measurements in 10 thrombocytopenic patients. Patients receiving 48-hour-stored platelets had a four- to six-hour posttranfusion corrected platelet increment averaging 15,300 +/− 3,200/microliter which was 67 +/− 34 per cent of expected recovery. Four of the five patients transfused with this preparation showed an improved bleeding time. In contrast, three patients receiving 72-hour- stored platelets had a four- to six-hour posttransfusion increment of 5,800 +/− 2,400/microliter that was only 26 +/− 13 per cent of the expected recovery; furthermore, only one of these patients showed any correction of the bleeding time. These data indicate that CPDA-1 platelets are hemostatically effective when stored at 4 C for up to 48 hours.     

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.     

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.     

Treatment of refractoriness to platelet transfusion by protein A column therapy

Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

Circulation and function of human platelets isolated from units of CPDA- 1, CPDA-2, and CPDA-3 anticoagulated blood and frozen with DMSO

Platelet concentrates (PC) were isolated by serial differential centrifugation from units of blood anticoagulated with one of the citrate-phosphate-dextrose-adenine solutions (CPDA-1, CPDA-2, CPDA-2). The platelet concentrates were frozen with six percent dimethylsulfoxide at 2–3 degrees C per minute and stored in a -80 degrees C mechanical freezer in polyvinyl chloride or polyolefin plastic containers. After frozen storage at -80 degrees C for up to three months, the concentrates were thawed at 42 degrees C within 2.5 to 4.0 minutes, washed with autologous plasma, two percent dimethylsulfoxide and 10 percent acid-citrate-dextrose solution, and then resuspended in plasma. The washed platelets were labeled with 51Cr and transfused back to the donor from whom they had been obtained. In vitro recovery from whole blood to platelet concentrate was 70.5 ± 17 percent (mean ± one SD). In vitro freeze-thaw-wash recovery determined by phase microscopy was 78.5 ± 12.8 percent, in vivo 51Cr platelet recovery two hours after transfusion was 41.3 ± 13.5 percent, and the platelets had a linear lifespan of about eight days. A single unit of previously frozen platelets shortened an aspirin- prolonged bleeding time two and 24 hours after infusion. Results were similar with platelets isolated from all three anticoagulants and stored in both plastics. The results also were comparable to previous findings in this laboratory with platelets isolated from ACD and CPD anticoagulated blood.     

In vitro evaluation of platelets stored in CDP-adenine formulations

Little information is available about the effect of adenine and added glucose on stored platelets. Two new formulations, CPDA-2 and CPDA-3, contain 34 mg adenine per 63 ml preservative and extra glucose (1.75 and 2.0 times the glucose in standard CPD). We have studied the in vitro integrity of platelet concentrates stored in CPD, CPDA-1, CPDA-2, and CPDA-3 at 22 C for 72 hours. Morphology score, pH, platelet size, population distribution parameters, and electron microscopic ultrastructure did not show any adverse effects which could be ascribed to the presence of adenine or extra glucose or both. No differences in platelet adenosine triphosphate (ATP) concentration or plasma glucose utilization during storage were found between CPD and CPDA-1 platelets. The results suggest that adenine and added glucose in these preservatives are not detrimental to platelets in vitro by the measures employed.     

The in vivo survival of red blood cells stored in modified CPD with adenine: report of a multi-institutional cooperative effort

In order to provide data in support of licensure applications for citrate-phosphate-dextrose (CPD) supplemented with adenine, a multi- institutional cooperative effort was organized to determine survivability of red blood cells subjected to prolonged liquid storage. Two manufacturers supplied plastic multiple bag blood storage containers prefilled with modified CPD (glucose 25/ greater than the normal concentration) supplemented with adenine (17.0 to 17.3 mg per 63 ml of anticoagulant; 0.25 millimolar approximate final concentration when diluted with 450 ml of whole blood for 35 days showed a mean survival of 80.53 +/- 6.44 per cent (1 SD). Both red blood cell and supernatant plasma biochemical characteristics were comparable to those reported for whole blood stored for 21 days in either acid-citrate- dextrose (ACD) or CPD. Red blood cells from 19 units stored as concentrates for 35 days (Hct 75.03 +/− 3.74%) had a mean survival of 71.38 +/− 10.3 per cent with considerable interdonor variation in survival and interlaboratory variation in some biochemical characteristics. Red blood cells from eight units stored as concentrates (Hct 75.38 +/− 4.30%) for 28 days showed a mean survival of 83.97 +/− 6.10 per cent and biochemical characteristics comparable to those reported for red blood cell concentrates stored in CPD or ACD for 21 days. Modified CPD with adenine as formulated offers an improved anticoagulant for blood banking by extending the permissible red blood cell storage period.     

