[Transfusion-related acute lung injury]. / Transfusionsassoziierte akute Lungeninsuffizienz.

Transfusion-related acute lung injury (TRALI) developed into the leading cause of transfusion-related morbidity and mortality after the first description by Popovsky et al. approximately three decades ago. It was the most frequent reason for transfusion-related fatalities worldwide before implementation of risk minimization strategies by donor selection. Plasma-rich blood products, such as fresh frozen plasma and apheresis platelets seem to be the leading triggers of TRALI. Hypoxemia and development of pulmonary edema within 6 h of transfusion are the diagnostic criteria for TRALI. The differentiation between cardiac failure and other transfusion-related lung injuries, such astransfusion-associated circulatory overload ( TACO) is difficult and causal treatment is not available. Therapy is based on supportive measures, such as oxygen insufflationor mechanical ventilation. The exactly pathogenesis is still unknown but the most propagated hypothesis is the two-event-model. Neutrophils are primed by the underlying condition, e.g. sepsis or trauma during the first event and these primed neutrophils are activated by transfused leukoagglutinating antibodies (immunogen) or bioreactive mediators (non-immunogen) during the second-event. Transfusion of leukoagglutinating antibodies from female donors with one or more previous pregnancies is the most frequent reason. No more TRALI fatalities were reported after implementation of the donor selection in Germany in 2009.

No proinflammatory signature in CD34+ hematopoietic progenitor cells in multiple sclerosis patients.

Autologous hematopoietic stem cell transplantation (aHSCT) has been used as a therapeutic approach in multiple sclerosis (MS). However, it is still unclear if the immune system that emerges from autologous CD34+ hematopoietic progenitor cells (HPC) of MS patients is pre-conditioned to re-develop the proinflammatory phenotype. The objective of this article is to compare the whole genome gene and microRNA expression signature in CD34+ HPC of MS patients and healthy donors (HD). CD34+ HPC were isolated from peripheral blood of eight MS patients and five HD and analyzed by whole genome gene expression and microRNA expression microarray. Among the differentially expressed genes (DEGs) only TNNT1 reached statistical significance (logFC=3.1, p<0.01). The microRNA expression was not significantly different between MS patients and HD. We did not find significant alterations of gene expression or microRNA profiles in CD34+ HPCs of MS patients. Our results support the use of aHSCT for treatment of MS.

Transportation and cryopreservation may impair haematopoietic stem cell function and engraftment of allogeneic PBSCs, but not BM.

Recent data suggest that the practice of using frozen allogeneic grafts is becoming increasingly common among transplant centres. Therefore, we retrospectively analysed 31 frozen allogeneic PBSC and 8 BM grafts by flow cytometry with regard to their CD34+ content, membrane integrity (7-AAD) and stem cell-specific enzyme activity (aldehyde dehydrogenase, ALDH) in relation to individual transplantation results. Membrane integrity of CD34+ cells was significantly impaired in cryopreserved PBSC but not in BM compared to unfrozen allografts. In 9 out of 31 frozen PBSC (but none of the BM) grafts numbers of SSC(lo)ALDH(br) cells per kg body weight (BW) were significantly reduced while in the same grafts the numbers of CD34+ cells per kg BW were close to normal. Overall, 9 out of 33 patients (27%) who received unrelated PBSC allografts cryopreserved after transportation did not achieve engraftment. For comparison, primary graft failure was observed in our centre in only 7 out of 493 recipients (1.4%) of fresh allogeneic PBSC grafts. Moreover, we did not see any graft failure in patients receiving frozen/thawed BM or autologous PBSC transplants. We, therefore, conclude that PBSC grafts become much more sensitive to cryopreservation after transport and/or storage. Importantly, the engraftment potential of frozen HSC grafts may reliably be predicted by measuring ALDH activity.

CD34(+)-selected stem cell boost for delayed or insufficient engraftment after allogeneic stem cell transplantation.

