Gamma-irradiation of deglycerolized red cells does not significantly affect in vitro quality.

BACKGROUND AND OBJECTIVES: Red cells frozen with glycerol may require gamma-irradiation after thawing and deglycerolization for transfusion to at-risk patients. Both freezing and irradiation are known to cause red cell damage. However, the effect of irradiation on the quality of deglycerolized red cells and the optimal shelf life of such a component is currently unknown. MATERIALS AND METHODS: Red cells (<7 days) were pooled, split and glycerolized using an ACP-215 automated cell washer (n = 12 pairs) and frozen at -80°C. Red cells were thawed, deglycerolized and resuspended in SAG-M. One of each pair was gamma-irradiated, while the other served as a control. Products were stored at 2-6°C and sampled for in vitro testing immediately after irradiation, and at 24 and 48 h postirradiation. RESULTS: Irradiation of deglycerolized red cells led to a >1·5-fold increase in extracellular potassium, compared to control units at 24 and 48 h postirradiation. Other parameters, including haemolysis, were not significantly affected by irradiation postdeglycerolization. CONCLUSION: Deglycerolized, irradiated red cells had increased supernatant potassium, but remained of acceptable quality for 24 h postirradiation.

Understanding the effects of gamma-irradiation on potassium levels in red cell concentrates stored in SAG-M for neonatal red cell transfusion.

BACKGROUND AND OBJECTIVES: Red cell transfusions, to paediatric patients, are often gamma-irradiated to prevent transfusion-associated graft-versus-host disease. This study measured changes in potassium and other in vitro parameters immediately following gamma-irradiation of paediatric and full-size red cell concentrates (RCCs). MATERIALS AND METHODS: The effects of irradiation on potassium release in RCCs stored in SAG-M were investigated under three scenarios. In the first scenario, RCC < 5 days was split into paediatric packs, gamma-irradiated and tested for potassium and haemolysis at 0, 2, 4, 6, 24 and 48 h. In the second scenario, full-size RCCs < 5 days postcollection were gamma-irradiated and tested as for the paediatric packs. Thirdly, RCCs < 14 days postcollection were gamma-irradiated and assessed at 6 and 24 h and 7 and 14 days. Each group contained paired controls that were not gamma-irradiated. RESULTS: In all situations, gamma-irradiation resulted in a twofold increase in potassium concentrations after 24 h of storage, compared to matched unirradiated controls. This difference was detectable as early as 2 h postirradiation. Few differences were observed between control and irradiated RCCs in other key parameters, including ATP, 2,3-DPG, haemoglobin, pH, glucose and lactate concentration. CONCLUSION: Gamma-irradiation of RCCs significantly increased extracellular potassium. Irradiation of fresher RCCs results in lower potassium concentrations, which is less likely to lead to hyperkalaemia upon transfusion.

Evaluation of the quality of blood components prepared using the Reveos automated blood processing system.

BACKGROUND AND OBJECTIVE: The Reveos automated blood processing system has been developed to combine primary and secondary processing of whole-blood units, resulting in a plasma unit, a red-blood-cell concentrate and an interim platelet unit per input. The aim of this study was to determine product specifications and in vitro quality of components produced by the Reveos system. MATERIALS AND METHODS: Whole blood was processed using the Reveos system and compared with historical Reference units produced using semi-automated methods. Reveos red cells were leucoreduced and stored in SAGM at 4°C. Reveos plasma was frozen at -30°C and factor activity was assessed after thawing. Reference red cell, plasma and buffy coats were produced by top and bottom processing. Leucoreduced Reveos and Reference platelet concentrates were prepared by pooling four interim platelet units or four buffy coats, respectively, with SSP+. RESULTS: Processing with the Reveos system was faster (76 min) than semi-automated separation (92 min). The red cell and platelet yields were higher in the units prepared by the Reveos system. The Reference and Reveos red cell and plasma units had very similar in vitro quality parameters. The platelet concentrates were also similar in many in vitro parameters, including pH, glucose and lactate metabolism, hypotonic shock response and phosphatidylserine expression, although platelet activation markers (CD62P and cytokine levels) were higher in the Reveos units. CONCLUSION: The Reveos system can improve blood component efficiencies through reductions in processing time, whilst maintaining similar component quality.