Effect of storage time on clinical efficacy of single-donor platelet units

Decrements in platelet function and recovery are known to accumulate during the 5-day storage period, and the clinical response to platelets transfused after several days' storage has been suggested by some researchers to be less than that seen with platelets stored for shorter periods. The clinical response to single-donor platelet (SDP) units (as measured by corrected count increments [CCIs] and intertransfusion intervals) was investigated in autologous bone marrow transplant patients. Twenty-seven consecutive autologous bone marrow transplant patients with a variety of hematologic and solid organ malignancies were evaluated for posttransfusion CCIs after 419 SDP transfusions of units stored for 1 to 5 days. Patients were not excluded from the study because of clinical condition, such as fever or sepsis. The mean 15- minute posttransfusion CCI for SDP units stored for only 1 day (11,006 +/− 5,157) was no different than that for units stored for 5 days (10,225 +/− 4,481; p > 0.05); 24-hour posttransfusion CCIs were also not different if the SDP unit had been stored for 1 day or 5 days (6229 +/− 4489 vs. 4786 +/− 2759; p > 0.05) or for any intermediate period. Nor were intertransfusion intervals affected by storage time. While platelets may exhibit a progressive lesion during the 5-day storage period, these changes do not result in a decreased clinical response.     

Platelet concentrates stored for 5 days in a reduced volume of plasma maintain hemostatic function and viability

BACKGROUND: Platelet concentrates prepared from whole blood are generally suspended in a standard volume of 50 to 60 mL of plasma and can be stored thus at 20 to 24 degrees C for up to 5 days. In vitro studies suggested that this plasma volume could be reduced to 30 to 35 mL without impairing platelet function. STUDY DESIGN AND METHODS: This study evaluated whether platelets stored for 5 days in a reduced volume (30-35 mL) of plasma maintained their in vivo viability, hemostatic function, and recovery in recipients. Paired autologous platelet survival studies were done in 20 adult volunteers to assess platelet viability. A rabbit ear bleeding-time model was used to compare the hemostatic effectiveness of human platelet concentrates stored for 5 days in the standard or reduced volume of plasma. Platelet recovery was compared in thrombocytopenic hospital patients. RESULTS: Paired platelet survival studies indicated no significant difference between the values in platelet concentrates stored for 5 days in the reduced volume of plasma and the values in those stored in the standard volume. In the animal model, there was no significant difference in the bleeding times achieved by either set of platelet concentrates. The platelet count increments in thrombocytopenic patients were measured. The platelet count increments in patients who received reduced-volume platelet concentrates were as good as the increments achieved in patients given standard-volume concentrates. CONCLUSION: The in vivo viability, recovery, and hemostatic function of platelets collected in polyvinylchloride plastic containers and stored in 30 to 35 mL of plasma for 5 days are maintained as well as those of platelets stored in 50 to 60 mL of plasma.     

Assessment of the correlation of platelet morphology with in vivo recovery and survival

