Effect of rejuvenation and frozen storage on 42-day-old AS-1 RBCs.

BACKGROUND: The FDA has approved a 42-day storage period for RBCs stored in ADSOL (AS-1). This study was undertaken to provide data for the FDA about the feasibility of salvaging AS-1 RBCs at the end of their storage period by rejuvenation and freezing. STUDY DESIGN AND METHOD: The investigation, consisting of a study (n = 10) and control (n = 6) arm, was carried out in two centers. In both centers, eight healthy volunteers donated a unit (450 mL) of whole blood. The RBC concentrates were stored at 4 degrees C in AS-1 for 42 days. The study units were rejuvenated, whereas the control units were not. All units were stored frozen at -80 degrees C, then deglycerolized and kept for an additional 24 hours at 4 degrees C. RESULTS: After the 42-day storage period, ATP had declined to 62 percent of the original value, 2,3 DPG was zero, and MCV was significantly larger than that of fresh RBCS: Following rejuvenation and deglycerolization, the mean ATP level was 141 percent, the mean 2,3 DPG level was 109 percent, and the MCV was normal. The freeze-thaw-wash recovery of the rejuvenated and nonrejuvenated RBCs was similar, 88.4 and 84.0 percent, respectively. There was no difference in hypoxanthine, inosine, and uric acid levels in the rejuvenated and nonrejuvenated units, which indicated that the chemicals in the rejuvenation solution and their by-products had been removed during processing. In both centers, the mean 24-hour survival of rejuvenated, deglycerolized RBCs exceeded 75 percent, whereas that of nonrejuvenated RBCs did not. The long-term survival rates of viable study and control RBCs were similar. CONCLUSION: Forty-two-day-old AS-1 RBCs that have been rejuvenated and then frozen have more than 75 percent viability and normal oxygen delivery function. Rejuvenation of RBCs does not introduce additional safety hazards to blood transfusion.

Storage of platelets in earth orbit. Effect of gravity and the formulation of plastic storage containers on platelet IgG and C3.

We investigated the effects of gravitational force and three different plastic formulations of the storage bags on the quality of stored platelets by measuring the changes in platelet-associated immunoglobulin G (IgG) and two antigenic markers of the third component of human complement (C3), C3d and C3c. Pooled platelets were stored in parallel at microgravity (MG) and on the ground (1 g) using three different plastic polymers: (1) polyvinylchloride (PVC) plasticized with di-2-ethylhexyl phthalate (DEHP); (2) PVC plasticized with trioctyl trimellitate (TOTM), and (3) unplasticized polyolefin (PO). The IgG and C3 were quantified by an automated antiglobulin consumption test in freeze/thaw disrupted platelets (total IgG or C3). The baseline values for platelet associated IgG and C3, measured after 2.5 days of storage at 1 g just prior to the launch, fell within the normal range. Following an additional 6.5 day storage, platelets stored at MG had accumulated significantly less C3d than those stored at 1 g, suggesting that MG storage was beneficial. Specific plastic formulations also exerted a significant effect on the accumulation of these immunoproteins, the effect being particularly pronounced at MG. The smallest increases of IgG and C3 were seen in platelets stored in TOTM and the largest in those stored in DEHP. It is possible that further studies at MG would permit a clear characterization of the effects of other independent storage variables.

An autoanalyzer test for the quantitation of platelet-associated IgG.

A new quantitative antiglobulin consumption (QAC) test for the measurement of platelet-associated IgG is described. In this test washed platelets are incubated with anti-IgG at a final dilution of 1:2 million. The unneutralized fraction of anti-IgG remaining in solution is then measured with an Autoanalyzer and soluble IgG is used for calibration. The dose-response curves depicting the percent neutralization of anti-IgG by platelets and by soluble IgG were compared in detail and found to be nearly identical, indicating that platelet-associated IgG can be accurately quantitated by this method. The mean IgG values were 2,287 molecules/platelet for normal adults and 38,112 molecules/platelet for ITP patients. The Autoanalyzer QAC test is a sensitive and reproducible assay for the quantitation of platelet-associated IgG.

Studies on low-dose hydroxyethyl starch leukapheresis. Rate of elimination of HES in vivo and function of the harvested granulocytes in vitro.

We studied the rate of in vivo elimination of hydroxyethyl starch (HES) given during low dose HES leukapheresis in 9 donors and the effect of this procedure on the in vitro function of granulocytes in 3 donors. HES was eliminated more rapidly than has been previously reported for standard leukapheresis. Serum HES declined to one-half of peak concentration between 1 and 2 days and to one-tenth of peak in 23 days. No HES could be detected in serum 90 days after leukapheresis. The function of the harvested granulocytes was compared to that of granulocytes collected just prior to the procedure by measuring superoxide generation, ingestion and cell motility. There was no significant difference in the function of granulocytes harvested by low dose HES leukapheresis compared to those collected by venipuncture before the procedure.