Posttransfusion Survival Research Articles

Prolonged storage of red cells: the effect of pH, adenine and phosphate.

Prolonged storage of red blood cells (RBCs) at 4 degrees C results in decreased intracellular ATP levels with diminished posttransfusion survival. Meryman described a preservative medium, exceptional in its capacity to increase these intracellular levels during the first weeks of storage and later in maintaining adequate levels, for extended storage periods. We modified this medium, investigated its constituents, and found that its ATP-preserving effect was unrelated to its tonicity or to the presence of mannitol. Throughout storage, RBC potassium leakage and lactate production were moderate. No evidence of osmotic swelling was detected. In spite of high ATP levels, the cells became echinocytes, thus discounting a direct correlation between shape and metabolic status. The most striking finding in this study was that the prestorage pH of the blood unit (pH 7.0), has a crucial contribution in elevating nucleotide levels in a medium containing high levels of phosphate (18-40 mM) and adenine. We suggest that a combined effect of optimal pH, adenine, glucose and phosphate in the medium contributes to the ability of the RBCs to synthesize the necessary purine nucleotides by the 'salvage pathway'.

Half-strength citrate CPD combined with a new additive solution for improved storage of red blood cells suitable for clinical use.

Currently used systems for red blood cell (RBC) collection and storage for transfusion have the disadvantage that the RBC 2,3-bisphosphoglycerate (BPG) concentration is depleted within two weeks of storage, resulting in a left-shift of the oxygen dissociation curve and a temporarily impaired capacity to deliver oxygen. We have studied the effects on red cell metabolism, morphology and in vivo recovery of 49-day storage of RBC, with collection in half-strength citrate CPD (0.5CPD) and storage in an additive solution containing citrate, adenine, mannitol, phosphate and glucose (RAS2). Traditional CPD-SAGM was used for comparison. Component preparation was performed after an initial holding period of the whole blood at ambient temperature for 8 h. The BPG concentration in 0.5CPD-RAS2 RBC was 0.633 +/- 0.120 mol (mol Hb)-1 as compared to 0.454 +/- 0.138 mol (mol Hb)-1 in CPD-SAGM RBC which implied a decrease to 67 and 48% of normal concentration, respectively. The mean RBC BPG concentration was maintained at the initial level for 28 days in the new system but decreased to very low levels within 14 days in the controls. The total adenine nucleotides were well maintained in both systems, adenosine triphosphate slightly better in the new system. Hemolysis after 49 days was 0.35 +/- 0.21% in the new system and 0.72 +/- 0.25% in the controls (p < 0.001). The morphology was better maintained in the new system (p < 0.001). The 24-hour posttransfusion survival of 49-day stored RBC was 78.9 +/- 7.1%. The membrane leakage of sodium and potassium was not significantly different in the two systems.(ABSTRACT TRUNCATED AT 250 WORDS)

Half-Strength Citrate CPD Combined with a New Additive Solution for Improved Storage of Red Blood Cells Suitable for Clinical Use

Currently used systems for red blood cell (RBC) collection and storage for transfusion have the disadvantage that the RBC 2,3-bisphosphoglycerate (BPG) concentration is depleted within two weeks of storage, resulting in a left-shift of the oxygen dissociation curve and a temporarily impaired capacity to deliver oxygen. We have studied the effects on red cell metabolism, morphology and in vivo recovery of 49-day storage of RBC, with collection in half-strength citrate CPD (0.5CPD) and storage in an additive solution containing citrate, adenine, mannitol, phosphate and glucose (RAS2). Traditional CPD-SAGM was used for comparison. Component preparation was performed after an initial holding period of the whole blood at ambient temperature for 8h. The BPG concentration in 0.5CPD-RAS2 RBC was 0.633±0.120 mol (mol Hb)^-1 as compared to 0.454±0.138 mol (mol Hb)^-1 in CPD-SAGM RBC which implied a decrease to 67 and 48% of normal concentration, respectively. The mean RBC BPG concentration was maintained at the initial level for 28 days in the new system but decreased to very low levels within 14 days in the controls. The total adenine nucleotides were well maintained in both systems, adenosine triphosphate slightly better in the new system. Hemolysis after 49 days was 0.35±0.21% in the new system and 0.72±0.25% in the controls (p<0.001). The morphology was better maintained in the new system (p<0.001). The 24-hour posttransfusion survival of 49-day stored RBC was 78.9±7.1%. The membrane leakage of sodium and potassium was not significantly different in the two systems. The concentration of inorganic phosphate (Pi) in the extracellular fluid of 0.5 CPD-RAS2 RBC was initially 7.1±0.8 mmol l^-1. It decreased to approximately 5.5 mmol l^-1 during the first 2 weeks of storage and then slowly increased to 9.4±0.9 mmol l^-1 on day 49. Pi in the CPD-SAGM controls was low initially but rose to 6.2±0.4 mmol l^-1 at the end of storage. The new system offers clearcut advantages as compared to traditional systems and does not seem to raise any serious clinical objections against its use even in massive transfusions.