BACKGROUND:  There is continuing interest in the development of in vitro tests evaluating the in vivo function, recovery, and survival of platelets stored for transfusion. A recent forum concluded that no completely reliable test exists, although discoid morphology indicates a platelet's good health. We evaluated a novel device, the NAPSAC (Noninvasive Assessment of Platelet Shape and Concentration), designed to determine noninvasively the proportion of discoid platelets in a stored concentrate, as well as platelet concentration.
STUDY DESIGN AND METHODS:  Twenty-eight plateletapheresis concentrates stored 24 hours in PL-146 were evaluated. Percent discoid platelet results were correlated with radiolabeled autologous recovery and survival performed using 111Indium oxyquinoline and calculated using linear (L) and multiple-hit (M) models. pH of 8 concentrates was raised at the end of storage with 6N NaOH. Platelet concentration measured by NAPSAC and Coulter Thrombocounter C was compared in 256 plateletapheresis products.
RESULTS:  Percent discoid platelets at 24 hours did not correlate significantly with platelet recovery or survival (recovery L = 0.29, M = 0.28; survival L = 0.16, M = 0.03). Raising the pH (mean 6.38 to 6.94) resulted in a significant increase in percent discoid platelets (21% to 41%). Platelet concentration values for both methods studied were linearly correlated with a slope of 1.01 ± 0.03, r = 0.81.
CONCLUSION:  Percent discoid platelets was not predictive of posttransfusion platelet recovery or survival. The results suggest that non-discoid platelets may survive posttransfusion and even revert to discoid shape, since raising the pH approximately doubled the percent of discoid platelets. The NAPSAC was shown to be a reliable instrument for noninvasively determining platelet concentration in PL-146 concentrates.     

Ultraviolet-B irradiation of platelets: a preliminary trial of efficacy

Prior studies established that ultraviolet-B light (UVB) irradiation of platelet concentrates (PCs) at appropriate doses can eliminate the mixed lymphocyte culture-stimulating and -responding capacity of lymphocytes in the PCs without adversely affecting in vitro platelet function. The in vivo recovery and survival and in vitro characteristics of UVB-irradiated platelets were investigated in paired studies. PCs were stored for 1 day and then exposed to UVB. Platelet recovery, survival, and function were comparable to those of nonirradiated platelets. Recovery and survival of platelets stored for 5 days before UVB exposure were decreased relative to controls, although they were considered clinically acceptable. Paired transfusion studies were also performed in seven thrombocytopenic patients by using platelets obtained by apheresis. Comparable posttransfusion platelet increments and bleeding time corrections were obtained with both irradiated and control (nonirradiated) platelets. It can be concluded that platelets survive and function relatively normally in vivo after UVB irradiation sufficient to abolish lymphocyte reactivity in mixed lymphocyte culture. Long-term studies of UVB-irradiated PCs are needed to assess their potential in reducing recipient alloimmunization.     

Survival and biochemical characteristics of stored red cells preserved with citrate-phosphate-dextrose-adenine-one and two and prepared from whole blood maintained at 20 to 24 degrees C for eight hours following phlebotomy

Studies were conducted to evaluate the characteristics of red cells stored for 35 days following preparation from units of whole blood anticoagulated with citrate-phosphate-dextrose-adenine-one and two (CPDA-1 and CPDA-2) and maintained at 20 to 24 degrees C for 8 hours after phlebotomy. The mean (+/− 1 SD) 24-hour survival for transfused CPDA-1 autologous red cells with hematocrit levels of 78.1 +/− 2.3 percent was 78.0 +/− 8.1 percent (n = 9). The 24-hour survival of red cells from units preserved with CPDA-2 with hematocrit levels of 79.3 +/− 4.5 percent was 74.8 +/− 8.6 percent (n = 15). This difference in survival was not significant. Red cells from control units stored for 1 day showed a 24-hour survival of 91.9 +/− 4.2 percent (n = 7). During the 8-hour holding, red cell adenosine triphosphate levels increased by 15 to 25 percent in units drawn into both CPDA-1 and CPDA-2. After the initial 8-hour period, the red cell 2,3 diphosphoglycerate levels were 54 +/− 12 percent (mean +/− 1 SD) of initial levels in units drawn into CPDA-1 and 58 +/− 8 percent of initial levels in units drawn into CPDA- 2. Following 35 days of storage, units of red cells prepared from whole blood drawn into CPDA-1 and CPDA-2 had comparable plasma cation and ammonia levels and similar amounts of cell-free hemoglobin. These data indicate that red cells can be stored satisfactorily for 35 days when prepared from whole blood held at 20 to 24 degrees C for 8 hours.     

