Reexamination of the chromium‐51–labeled posttransfusion red blood cell recovery method

Abstract

BACKGROUND: The chromium-51-labeled posttransfusion recovery (PTR) study has been the goldstandard test for assessing red blood cell (RBC) quality. Despite guiding RBC storage development for decades, it has several potential sources for error. METHODS: Four healthy adult volunteers each donatedan autologous, leukoreduced RBC unit, aliquots were radiolabeled with technetium-99m after 1 and 6 weeks of storage, and then infused. Subjects were imaged by single-photon-emission computed tomography immediately and 4 hours after infusion. Additionally, from subjects described in a previously published study, adenosine triphosphate levels in transfusates infused into 52 healthy volunteers randomized to a single autologous, leukoreduced, RBC transfusion after 1, 2, 3, 4, 5, or 6 weeks of storage were correlated with PTR and laboratory parameters of hemolysis.RESULTS: Evidence from one subject imaged after infusion of technetium-99m-labeled RBCs suggests that, in some individuals, RBCs may be temporarily sequestered in the liver and spleen immediately following transfusion and then subsequently released back into circulation; this could be one source of error leading to PTR results that may not accurately predict the true quantity of RBCs cleared by intra-and/or extravascular hemolysis. Indeed, adenosine triphosphate levels in the transfusates correlated more robustly with measures of extravascular hemolysis in vivo (e.g., serum iron, indirect bilirubin, non-transferrin-bound iron) than with PTR results or measures of intravascular hemolysis (e.g., plasma free hemoglobin).CONCLUSIONS: Sources of measurement error are inherent in the chromium-51 PTR method. Transfusion of an entire unlabeled RBC unit, followed by quantifying extravascular hemolysis markers, may more accurately measure true posttransfusion RBC recovery. T he chromium-51-labeled posttransfusion recovery (PTR) method is currently the gold-standard test for assessing the quality of stored red blood cells (RBCs) for transfusion. 1 As per the US Food and ABBREVIATIONS: AUC = area under the curve; FDA = US Food and Drug Administration; PTR = posttransfusion recovery; SPECT = single-photon-emission computed tomography; VOIs = volumes of interest. From the

Ferroportin inhibition attenuates plasma iron, oxidant stress, and renal injury following red blood cell transfusion in guinea pigs

“…We speculated that this observation resulted from slower clearance and prolonged intravascular retention of these cells. This observation is consistent with a small clinical study that evaluated posttransfusion recovery following 1 unit of 6‐week stored and technetium‐99m–labeled autologous RBCs, showing that, in some subjects, transfused RBCs were cleared gradually and even sequestered temporarily and then released back into circulation . Like the current observations in guinea pigs and those made in humans, it is reasonable to suspect longer circulation of storage‐damaged cells with larger RBC administration volumes.…”

Immunodeficient mice are better for modeling the transfusion of human blood components than wild-type mice

“…The rebound effect points to a sequestration of the human cells followed by their release. Human blood cells may temporarily adhere to the vasculature or be sequestered in tissues as a result of xenotransfusion, as was recently shown to occur with autologous transfusion in humans [ 25 ]. Disseminated intravascular coagulation, as a result of interspecies incompatibilities in coagulation factors, may also play a role in the rebound effect [ 26 ].…”

Donor glucose-6-phosphate dehydrogenase deficiency decreases blood quality for transfusion

“…Following screening and confirming G6PD activity, 10 G6PD-deficient and 30 G6PD-normal males donated 1 unit of whole blood at the New York Blood Center (New York, New er, respectively. The 24-hour PTR was then calculated using all timed blood draws for estimating the 51-chromium per gram hemoglobin circulating at time zero (70). Statistics.…”