Osmotic hemolysis is a donor-specific feature of red blood cells under various storage conditions and genetic backgrounds.

BACKGROUND: Transfusion research has recently focused on the discovery of red blood cell (RBC) storage capacity biomarkers and the elucidation of donor variation effects. This shift of focus can further strengthen personalization of transfusion therapy, by revealing probable links between donor biology, RBC storage lesion profile, and posttransfusion performance. STUDY DESIGN AND METHODS: We performed a paired correlation analysis of osmotic fragility in freshly drawn RBCs and during cold storage in different preservative solutions at weekly intervals until unit's expiration date (n = 231), or following 24 h reconstitution in allogeneic plasma (n = 32) from healthy controls or transfusion-dependent beta-thalassemia patients. RESULTS: We observed exceptional correlation profiles (r > 0.700, p < 10-5 in most cases) of RBC osmotic fragility in the ensemble of samples, as well as in subgroups characterized by distinct genetic backgrounds (sex, beta-thalassemia traits, glucose-6-phosphate dehydrogenase deficiency) and storage strategies (additive solutions, whole blood, RBC concentrates). The mean corpuscular fragility (MCF) of fresh and stored RBCs at each storage time significantly correlated with the MCF of stored RBCs measured at all subsequent time points of the storage period (e.g., MCF values of storage day 21 correlated with those of storage days 28, 35 and 42). A similar correlation profile was also observed between the osmotic hemolysis of fresh/stored RBCs before and following in vitro reconstitution in plasma from healthy controls or beta-thalassemia patients. CONCLUSION: Our findings highlighted the potential of osmotic fragility to serve as a donor-signature on RBCs at every step of any individual transfusion chain (donor, blood product, and probably, recipient).

Red cell transfusion in paediatric patients with thalassaemia and sickle cell disease: Current status, challenges and perspectives.

Notwithstanding the high safety level of the currently available blood for transfusion and the decreasing frequency of transfusion-related complications, administration of labile blood products to paediatric patients still poses unique challenges and considerations. The incidence of thalassaemia and sickle cell disease in the paediatric population may be high enough under specific racial and geographical contexts. Red cell transfusion is the cornerstone of ß-thalassaemia treatment and one of the most effective ways to prevent or correct specific acute and chronic complications of sickle cell disease. However, this life-saving strategy comes with its own complications, such as additional iron overload, alloimmunization and haemolytic reactions, among others. In paediatrics, the dependency of the transfusion outcome upon disease and other recipient characteristics is more prominent compared with the adults, owing to differences in developmental maturity and physiology that render them more susceptible to common risks, exacerbate the host response to transfused cells, and modify the type or the clinical severity of the transfusion-related morbidity. The adverse branch of red cell transfusion is likely the overall effect of several factors acting synergistically to shape the clinical phenotype of this therapy, including inherent donor/blood unit variables, like antigenicity, red cell deformability and extracellular vesicles, as well as recipient variables, such as history of alloimmunization and inflammation level at time of transfusion. This review focuses on paediatric patients with ß-thalassaemia and sickle cell disease as a recipient group with distinct transfusion-related characteristics, and introduces new concepts for consideration, not adequately studied and elucidated so far.