Supernatant reduction of stored gamma‐irradiated red blood cells minimizes potentially harmful substances present in transfusion aliquots for neonates

Abstract

BACKGROUND In neonate transfusion, the use of a dedicated red blood cell (RBC) unit decreases donor exposure. A separate safety measure involves gamma irradiation of the RBCs to abrogate the possibility of transfusion‐associated graft‐versus‐host disease. However, in combination, storage of gamma‐irradiated RBCs leads to accumulation of potentially harmful substances in the supernatant. STUDY DESIGN AND METHODS For this study, RBCs were pooled and split into three study arms. Centrifugation or gravity was used to pack RBCs of matched units thereby reducing the amount of supernatant that would be present in neonate transfusion aliquots; these were compared to matched control units. Supernatant measurements of potassium, hemoglobin (Hb), RBC microvesicle (RMV) content, and mannitol were made in aliquots prepared weekly up to 21 days after gamma irradiation. RBC morphology and osmotic fragility were also assessed to determine if supernatant reduction methods affected the storage lesion. RESULTS Potassium and mannitol were significantly decreased in transfusion aliquots prepared with either of the supernatant reduction methods. On Day 21, potassium levels from supernatant‐reduced aliquots were below those of Day 7 control aliquots. A decrease in free Hb was only detected on Day 21 in centrifuged aliquots. RMVs were significantly reduced in centrifuged aliquots and significantly increased in gravity‐settled aliquots. The only measurable effect on storage lesion was a small increase in osmotic fragility of the RBCs subjected to supernatant reduction. CONCLUSION Supernatant reduction by centrifugation effectively reduces potassium, mannitol, and RMVs in aliquots from gamma‐irradiated RBCs stored up to 21 days.

Contrasting effects of stored allogeneic red blood cells and their supernatants on permeability and inflammatory responses in human pulmonary endothelial cells

“…In agreement with earlier studies, we also found that RBC supernatants possess barrier-disruptive properties (38,46,50,52,56,67). Surprisingly, supernatants from fresh RBCs or old RBCs had same degree of deleterious effects on ECs with that of old RBCs, suggesting that these harmful substances are present in RBC from the beginning, opposing the existing theory that they accumulate during storage.…”

Centrifugation‐free washing: A novel approach for removing immunoglobulin A from stored red blood cells

“…This conjecture is supported by higher hemolysis and free Hb concentration in the centrifuged sample, and a slightly higher EI at high shear, which is related to the maximal extensibility of RBCs and therefore would increase most if the number of spherical cells is reduced (Table ). The difference in the effect of different types of washing on properties of stored RBCs is intriguing, and should warrant further careful investigation, because of the potential risks associated with transfusion of poorly‐preserved, fragile RBCs to susceptible patients …”

Effect of modern infusion pumps on RBC quality

“…Supernatant preparation and measurement of variables including free Hb (fHb), potassium ion and RBC-derived microvesicles (RMVs) levels were performed as previously reported. 15 Hemolysis % was calculated according to the following equation: hemolysis % = fHb  (100 À Hct)/Hb t . Lactate dehydrogenase (LDH) concentrations were measured using a colorimetric LDH assay kit (ab 102526, Abcam).…”