Evaluation of Posttransfusion Recovery and Survival of Transfused Red Cells

Increasing diversity of red cell preservation solutions has required more attention to the techniques of documenting the in vivo efficacy of stored red cell transfusion products. Use of double labels and survival studies will not only improve the precision of the measurement but, hopefully, will offer insight into some of the effects of the newer preservation systems. Further development of the low chloride hypotonic red cell storage solutions pioneered by Meryman may well result in red cell transfusion products that can be stored liquid in vitro for more than twice the normal in vivo lifespan. Verifying that such cells not only are recovered in the circulation but survive for the normal in vivo lifespan and function correctly will demand increasingly accurate techniques. The combination of assay precision and external imagability render radionuclide techniques the standard for verifying red cell efficacy despite the small disadvantage of the radiation absorbed dose.

Studies with biotinylated RBC: (1) use of flow cytometry to determine posttransfusion survival and (2) isolation using streptavidin conjugated magnetic beads.

Methods are reported for the quantitation and isolation of biotinylated red blood cells (B- RBC). The first method is for determination of posttransfusional survival of rabbit RBC by flow cytometry. The survival of B-RBC was measured using both fresh and paraformaldehyde-fixed cells with similar results. The posttransfusion survival of rabbit RBC measured in this way was normal. There was no indication of increased cell destruction due to antibodies directed against B-RBC and no evidence for loss of biotin from circulating cells. The second methodology is for the isolation of B-RBC from blood with streptavidin-coated magnetic beads. At least eighty percent of positive cells were recovered with very few false positives. Both methods may be helpful in the study of resealed erythrocytes.

Suitable survival and half‐life of red cells after frozen storage in excess of 10 years

To examine the appropriateness of the Food and Drug Administration's 10-year storage time for previously frozen red cells, 24-hour posttransfusion survival studies were performed, and the half-life of 3 units of autologous red cells that had been stored for 13.5, 14, and 17 years, respectively, was measured. The units had acceptable freeze-thaw-wash recovery (83.3-91.4%). When a 51Cr label was used for the previously frozen red cells and a simultaneous 52Cr label for freshly drawn autologous red cells was used as a comparison, it was seen that the previously frozen cells had normal 24-hour posttransfusion survival (75.1-88.4%) as well as normal half-life (23-33.7 days). These findings support further extension of the maximum allowable storage time for previously frozen red cells.

Identification of Alloimmunized Patients: Use of Radiolabeled Allogeneic Platelet Kinetic Measurements and Platelet Antibody Tests