BACKGROUND: Poor graft function without rejection may occur after stem cell transplantation (SCT). CD34(+) stem cell boost (SCB) can restore marrow function but may induce or exacerbate GvHD. We therefore investigated the feasibility and efficacy of CD34(+)-selected SCB in some patients with poor graft function. We present the results for eight patients (median age 46 years) transplanted initially for myelofibrosis, acute leukemia, myeloma and NHL. Six patients had received HLA-matched and two mismatched grafts (PB, BM; n=5, 3). After a median of 128 days post-transplant, the median leukocyte and platelet counts were, respectively, 2.05/nL and 18/nL. None had achieved platelet counts >50/nL even though donor chimerism was >95% in seven recipients. METHODS: Positive selection of CD34(+) stem cells was performed on a CliniMACS device, observing GMP and achieving a median of 98.5% purity. The patients received a median of 1.7 x 10(6)/kg CD34(+) cells and 2.5 x 10(3)/kg CD3(+) T lymphocytes. RESULTS: Hemograms at days +30, +60 and +90, respectively, showed steadily increasing median leukocyte (2.55, 3.15 and 4.20/nL) and platelet (29, 39 and 95/nL) counts. After a median follow-up of 144 days, five patients remained alive. No patient had developed acute or chronic GvHD. One patient died of leukemic relapse and two others of systemic mycosis. DISCUSSION: These preliminary results point to the possibility of safely improving graft function using CD34(+) positively selected stem cells without necessarily increasing the incidence of GvHD in patients with poor graft function post-SCT. Experience with more patients and longer follow-up should clarify the optimal role for this procedure.

Transfusion of autologous, hydroxyethyl starch-cryopreserved red blood cells.

UNLABELLED: In this prospective, randomized study, we investigated the safety and efficacy of the transfusion of hydroxyethyl starch (HES) cryopreserved red blood cells (RBC) compared with the transfusion of liquid-stored RBC in patients undergoing major orthopedic or urologic surgery. Thirty-six patients donated autologous blood 35 +/- 6 days before elective surgery. Only the first of 3.5 +/- 1.3 donated units of RBC was randomly assigned to be stored in the liquid state at 4 degrees C in phosphate/adenine/guanosine/glucose/saline-Mannitol or frozen below -130 degrees C by means of liquid nitrogen after the addition of HES (molecular weight 200,000 Dalton, degree of substitution 0.5, final concentration 11.5% wt/wt) as a cryoprotectant. After induction of anesthesia, patients donated 900 mL of autologous blood before they received one unit of liquid-stored RBC in Group 1. In Group 2, one unit of cryopreserved autologous RBC was transfused after removal of the cryoprotectant HES. In Group 3, patients received one unit of cryopreserved RBC without any manipulation after thawing. Patients in Groups 1 and 2 received additional 500 mL of 10% HES. Hemodynamic variables, arterial blood gases, plasma hemoglobin, and arterial lactate concentrations were measured after the induction of anesthesia, after hemodilution, and at 10-min intervals after transfusion of the respective RBC concentrate over a period of 40 min. Skeletal muscle tissue oxygen tension was measured in the quadriceps muscle using an automatically stepwise-driven oxygen partial pressure electrode. We found no differences among groups concerning demographics, arterial blood gas values, and lactate concentrations and observed no adverse reactions after transfusion of the conventionally stored or cryopreserved RBC. Hemodynamic variables did not differ among groups, with the exception of an increased mean arterial blood pressure after the transfusion of cryopreserved unwashed RBC. In all groups, the skeletal muscle tissue oxygen tension remained constant after hemodilution and increased after transfusion of either washed or unwashed cryopreserved RBC. Although the free plasma hemoglobin concentration remained constant after the transfusion of liquid-stored RBC (26 +/- 8 mg/dL), the plasma hemoglobin concentration increased twofold after the transfusion of cryopreserved washed RBC (60 +/- 12 mg/dL) and threefold after transfusion of cryopreserved unwashed RBC (98 +/- 20 mg/dL). The authors conclude that transfusion of one unit of RBC after cryopreservation with HES is safe and well tolerated by patients. Intravascular volume replacement and skeletal muscle oxygenation characteristics by erythrocytes did not differ between liquid-stored and cryopreserved RBC. IMPLICATIONS: This study examined whether a colloid should be used to store blood. Our data suggest that the transfusion of one unit of red blood cells after cryopreservation with hydroxyethyl starch is safe and well tolerated by patients. The effects of intravascular volume replacement and skeletal muscle oxygenation provided by red blood cells after liquid storage or cryopreservation were not different.

Cryopreservation of peripheral blood progenitor cells: characteristics of suitable techniques.

