Older Blood Used in Transfusions May Be Harmful to Adult Sickle Cell Patients, Review Finds

In an analysis of adults with sickle cell disease, researchers found evidence that transfusions with stored units of older blood were associated with higher rates of hospital admission due to infections.

The study, “Older red cell units are associated with an increased incidence of infection in chronically transfused adults with sickle cell disease,” was published in the journal Transfusion and Apheresis Science.

Current therapy for patients with sickle cell disease relies on red blood cell transfusions. However, there are few guidelines regarding the optimal red cell unit to be delivered to these patients.

An important factor that is currently not addressed in the practice of blood cell transfusions in sickle cell disease is the storage age of the red cell units kept in blood banks.

Refrigeration, although in controlled conditions, impacts the biochemical characteristics of red blood cells, a condition known as the storage lesion. These alterations include, for example, the release of potentially harmful byproducts of broken-down red cells, such as reactive oxygen species.

How red cell storage lesion affects adult patients with sickle cell disease remained largely unaddressed, however. Researchers from the Medical College of Wisconsin in Milwaukee and the Medical Sciences Institute at the BloodCenter of Wisconsin performed a retrospective analysis on the age of stored red cell units given to adult patients. They evaluated how storage age impacted patients’ clinical outcomes — particularly if storage age was associated with an increase in adverse outcomes.

They analyzed data from 28 adults with sickle cell disease who were managed with preventive simple transfusion regimens. These patients received a total of 627 units through simple transfusion over 281 outpatient encounters. The average age of the blood transfusion units was 22 days, but the age range varied from two to 42 days.

“We found a statistically significant association between emergency department and hospital admissions for infection and receipt of older units in the prior transfusion encounter,” the researchers wrote.

These results, although preliminary, carry an important message for the management of patients with sickle cell disease.

“Since few hospitals have protocols to provide younger units to adults with SCD, older units could put an already vulnerable person at higher risk of infection,” the researchers stated.