In a group of stable, nonthrombocytopenic leukemia patients awaiting bone marrow transplantation, results of paired allogeneic radiolabeled platelet kinetic measurements were correlated with the results of several different platelet and lymphocytotoxic antibody tests to determine which parameters could be used to identify patients who were alloimmunized to platelets. Seven patients with acute leukemia who had been transfused during induction therapy were used as the test group, and, as a control group, five untransfused patients with chronic myelogenous leukemia were also studied. Concurrent fibrinogen survival measurements were performed in all patients to assess whether hemostatic factor consumption (ie, disseminated intravascular coagulation) was present. Allogeneic platelet survival measurements were reduced from normal in all 12 study patients. In 8 of 12 patients, fibrinogen and platelet survival measurements were comparably reduced, suggesting disease-related platelet consumption. In four heavily transfused patients with acute leukemia, allogeneic platelet survivals were markedly reduced to less than or equal to 2.1 days, compared with the 3.5- to 7.4-day platelet survival measurements found in the other eight patients. The disproportionately short platelet survivals compared with fibrinogen survival measurements in these four patients, combined with documented positive antibody tests to their donors' platelets in the three patients with evaluable tests, suggested that these patients had become alloimmunized to platelets because of their prior transfusions. There was substantial concordance between the two radiolabeled allogeneic donor platelet survival measurements performed in each of these patients, suggesting that host rather than donor factors have a major influence on transfusion outcome (r = .93, P less than .001). The platelet cross-match tests, using the radiolabeled protein Staph A assay combined with the IgG enzyme-linked immunosorbent assay test, had the best correlation with the posttransfusion recovery and survival of the donors' platelets.

Identification of alloimmunized patients: use of radiolabeled allogeneic platelet kinetic measurements and platelet antibody tests

In a group of stable, nonthrombocytopenic leukemia patients awaiting bone marrow transplantation, results of paired allogeneic radiolabeled platelet kinetic measurements were correlated with the results of several different platelet and lymphocytotoxic antibody tests to determine which parameters could be used to identify patients who were alloimmunized to platelets. Seven patients with acute leukemia who had been transfused during induction therapy were used as the test group, and, as a control group, five untransfused patients with chronic myelogenous leukemia were also studied. Concurrent fibrinogen survival measurements were performed in all patients to assess whether hemostatic factor consumption (ie, disseminated intravascular coagulation) was present. Allogeneic platelet survival measurements were reduced from normal in all 12 study patients. In 8 of 12 patients, fibrinogen and platelet survival measurements were comparably reduced, suggesting disease-related platelet consumption. In four heavily transfused patients with acute leukemia, allogeneic platelet survivals were markedly reduced to less than or equal to 2.1 days, compared with the 3.5- to 7.4-day platelet survival measurements found in the other eight patients. The disproportionately short platelet survivals compared with fibrinogen survival measurements in these four patients, combined with documented positive antibody tests to their donors' platelets in the three patients with evaluable tests, suggested that these patients had become alloimmunized to platelets because of their prior transfusions. There was substantial concordance between the two radiolabeled allogeneic donor platelet survival measurements performed in each of these patients, suggesting that host rather than donor factors have a major influence on transfusion outcome (r = .93, P less than .001). The platelet cross-match tests, using the radiolabeled protein Staph A assay combined with the IgG enzyme-linked immunosorbent assay test, had the best correlation with the posttransfusion recovery and survival of the donors' platelets.

Studies in Red Blood Cell Preservation: 4. Plasma Vesicle Hemoglobin Exceeds Free Hemoglobin

Studies were designed to find out how much of the plasma hemoglobin (Hb) in whole blood was in microvesicles and how much was free Hb after 21 days of storage in citrate-phosphate-dextrose anticoagulant and to determine the effect of the plasticizer, di-(2-ethylhexyl) phthalate (DEHP). The total plasma Hb in polyolefin (PO) containers without DEHP was much higher than in polyvinyl chloride (PVC) with the plasticizer (p = 0.004). Less than 30% of the Hb was in free solution in either type of container. The addition of 300 µg/ml of DEHP to the plasma in the PO containers resulted in marked reduction in the microvesiculation (p<0.01) but did not affect the level of free Hb. RBC hypotonic fragility and morphology scores were significantly improved. It is concluded that microvesiculation contributes more to plasma Hb concentration than free Hb during storage. Some hemolysis of red blood cells (RBC) is expected during blood bank storage. It has been shown that part of the hemoglobin (Hb) in the suspending medium is free and part is encapsulated in microvescicles shed by the RBC [1], The amount of hemolysis and microvesiculation that occurs has been noted to be less when blood is stored in polyvinyl chloride (PVC) containers in which di-(2-ethylhexyl)phthalate (DEHP) is used as the plasticizer [1]. The DEHP that leaches into the plasma has been shown to decrease hemolysis, microvesiculation, and the increase in osmotic fragility which RBC undergo during refrigerated storage [2-9]. The posttransfusion survival of RBC stored in DEHP-plasticized PVC has been found superior to RBC stored in PVC bags plasticized with tri-2-ethylhexyl-trimellitate (TEHTM) which is much less leachable. The protective effect of the DEHP is believed to be due to its insertion into the RBC membrane [6-9], The present studies were done to quantify how much of the ‘hemolysis’ that has been observed during the storage of RBC is dissolved Hb and how much is Hb encapsulated in microvesicles.