The influence of 6 different cooling rates (1.4, 5, 10, 15, 20, 160 K/min) and 5 different compositions of the suspensions to be frozen (% DMSO/% HES: 10/0, 7.5/2.5, 5/6, 2.5/7.5, 0/10) were investigated in 30 aliquots from each of 12 peripheral blood progenitor cells (PBSC) products which had been obtained by leukapheresis from 11 patients with hematological malignancies and solid tumors and 1 healthy donor treated with 5-24 micrograms/kg body weight/day granulocyte colony stimulating factor (G-CSF) over 5 days. The MNC concentration in the products obtained amounted to 4.51 +/- 1.55 x 10(7)/ml (mean +/- SEM), range: 2.10-7.65 x 10(7)/ml). For freezing, cooling rates were generated by means of a liquid nitrogen(LN2)-operated, computer-controlled freezer, a mechanical -80 degrees C freezer, in the vapor phase over LN2, and by submerging into LN2. The statistical analysis of the results clearly indicates that optimum results compared with the prefreeze values for numerical recovery (80.6 +/- 20.1%, Coulter counter), viability (membrane integrity by Trypan blue exclusion 91.6 +/- 4.1%), and colony-forming potential (56.2 +/- 45.8% erythroid burst-forming units [BFU-E], 63.4 +/- 72.8% myeloid colonies [CFU-GM]) were achieved at a cooling rate of 1.4 K/min with 10% DMSO being present. The values obtained at a cooling rate of 5 K/min (-80 degrees C mechanical refrigerator) in the presence of 5% DMSO and 6% HES did not differ significantly (i.e., membrane integrity 91.8 +/- 3.9%, BFU-E 53.0 +/- 37.4%, CFU-GM 47.8 +/- 58.2%). At cooling rates above 5 K/min and DMSO concentrations lower than 5% (in spite of higher HES concentrations) there was a significant drop of CFU recovery (CFU-GM plus BFU-E) to almost 0%. In parallel, numerical recovery and viability dropped as well, but less pronounced, indicating that both methods are unsuitable for the prediction of CFU recovery when different freezing protocols are applied. We need at least 5% DMSO (in the presence of 6% HES) in spite of the undesirable histamine-releasing effect of this compound. The cooling rate is not critical in the range from 1 to 5 K/min and can easily be achieved by -80 degrees C freezers.

Modification of activation-dependent platelet antigens CD62p and CD63 during haemodialysis.

In particular, activated platelets are thought to be involved in the pathophysiology of thrombotic occlusions of vessels. In this study, we evaluated activation-dependent changes in platelet antigens during extracorporeal haemodialysis treatment. Flow cytometry was used in combination with monoclonal antibodies that bind to platelet glycoproteins CD62p (GMP-140) and CD63 (GP53). Maximum peaks of mean channel fluorescence intensity (MCFI) were reached after 60 min in 20/26 procedures in CD62p (P < 0.005) and in 15/25 treatments in CD63 (p < 0.002), respectively. An initial peak of CD62p and CD63 fluorescence expression could be detected in 21/25 and 23/25 treatments, respectively (CD62p within 15, CD63 within 30 min), indicating the early onset of activation. The structural antigen CD41a MCFI slightly decreased over time in all treatments, while CD42b expression did not change. From these results we conclude that haemodialysis contributes to platelet activation and secondary hypercoagulability. Analysis of platelet glycoproteins by flow cytometry may provide clinical information on patients at a higher risk for thrombosis and may help in further improvement of haemodialysis equipment.

Bovine haemoglobin is more potent than autologous red blood cells in restoring muscular tissue oxygenation after profound isovolaemic haemodilution in dogs.

PURPOSE: This study compares the effects of stored red cells, freshly donated blood and ultrapurified polymerized bovine haemoglobin (HBOC) on haemodynamic variables, oxygen transport capacity and muscular tissue oxygenation after acute and almost complete isovolaemic haemodilution in a canine model. METHODS: Following randomization to one of three groups, 24 anaesthetized Foxhounds underwent isovolaemic haemodilution with 6% hetastarch to haematocrit levels of 20%, 15% and 10% before they received isovolaemic stepwise augmentation of 1 g.dl-1 haemoglobin. In Group 1, animals were given autologous stored red cells which they had donated three weeks before. In Group 2, animals received freshly donated blood harvested during haemodilution. In Group 3, animals were infused with HBOC. Skeletal muscle tissue oxygen tension was measured with a polarographic 12 mu needle probe. RESULTS: In all groups, heart rate and cardiac index were increased with decreasing vascular resistance during haemodilution (P < 0.05). Haemodynamic variables showed a reversed trend during transfusion when compared to haemodilution but remained below baseline (P < 0.05). Arterial and venous oxygen content were changed in parallel to changes of haematocrit and haemoglobin concentrations but were lower in Group 3 than in Groups 1 and 2 (P < 0.05) during transfusion. In contrast, the oxygen extraction ratio was higher in Group 3 (59 +/- 8%, P < 0.01) at the end of transfusion than in Group 1 (37 +/- 13%) and 2 (32 +/- 5%). In Group 3, mean tissue oxygen tension increased from 16 +/- 5 mmHg after haemodilution to 56 +/- 11 mmHg after transfusion (P < 0.01) and was higher than in Group 1 (41 +/- 9, P < 0.01) and Group 2 (29 +/- 11, P < 0.01). While in Group 3 an augmentation of 0.7 g.dl-1 haemoglobin resulted in restoring baseline tissue oxygenation, higher doses of 2.7 g.dl-1 and 2.1 g.dl-1 were needed in Groups 1 and 2 to reach this level (P < 0.01). CONCLUSION: The results show a higher oxygenation potential of HBOC than with autologous stored red cells because of a more pronounced oxygen extraction.

