Liver and Bile
J Hepatol. 2022;76(1):46–52
Risk of transfusion-transmitted hepatitis E virus infection from pool-tested platelets and plasma
Background and aims: Immunocompromised patients are at risk of chronic hepatitis E which can be acquired by blood transfusions. Currently, screening of blood donors (BDs) for HEV RNA with a limit of detection (LOD) of 2000 IU/ml is required in Germany. However, this may result in up to 440,000 IU of HEV RNA in blood products depending on their plasma volume. The authors studied the residual risk of transfusion-transmitted (tt) HEV infection when an LOD of 2000 IU/ml is applied.
Methods: Highly sensitive individual donor testing for HEV RNA on the Grifols Procleix Panther system (LOD 7.89 IU/ml) was performed. HEV loads were quantified by real-time PCR.
Results: Of 16,236 donors, 31 (0.19%) were HEV RNA-positive. Three BDs had viral loads between 710 and 2000 IU/ml, which pose a significant risk of tt hepatitis E with any type of blood product. Eight BDs had viral loads of > 32 to 710 IU/ml, which pose a risk of tt hepatitis E with platelet or plasma transfusions because of their higher plasma volume compared to red blood cell concentrates. Eight of these 11 potentially infectious BDs were seronegative for HEV, indicating a recent infection. Only 8 of 31 donors had viral loads > 2000 IU/ml that would also have been detected by the required screening procedure and 12 had very low HEV loads (< 32 IU/ml).
Conclusions: Screening of blood donors with a limit of detection (LOD) of 2000 IU/ml reduced the risk of transfusion-transmitted HEV infection by about 73% for red blood cell concentrates but by just 42% for platelet and fresh frozen plasma transfusions. Single donor screening (LOD < 32 IU/ml) should lead to an almost 100% risk reduction.