長期保存ＭＡＰ加濃厚赤血球の有効性についてＳｕｒｖｉｖａｌ ｓｔｕｄｙ

Plasma and buffy coat poor red cells suspended in MAP solution which contains mannitol, adenine, glucose, phosphate and citrate, were stored for 6 weeks at 4-6°C and survival studies were carried out in vivo.The 24- and 48-hours autologus post-transfusion survivals of 51Cr-labeled red cells were 81.8±4.3% and 77.5±3.8% after 6 weeks storage (n=12), respectively.This additive solution, MAP enabled red cells to store for up to 6 weeks and to provide the excellent red cell products.

Storage of saline‐adenine‐glucose‐mannitol‐suspended red cells in a new plastic container: polyvinylchloride plasticized with butyryl‐n‐ trihexyl‐citrate

Blood collection and component preparation have been performed in integrally connected multiple plastic containers made with a new plastic. This polyvinylchloride (PVC) container plasticized with butyryl-n-trihexyl-citrate (BTHC) is a new material for blood storage; it contains no di(2-ethylhexyl)phthalate (DEHP). After removal of plasma and buffy coat, the red cells were suspended in saline-adenine-glucose-mannitol (SAGM) medium. After 42-day refrigerator storage, the total adenine nucleotide concentration remained the same as the initial concentration in the red cells, whereas ATP levels had decreased to 61 percent of the initial value. The 2,3 DPG concentration was 62 percent of normal on Day 7 and 21 percent on Day 14. Glucose consumption, lactate production, potassium leakage from red cells, and pH levels were similar to those found after storage in DEHP-plasticized containers under the same conditions. After 42 days, hemolysis levels were 0.56 +/- 0.21 percent and 0.42 +/- 0.17 percent in two series of units mixed weekly and 0.70 +/- 0.27 percent in units stored unmixed. Although even higher levels of hemolysis were observed in the units stored unmixed and used for 24-hour posttransfusion survival, the autologous red cell recovery results were excellent (83.2 +/- 5.1%, n = 8). BTHC-plasticized PVC is found to be a suitable material for 42-day storage of red cells in SAGM solution.

Inhibition of the enzyme purine nucleoside phosphorylase (PNP) reduces refractoriness to transfused platelets in a dog model

To better define the role of T-cells in alloimmunization, we induced purine nucleoside phosphorylase (PNP) deficiency in a dog platelet transfusion model. Short-term administration of eight different drug schedules using several combinations of the PNP inhibitor 8-aminoguanosine and/or deoxyguanosine did not induce significant toxicity in four treated animals as demonstrated by blood chemistries, cell counts, and autologous platelet recovery and survival measurements. However, continuous long-term daily administration of these agents produced significant renal and/or hepatic toxicity leading to death in five of six animals. Modification of the drug schedule to early short-term administration of both deoxyguanosine and 8-aminoguanosine, followed by long-term intermittent doses of only 8-aminoguanosine, was not only well tolerated by all the animals but also resulted in significant immunosuppression. Overall, six of nine evaluable dogs (67%) treated with some combination of PNP inhibitors did not become refractory to eight weekly transfusions of platelets from a single random donor dog, P less than 0.005, compared to untreated controls, only 3/21 (14%) not immunized. Furthermore, in four evaluable recipients, discontinuation of the 8-aminoguanosine while continuing platelet transfusions from their original donors did not result in refractoriness. In addition, these four recipients were also unable to recognize platelets from two other random donors. This suggests that both specific and non-specific tolerance to foreign platelet antigens had been induced by PNP-inhibitor therapy. Other evidence for the efficacy of this immunosuppressive treatment was the almost normal post-transfusion recovery and survival of donor platelets, both during and after treatment. This suggests failure to form even low levels of platelet alloantibodies in the immunosuppressed recipients. In contrast, B-cell immunity to soluble antigens was intact as demonstrated by a normal antibody response to keyhole limpet haemocyanin (KLH) antigen.