Storage of peripheral blood stem cell samples alters flow cytometric CD34+ results.

With the use of monoclonal antibodies against the CD34 antigen, flow cytometry (FC) permits rapid assessment of the quality of hematopoietic grafts. We examined PBSC samples (n = 40) to investigate possible influences of storage time and temperature on FC results. After cytapheresis, a sample of the PBSC product was collected and divided into 4 aliquots. Immediate analysis was performed on one aliquot. The other 3 specimen were stored for a) 24 h at room temperature (RT, 20 +/- 2 degrees C), at room temperature with agitation and c) at +4 degrees C. For flow cytometric analyses, samples were labeled with two CD34 markers (HPCA-2, Becton Dickinson Corp. [BD], USA; QBend-10, Immunotech Corp. [IT], Germany). After 24 h CD34+ signals had decreased by 25.4% (BD) and 27.0% (IT) in average, when samples were stored at room temperature in comparison to the results obtained directly after cytapheresis (p < 0.05). At RT in combination with agitation, there was an increase in signal rates compared to baseline values, probably due to binding of CD34 antibodies to myeloid or non-viable cells (+ 9.2% [BD] and 11.2% [IT]). At a storage temperature of +4 degrees C, CD34+ events did not decrease significantly (-0.7% [BD] and -0.2% [IT]). Our data demonstrate that FC results may be influenced by temperature, agitation and storage time.

[Elimination of hydroxyethyl starch after autologous retransfusion of cryopreserved erythrocytes]. / Elimination von Hydroxyethylstärke nach autologer Retransfusion von damit kryokonservierten Erythrozyten.

In the case of the biodegradable cryoprotectant hydroxyethyl starch (HES) no deglycerolization process is required prior to the transfusion of frozen red blood cells (RBC). In a first study the elimination of an HES 200,000/0.62 from the plasma of 6 dogs was investigated by means of a novel HPLC-GFC method. 16% of the blood volume were replaced by autologous HES protected frozen/thawed RBC. In a second study the HES concentration in the plasma of 7 healthy volunteers was determined following the substitution of 8% of the blood volume, but a washing step has been performed to reduce the concentration of the cryoprotectant (HES 200,000/0.5). In a third study, however, this step was omitted. The elimination of the HES followed always first order kinetics. In the case of the transfusions without postthaw washing in dogs and humans, the initial plasma concentrations amounted to 2.11 +/- 0.15 g/dl and 0.75 +/- 0.26 g/dl, respectively. The corresponding value for the washed preparations was less than 0.03 g/dl. Within 4-5 h the concentrations dropped to less than 50% of the initial values. The 9-hour value was less than 35% (dogs), the 20-hour value about 15% (humans) of the initial concentration. As HES is primarily eliminated via the kidneys, within this period the concentrations of HES in the urine dropped from 4.3 +/- 2.11 g/dl to less than 0.03 g/dl (humans, no washing step). In conclusion, the elimination of the accompanying cryoprotectant HES was no problem in the concentrations applied. A simple washing step with isotonic saline, however, effectively reduced the concentration of the extracellular cryoprotectant HES far below critical levels.

The effect of storage temperature on the stability of frozen erythrocytes.