Obituaries

Platelet aggregation by adenosine diphosphate (ADP) is a self-limited and reversible process. An application of this phenomenon is described which allows removal of the platelets from large volumes of fresh platelet rich plasma (PRP) for the preparation of platelet concentrates. The macroscopic platelet clumps resulting from a concentration of 10 μgm ADP per ml of PRP are removed by centrifugation at 50 × g for 10 minutes. Resuspension of these platelets in 20 cc of native plasma results in a platelet concentrate that is 80 to 90 per cent as effective per unit as PRP in its ability to elevate the platelet count in recipients. Such concentrates are superior to concentrates prepared by other methods. The posttransfusion survival of ADP platelets compares favorably with the survival of platelets administered as PRP. There is evidence of minor sequestration but there is no apparent irreversible damage to platelets handled in this manner. Alkaline plasma and increase in plasma ionized calcium enhance the ADP aggregation and improve the efficiency of in vitro separation of platelets from PRP. However, the resulting concentrate is less effective in vivo, because of prolonged and slowly reversible clumping, and failure of these platelets to circulate.     

Viability and function of platelets frozen at 2 to 3 C per minute with 4 or 5 per cent DMSO and stored at −80 C for 8 months

Each of 15 healthy male volunteers was treated with 650 mg of aspirin 24 hours before the autologous transfusion of one unit of freeze- preserved platelets. Freeze-thaw-wash recovery values in vitro, viability and function in vivo, and the bleeding time and platelet aggregation response were measured. The platelets were frozen with 4 or 5 per cent dimethylsulfoxide (DMSO) at an overall rate of 2 to 3 C per minute and were stored at −80 C in a mechanical freezer for up to eight months. They were washed by dilution/centrifugation. The mean recovery in vitro of platelets frozen with 4 per cent DMSO was 76+/−16%; the value was 64+/−16% for platelets frozen with 5% DMSO. The mean in vivo 51Cr recovery of autologous platelets frozen with 4% DMSO was 34+/−6%, and for platelets frozen with 5% DMSO it was 33+/−7%. In both groups the platelet lifespan was normal. There was a significant reduction in bleeding time after the transfusion of a single unit of autologous platelets preserved with either 4 or 5% DMSO, but no improvement in the aspirin-induced platelet aggregation pattern.     

Effect of microaggregate blood filtration on platelet concentrates in vitro

In order to determine if platelet concentrate could be transfused through microaggregate filters, platelets collected in CPD and CPDA-1 preservatives were passed through the currently available microaggregate blood filters. Both clean filters and filters preloaded with two units of outdated whole blood were studied. Prefiltration and postfiltration testing included determination of platelet count, per cent maximal ADP aggregation, release of B-thromboglobulin, and morphologic examination using electron microscopy. Compared to the prefiltration values, those for postfiltration showed no significant differences (p > 0.05) for any of the microaggregate filters tested. Filtration itself did not appear to affect platelet morphology. Unlike the platelets in stored concentrates, however, a significant (p < 0.05) number of the platelets contained in fresh whole blood (27 to 45%) were removed by depth-type microaggregate filters. Platelets remaining in the filter residual volume could be readily eluted by rinsing with crystalloid or colloid solutions. Due to development of an in vitro storage lesion, platelet concentrates can be transfused through new or used microaggregate filters without loss of platelet number or changes in platelet function as measured in vitro.     

Studies of the minimum temperature at which human platelets can be stored with full maintenance of viability

Platelet concentrates from normal donors were stored for 3 days under identical conditions except for the temperature of storage, which was maintained at 21 +/- 0.5, 19.5 +/- 0.5, or 18 +/- 0.5 degrees C. Immediate posttransfusion recovery of the stored platelets determined by 51Cr labeling averaged 47, 47, and 48 percent after storage at 21, 19.5, and 18 degrees C, respectively (differences not significant). Mean life span of the transfused platelets, however, was 8.12, 5.21, and 1.85 days at 21, 19.5, and 18 degrees C, respectively. The difference between mean life span following storage at 21 degrees C was significantly different from that after storage at 18 degrees C (p less than 0.03). Reduction in viability after storage at the lower temperature correlated with the reduction in the number of discoid platelets. These findings indicate that platelet viability is compromised after storage for 3 days at 18 degrees C and, possibly, at 19.5 degrees C, and illustrate the need for quality control of temperature in short-term platelet storage.     