Development of a combined storage medium for 7‐day storage of platelet concentrates and 42‐day storage of red cell concentrates

Studies were carried out to examine whether a single additive solution could support both platelet and red cell storage. An ionically balanced electrolyte solution fortified with citrate, glucose and bicarbonate was used. This solution has previously been shown to provide good platelet viability with storage for up to 7 d. Optimization studies demonstrated that with adenine added to this solution (CSM), it also allowed for satisfactory preservation of in vitro red cell parameters for up to 49 d of storage. Confirmatory paired in vivo post-transfusion studies were carried out in which platelets and red cells obtained from the same donor were processed and stored in CSM on one occasion, and in CPD-plasma (platelets) and AS-1 (red cells) on another occasion. Five paired studies were conducted with platelets stored for 5 d and red cells for 42 d; another five paired studies with platelets stored for 7 d and red cells for 49 d. Except for a slight decrease in platelet survival (P less than 0.05) with storage in CSM, there were no statistically significant differences in post-transfusion recoveries and survivals between test and control media, demonstrating that both platelets and red cells may be satisfactorily stored in a combined single additive solution.

The in vivo survival of human red cells with low oxygen affinity prepared by the osmotic pulse method of inositol hexaphosphate incorporation

The purpose of this study was to determine the posttransfusion survival of low-affinity red cells (RBCs) containing the hemoglobin modifier, inositol hexaphosphate (IHP). An osmotic pulse technique was used to incorporate IHP, a compound that normally does not cross the RBC membrane. Two groups of six volunteers were studied. RBCs were treated under conditions that resulted in a relatively large increase in mean corpuscular volume (delta MCV = 11.8 +/- 4.0, 1 SD) in Group I, but a relatively small increase (delta MCV = 5.5 +/- 1.9) in Group II. The groups had a similar decrease in mean corpuscular hemoglobin (delta MCH = -3.8 +/- 0.9 for Group I and -3.1 +/- 1.1 for Group II). The 24-hour posttransfusion RBC survival, measured with 3 mL of 51Cr-labeled autologous RBCs, correlated with the induced change in oxygen affinity, and larger shifts were associated with poorer survival. An acceptable 75-percent 24-hour posttransfusion survival was achieved for p50 increases up to approximately 15 torr. Cells that survived 24 hours appeared to have a normal lifespan. This study is the first demonstration of adequate survival for human RBCs with a potentially long-lasting decrease in oxygen affinity.

In vitro and in vivo evaluation of platelet concentrates after cotton wool filtration.

Removal of leukocytes from platelet concentrates (PC) may decrease the incidence of alloimmunization to HLA antigens on white cells and prevent or delay refractoriness. Cotton wool filtration, which effectively removes leukocytes from PC with minimal platelet loss, may cause platelet or complement activation. In this study, the effect of cotton wool filtration (Imugard IG-500) on platelet activation, in vitro function, posttransfusion survival, and complement activation was investigated. Five paired autologous in vivo percent recovery and survival studies were performed with fresh (6-8h) PC or with 5-day-stored PC prepared from CPD-anticoagulated blood and stored in PL-732(TM) containers using standard methods. In the paired design, PC from the same donor were filtered on one occasion, and not filtered on another, prior to labeling with indium-III-oxine and reinfusion. Percent recovery and survival were then determined by the standardized method. Filtration had no statistically significant effect on percent recovery on PC stored for 6-8h or for 5 days. There was, however, a slight decrease in survival hours of the filtered PC which was statistically significant at 6-8h (203 +/- 14 vs. 179 +/- 18h; p less than 0.05) but not at 5 days (166 +/- 28 vs. 132 +/- 27h; p greater than 0.05). Samples taken before and after filtration of single units (fresh and 5-day) and pooled units (3-day) for measurement of release of granular content (beta-thromboglobulin), lysis (LDH), and in vitro viability - ATP, extent of shape change with ADP, and hypotonic shock response (3-day only)-demonstrated no effect of filtration on these parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

The safety and therapeutic effectiveness of human red cells stored at -80 degrees C for as long as 21 years.