A systematic study on the stability of frozen erythrocytes was performed. Washed and concentrated erythrocytes were mixed with an equal volume of cryoprotective solution containing 24% (w/w) hydroxyethyl starch (HES) and 60 mmol/liter NaCl according to an established protocol. Volumes of 250 microliters of this mixture were filled into polypropylene tubes and cooled to -196 degrees C with a rate of 293 degrees C/min by immersion in liquid nitrogen. The storage temperature was then varied from -10 to -75 degrees C and could be identified as the predominant factor influencing hemolysis kinetics. The effect of storage temperature on the frozen erythrocytes after thawing was evaluated by measuring the hemolysis in a dilute, isotonic NaCl solution (saline stability). A strong time dependence was found within the temperature range studied and could be described by an exponential kinetic law. A stability prediction was made for storage temperatures lower than those examined. Temperature ranges of qualitatively different hemolysis kinetics were identified and compared to devitrification behavior of intra-and extracellular solutions. The intracellular solution was simulated by a concentrated mixture of dried erythrocytes and water. The devitrification behavior was studied using DSC techniques. A rapidly frozen mixture was annealed at selected temperatures which fall into the range of storage temperatures for frozen erythrocytes. This paper tentatively interprets the devitrification data with respect to the means for cell damage during storage. The results are reviewed with respect to the design of a safe storage procedure.

[Characterization of 24-hour survival rate and duration of survival of hydroxyethyl starch cryopreserved erythrocytes after autologous transfusion in the dog]. / Charakterisierung der 24-Stunden-Uberlebensrate und Lebensdauer von mittels Hydroxyethylstärke kryokonservierten Erythrozyten nach autologer Transfusion im Hund.

BACKGROUND: Cryopreservation of erythrocytes using hydroxyethyl starch (HES) as cryoprotecting additive could result in a nearly unlimited storage stability of preserved red cells. In addition, it would allow its immediate use for transfusion. In order to assess the therapeutic efficacy of erythrocytes cryopreserved with HES, their 24-hour post-transfusion survival and long-term survival was evaluated. MATERIALS AND METHODS: The experiments were carried out with dog erythrocytes as an animal model for human erythrocytes. To each of 6 German shepherd dogs a 15-ml sample of erythrocyte suspension, labeled with 51Cr (25 microCi) after thawing, was autologously injected. Caused by hemolysis 29% of the formerly cryopreserved erythrocytes have not been labeled. To each of 6 control animals 15 ml of a suspension of freshly drawn and 51Cr-labeled erythrocytes was injected. The 51Cr radioactivity in later taken blood samples was a measure for the number of injected erythrocytes having remained in the circulation until the moment of blood withdrawal. The effect of cryopreservation was assessed by comparison of the test group with the control group. RESULTS: In both groups 30% of the applied cells left the circulation within 30 min. This was effected by pharmacological enlargement of the dogs' spleen and not by hemolysis of the erythrocytes. After the first 24 h all of the cryopreserved labeled erythrocytes had survived to the same amount (> 95%) as the labeled fresh red cells. Between 12 h and 20 days after injection, in both groups the 51Cr activity decreased exponentially by 4.8 and 4.5%/d. This difference was not significant. The area under the curve amounted to 1253 and 1257% d, respectively. CONCLUSIONS: There exists a subpopulation of red cells that is destroyed by freezing stress. As a result the freed stroma would be a serious transfusion risk. All erythrocytes having survived the cryopreservation procedure resemble the fresh erythrocytes with regard to the in-vivo survival; their therapeutic efficacy is not impaired. In the context of in-vitro results with human erythrocytes it can be expected that at the present developmental state of the cryopreservation procedure at least 93% of the human erythrocytes cryopreserved with HES have a normal 24-hour and long-term post-transfusion survival.

[Cryopreservation of erythrocytes using hydroxyethyl starch: in vivo results of an autologous retransfusion model in humans]. / Kryokonservierung von Erythrozyten mit Hydroxyethylstärke: In-vivo-Ergebnisse im autologen Retransfusionsmodell beim Menschen.

