Stability of lymphocytes and Epstein-Barr virus during red blood cell storage.

Background: The Epstein-Barr virus (EBV) establishes and maintains latent infection in B lymphocytes of the healthy adults. Lymphocytes remain viable during red blood cell (RBC) storage. The effect of RBC storage on the stability of EBV-infected B lymphocytes and EBV genome is not known.

Methods: Eight randomly selected non-leukoreduced AS-5 RBC units were stored for 42 days under standard blood bank refrigerated at 1-6 degrees C. Cell count and EBV genomes in CD19+ B lymphocytes were measured in fresh products and weekly for 6 weeks. Total white blood cells (CD45+), T lymphocyte (CD3+), and B lymphocyte (CD19+) were quantified by a single platform flow cytometric assay. EBV genomes were quantified by real-time polymerase chain reaction using DNA purified from CD19+ B cells.

Results: Viable white blood cell, T and B lymphocytes followed a biphasic decline curve during RBC storage consisting of a steep steady decline during the first 3 weeks followed by a plateau for the remainder of the storage. At the end of the RBC shelf-life, 19% of the original T and B cells remained viable. EBV genomes per 10(5) CD19+ B lymphocytes remained constant during RBC storage. However, the total EBV genomes in the RBC units decline by more than 80% of their original value at the end of RBC storage due to loss of viable B lymphocytes.

Conclusions: The results indicate that lymphocytes and EBV latently infected B cells can survive the normal storage conditions for RBC.