Human red cells frozen by various methods have been stored in the frozen state at -80 degrees C for as long as 21 years. This report discusses: red cells frozen with 42 percent weight per volume (wt/vol) glycerol in an ionic medium in a polyvinylchloride (PVC) plastic bag using the Cohn method; red cells frozen with 45 percent wt/vol glycerol in a low ionic medium in a PVC plastic bag using the Huggins method; red cells frozen with 40 percent wt/vol glycerol in an ionic medium in a polyolefin plastic bag using the Meryman-Hornblower method; and red cells frozen with 40 percent wt/vol glycerol in an ionic medium in a standard 600-ml or an elongated 800-ml PVC plastic primary collection bag with an adapter port using the Naval Blood Research Laboratory (NBRL) method. After frozen storage for as long as 21 years by the four methods described above, the thawed red cells were deglycerolized with 50 to 150 ml of 12 percent sodium chloride and 1.5 to 2.0 l of sodium chloride-glucose or sodium chloride-glucose-phosphate solution. After washing and storage at 4 degrees C for 24 hour, the red cells had a mean freeze-thaw-wash recovery value of 90 percent, a mean 24-hour posttransfusion survival value of 85 percent, a mean index of therapeutic effectiveness of 75 percent, normal or slightly impaired oxygen transport function, and minimal hemolysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Posttransfusion survival of red cells frozen for 8 weeks after 42-day liquid storage in AS-3.

Current standards recommend that red cells (RBCs) should be frozen within 6 days of donation. There are situations, however, in which it is desirable to freeze RBCs that are older than 6 days, such as for the salvage of rare or autologous units. To determine the therapeutic efficacy of RBCs frozen after prolonged liquid storage, standard units were drawn from nine normal donors and stored at 4 degrees C for 42 days in a nutrient-additive solution, AS-3. 51CrRBC survival assays were performed (24-hour survival: 78.2 +/- 12.4%; n = 8) and the units were frozen at -80 degrees C in glycerol for 8 weeks. After deglycerolization, the mean RBC recovery was 81.0 +/- 4.1 percent and the mean 24-hour 51Cr survival was 78.0 +/- 9.1 percent. The index of therapeutic effectiveness (ITE) was determined by multiplying the postdeglycerolization 24-hour 51Cr survival by the mean RBC recovery (63.3 +/- 9.2). ITE values greater than 60 percent (75% 51Cr survival x 80% RBC recovery) were considered acceptable. Mean adenosine triphosphate levels declined from an initial 3.81 +/- 0.56 micromol per g of hemoglobin to 2.33 +/- 0.55 micromol per g after frozen storage. These findings show that an acceptable percentage of RBCs survives frozen storage after maximum liquid storage (mean ITE greater than 60%). If necessary, RBCs stored in AS-3 can be frozen at any time before 42 days.

The bottom and top system: a new technique for blood component preparation and storage.