The effect of pathogen reduction technology (Mirasol) on platelet quality when treated in additive solution with low plasma carryover.

BACKGROUND AND OBJECTIVES: Pathogen reduction technologies (PRT) for platelets are now compatible with both plasma and platelet additive solutions (PAS). The aim of this study was to examine the effect of PRT on the platelet storage lesion, in the presence of PAS with low plasma carryover. MATERIALS AND METHODS: PRT-treated (Mirasol) and untreated buffy coat-derived platelet concentrates prepared in 28% plasma/PAS-IIIM were evaluated using in vitro cell quality parameters on days 1, 2, 5, and 7 post-collection. RESULTS: At day 5, there were no significant differences between control and PRT treated platelets for swirl, viability, pO(2) , pCO(2) , mean platelet volume and adenosine diphosphate-induced aggregation. PRT treatment did not affect the functional integrity of the mitochondria. However, PRT resulted in a decrease in pH and enhancement of platelet glycolysis and activation, evidenced by increased glucose consumption and lactate production rates, increased expression of CD62P, CD63, annexin V staining and increased secretion of cytokines (P < 0.05). Hypotonic shock response and aggregation in response to collagen were also significantly reduced in PRT treated platelets (P < 0.05). CONCLUSION: Despite the observed differences in platelet metabolism and activation observed following PRT treatment in PAS and low plasma carryover, the results suggest that treatment and storage of platelets in PAS is no more detrimental to platelets than treatment and storage in plasma.

Cryopreservation of buffy-coat-derived platelet concentrates in dimethyl sulfoxide and platelet additive solution.

Platelets prepared in plasma can be frozen in 6% dimethyl sulfoxide (Me(2)SO) and stored for extended periods at -80°C. The aim of this study was to reduce the plasma present in the cryopreserved product, by substituting plasma with platelet additive solution (PAS; SSP+), whilst maintaining in vitro platelet quality. Buffy coat-derived pooled leukoreduced platelet concentrates were frozen in a mixture of SSP+, plasma and 6% Me(2)SO. The platelets were concentrated, to avoid post-thaw washing, and frozen at -80°C. The cryopreserved platelet units (n=9) were rapidly thawed at 37°C, reconstituted in 50% SSP+/plasma and stored at 22°C. Platelet recovery and quality were examined 1 and 24h post-thaw and compared to the pre-freeze samples. Upon thawing, platelet recovery ranged from 60% to 80%. However, there were differences between frozen and liquid-stored platelets, including a reduction in aggregation in response to ADP and collagen; increased CD62P expression; decreased viability; increased apoptosis and some loss of mitochondrial membrane integrity. Some recovery of these parameters was detected at 24h post-thaw, indicating an extended shelf-life may be possible. The data suggests that freezing platelets in 6% Me(2)SO and additive solution produces acceptable in vitro platelet quality.

Dieldrin reduces male production and sex ratio in Daphnia galeata mendotae.

We used the sex ratio of neonate Daphnia, as well as the more standard endpoints of adult survivorship and fecundity and neonatal morphology, as an assay for detecting the effects of the insecticides endosulfan and dieldrin. Dieldrin caused a decrease in sex ratio (number of males/number of males plus females); we observed no endosulfan effect. We estimated (by extrapolation) that the sex ratio was reduced by dieldrin from concentrations of about 30 ppb and higher, based on a linear decrease in sex ratio with log dieldrin concentrations from 50 to 600 ppb. Neither insecticide significantly affected adult survival or clutch size. Because sex ratio changed but total neonate production did not change, the data suggest that the effect of dieldrin was on the sex-determining system during embryogenesis. Neither insecticide caused morphological abnormalities. Mixtures of the two pesticides produced only additive effects.