Platelet collection with the Amicus and the AS.TEC 204 blood cell separators

BACKGROUND: Platelet collection with two new blood cell separators was compared with respect to platelet yield, separation efficiency, white cell (WBC) contamination, and measures of component quality. Both machines offer a menu for the collection of a desired platelet yield. The harvesting of a definite platelet yield is a means of collecting a standardized therapeutic platelet dose. STUDY DESIGN AND METHODS: One hundred seventy-two platelet collections were carried out with different protocols in the two devices (Amicus and AS.TEC 204). For that reason, healthy donors underwent plateletpheresis procedures using the continuous- and discontinuous-flow systems. Separations with a definite endpoint volume and the option of collecting a desired platelet yield of 5.5 × 10(11) in the Amicus and 3.3 × 10(11) in the AS.TEC 204 machine were investigated. RESULTS: With the Amicus blood cell separator, platelet yield (5.02+/−0.46 × 10[11]) and separation efficiency (66.9+/−6.2%) were significantly higher than those with the AS.TEC 204 (3.02+/−0.62 × 10[11] and 46.4+/−6.7%, respectively). There was less deviation between the platelet yield and the desired platelet yield in the AS.TEC 204 machine than in the Amicus device. WBC contamination was 2.06+/−2.91 × 10(6) in components obtained from the AS.TEC 204 machine, and 87.5 percent of the platelet concentrates had a WBC content <5 × 10(6). None of the components from the Amicus device contained more than 5 × 10(6) WBCs. Except for platelet morphology score, measures of component quality were almost equal in the platelet concentrates obtained from the studied machines. CONCLUSION: Platelet yield and separation efficiency were significantly higher in the Amicus blood cell separator. The collection of a desired platelet yield was better achieved with the AS.TEC 204 device.     

In vivo viability of red blood cells stored in CPDA-2

The marginal viability of erythrocytes stored for 35 days as red blood cell concentrates in citrate-phosphate-dextrose-adenine-one (CPDA-1) was attributed to inadequate nutrient support with adenine and glucose. In an effort to improve the viability of red blood cells following extended storage, a new CPD-adenine and 1.4 times more glucose than CPDA-1. The efficacy of CPDA-2 was evaluated in vivo by measurement of 24-hour postinfusion recovery of 51Cr-labeled erythrocytes which had been stored as whole blood or red blood cell concentrates for 5 to 8 weeks. All red blood cell concentrates, and the whole blood units stored for 35 and 42 days, were held at room temperature for 8 hours prior to processing and/or refrigeration. CPDA-2 yielded significantly higher 51Cr survivals than CPDA-1 and exceeded the accepted criterion for anticoagulant preservative efficacy of 70 percent postinfusion survival of red blood cells after storage for a period of 42 days. Preliminary data supports possible usage to 49 days. Plasma glucose and red blood cell ATP concentration were maintained better in CPDA-2 than in CPDA-1. When compared to historical controls for CPD and CPDA-1 the data suggest that red blood cells stored in CPDA-02 will have superior viability throughout the entire storage period. CPDA-2 is a candidate to replace CPDA-1 as the anticoagulant-preservative solution of choice for red blood cell concentrates.     

Frozen autologous platelets in the supportive care of patients with leukemia

Multiple units of platelet concentrate obtained by intensive plateletpheresis of patients with leukemia in remission were pooled and frozen using 4 to 5 per cent dimethylsulfoxide and retransfused during periods of thrombocytopenia. Plateletpheresis was well tolerated by all donors and an average platelet yield per unit of 0.99 × 10(11) (n = 155) was obtained. The results of 107 transfusions to 36 patients are presented. An average of 32.4 per cent of the platelets were lost during the freeze-thaw process. Freezing loss was lowest at a freezing rate of one degree C per minute, at a lower final concentration of platelets, and when polyolefin bags were used. The mean corrected posttransfusion count increment was 6,400/mul (range 600–19,000 xm2/10(11) platelets transfused). In vivo results did not correlate with freezing rate but were statistically significantly better at lower platelet (approximately 0.16 × 10(11) platelets/10 ml) concentrations. Eleven patients, including some who were refractory to random donor platelets were supported entirely with autologous platelets during reinduction therapy for leukemia. When administered prophylactically the autologous platelets seemed to prevent hemorrhage during periods of thromobocytopenia although in most patients bleeding times were not corrected posttransfusion. This study demonstrates that frozen autologous platelets can be used in the supportive care of thrombocytopenic patients. Further technical improvements are necessary before platelet freezing becomes practical for widespread use.