A new, automated technique for the preparation of blood components is described. A system of 3 or 4 integrally connected plastic containers (Optipac) is handled by a new type of extractor (Optipress). The container in which the blood is collected has an outlet at the top and another at the bottom. After normal centrifugation to obtain separation of the blood components, these are squeezed out from the top and bottom simultaneously under control of a photocell. The primary separation step results in three components: a leukocyte-poor red-cell suspension in SAGM medium, CPD plasma, and a buffy-coat preparation. The system has been tested in two laboratories (lab A and lab B). A 'heavy-spin' centrifugation to obtain a maximum yield of cell-poor plasma gave the best removal of leukocytes from the red cells; the remaining leukocyte content was 0.46 +/- 0.25 (lab A) and 0.5 +/- 0.4 (lab B) x 10(9)/red-cell unit. Platelet concentrates can be prepared either the normal way via platelet-rich plasma or from buffy coat. Red-cell 24-hour autologous posttransfusion survival using labeling with 51Cr was 87.5 +/- 4.1% (lab A) after 35 days, and 84.2 +/- 4.2% (lab A) and 77.5 +/- 1.5% (lab B) after 42 days. Red-cell morphology and fluidity compared favorably to previous studies using the same additive solution in traditional plastic-bag systems. The total adenine nucleotide concentration was maintained normal for 42 days.(ABSTRACT TRUNCATED AT 250 WORDS)

The 24-hour posttransfusion survival and lifespan of autologous baboon red cells treated with inositol hexaphosphate-polyethylene glycol or inositol hexaphosphate-adenosine triphosphate-polyethylene glycol to decrease oxygen affinity.

Baboon red cells were treated to reduce oxygen affinity by an osmotic-pulse procedure using dimethyl-sulfoxide. Inositol hexaphosphate (IHP) alone or IHP and adenosine triphosphate (ATP) were incorporated into the red cells in the presence of polyethylene glycol (PEG). The procedure produced variable increases in the red cell P50 value, i.e., the partial pressure of oxygen at which 50% of the hemoglobin was saturated. The effect of treatment of autologous baboon red cells on the 24-hour posttransfusion survival value and lifespan T50 value was measured using a double-label procedure. The data demonstrate that the increase in the P50 value of treated red cells was negatively correlated with the 24-hour posttransfusion survival value; the higher the P50 value, the poorer the 24-hour posttransfusion survival value. The 24-hour posttransfusion survival value for nontreated baboon red cells was 90% and the T50 value was 14 days. The IHP-ATP-PEG-treated red cells had significantly higher red cell ATP levels than did IHP-PEG-treated red cells. The 24-hour posttransfusion survival value was 68% for the IHP-ATP-PEG treated red cells and 52% for the IHP-PEG-treated red cells when the increase in P50 ranged from 10 to 20 mm Hg; the lifespan T50 value for both the IHP-ATP-PEG-treated red cells and the IHP-PEG-treated red cells was 15 days. Osmotic pulse treatment produced significant red cell injury manifested by the 24-hour posttransfusion survival value. However, modification of the RBC with IHP-PEG or IHP-ATP-PEG to decrease hemoglobin affinity for oxygen did not affect their lifespan.

The Effect of the Plasticizer Di-2-Ethylhexyl Phthalate on the Survival of Stored RBCs

Recent in vitro studies have shown that di-2-ethylhexyl-phthalate (DEHP) inhibits the deterioration of RBCs during refrigerated storage in containers that use this compound as a plasticizer. The experiments described in this report were designed to assess whether this in vitro protective effect of DEHP would result in a prolonged in vivo survival of RBCs infused into normal human recipients. Whole blood collected from ten normal donors was stored for 35 days in citrate-phosphate-dextrose-adenine (CPDA-1) anticoagulant contained in polyvinylchloride (PVC) bags plasticized with DEHP or a trimellitate compound that is known to have low leachability. Aliquots of RBCs from each container were then labeled with chromium-51 and were reinfused into the original donors. For blood stored in DEHP-plasticized PVC bags, 24% more red cells survived in vivo 24 hours after reinfusion than was observed when the blood had been stored in trimellitate-plasticized bags (P less than .001). Whole blood stored in glass bottles showed a similar improvement in in vivo survival when DEHP was added in weekly increments to mimic the accumulation of this plasticizer seen during storage in plastic containers. Survival of packed red cells stored in the presence of DEHP increased by 14% compared with storage in trimellitate-plasticized bags (P less than .05). In agreement with previous studies, hemolysis and microvesicle formation were also reduced in the presence of DEHP. These results suggest that proposed new storage systems lacking DEHP should be carefully evaluated to determine whether adequate post-transfusion survival of RBCs may be achieved.