The cryopreservation of human red blood cells (RBC) can be greatly beneficial in certain situations such as for rare blood groups, problems due to multiple antibodies, and as an interim aid during temporary shortages. Additionally, cryopreserved erythrocytes may be useful in cases of civil or military disasters. Frozen/thawed autologous RBC are of particular interest as a supplement to liquid storage for elective operations (e.g. orthopedics, vascular and transplantation surgery) to extend the preoperative collection period, which is otherwise limited to 7 weeks. In this study using 7 healthy volunteers, 500 ml of whole blood was replaced by a suspension of cryopreserved autologous RBC [2 aliquots of 216 ml each, hematocrit (HCT) 43 +/- 2% (v/v), HES (hydroxyethyl starch) concentration 11.5% (w/w)]. No washing step was performed after thawing. Viability of the red cells after thawing in terms of saline stability reached 91.9 +/- 0.7% (n = 4). In all 7 cases the frozen/ thawed autologous RBC were tolerated very well. No adverse reactions could be detected. A slight posttransfusional leukocytosis as well as a moderate increase in LDH and bilirubin were observed, but these effects disappeared within 20 h. The concentrations of platelets, electrolytes, urea, protein and creatinine within their physiological ranges. The activities of the liver enzymes and the coagulation parameters investigated remained unchanged. Initially the level of free plasma hemoglobin increased by a factor of 2. Then it decreased within 20 h, accompanied by a restoration of haptoglobin. More than 85% of the HES was eliminated from the plasma within the 1st day.

[Cryopreservation of human erythrocytes with hydroxyethyl starch (HES)--Part 1: The procedure]. / Kryokonservierung von Human-erythrozyten mit Hydroxyethylstärke (HES)--Teil 1: Verfahrensbeschreibung.

Although the efficacy of hydroxyethyl starch (HES) as a cryoprotectant for human red blood cells (HRBC) was demonstrated in 1967, no clinical application has evolved so far. In contrast to glycerol, which has been widely used for this purpose, HES offers the advantage of being nontoxic if administered intravenously. Being also a plasma substitute, HES in combination with HRBC can normalize blood volume as well as oxygen transport in the case of extended blood loss. This may be of importance for autologous blood supply for elective surgery and for disaster treatment plans. For a volume of 40 ml, the optimal combination of important parameters [e.g. cooling rate 200-250 K/min, warming rate 400 K/min, hematocrit 40%, HES concentration 12% (w/w)] has led to a survival after thawing in terms of saline stability of 93 +/- 1% (n = 10). Additionally, the age prior to cryopreservation (0-3 days) had an influence on postthaw survival, but at least 90% survival can be obtained if the samples are washed 3-5 times before freezing.

[Cryopreservation of human erythrocytes with hydroxyethyl starch (HES)--Part 2: Analysis of survival]. / Kryokonservierung von Human-erythrozyten mit Hydroxyethylstärke (HES)--Teil 2: Vitalitätsanalytik.

Red blood cells (RBC) were obtained from 5 whole blood units by centrifugation and were purified using a simple washing procedure. Hematocrit and HES concentration in the 108-ml samples to be frozen were adjusted to 40% (v/v) and 12% (w/w), respectively. Cooling was performed by submerging into liquid nitrogen using containers to generate a flat sample geometry (3 mm thickness). After thawing in a shaking water bath, HES and free hemoglobin were removed in a simple washing step. To investigate the influence of the resuspension medium, the RBC were transferred into freshly drawn autologous plasma and into Locke's solution. Survival after thawing in terms of saline stability reached 86.3 +/- 2.3%. The cryopreservation procedure caused no major changes with regard to osmotic fragility, 2,3-DPG or intracellular Na+ and K+. ATP was reduced by 16%, but this had completely recovered after 3 h resuspension in autologous plasma. Some morphological changes present after thawing (e.g. stomatocytes, echinocytes) also recovered after 1.5 h. In conclusion, those RBC which survived the preservation process can be considered to be fully viable with regard to the parameters investigated.

[Cryopreservation of erythrocytes with hydroxyethyl starch. In vitro results leading to an autologous retransfusion model in the dog]. / Kryokonservierung von Erythrozyten mit Hydroxyethylstärke (HES). In-vitro-Ergebnisse auf dem Weg zum autologen Retransfusionsmodell beim Hund.

Although the effectiveness of hydroxyethyl starch (HES) as a cryoprotectant for human red blood cells (HRBC) is well known, no clinical application has evolved so far. In contrast to glycerol HES has the advantage of causing no hemolysis per se. This offers the opportunity of a one-step procedure without a time consuming postthaw washing procedure prior to transfusion. In this study the in vitro results obtained with red blood cells from 8 dogs (DRBC) are reported and compared to HRBC (n = 5). It turned out that DRBC had a similar 2,3-DPG and a lower ATP content. Postthaw survival in terms of saline stability differed markedly (67 +/- 6 and 86 +/- 2%, respectively). DRBC were more susceptible to hypotonic stress than HRBC. Nevertheless, after cryopreservation 91% (HRBC) and 92% (DRBC) of the original 2,3-DPG were found in the thawed RBC concentrates.