Hepatitis E viral loads in plasma pools for fractionation

Area of Science:

• Virology
• Public Health
• Biotechnology

Background:

• Hepatitis E virus (HEV) can be present in blood donors, leading to detectable viral RNA in plasma pools for medicinal product manufacturing.
• Geographical prevalence of HEV in blood donors varies significantly based on local epidemiology.

Purpose of the Study:

• To investigate the presence and genotypes of HEV in manufacturing plasma pools from different global regions.
• To assess the implications of HEV detection for the safety of plasma-derived medicinal products.

Main Methods:

• Testing of 484 manufacturing plasma pools from North America, Europe, the Middle East, and Asia for HEV RNA using transcription-mediated amplification.
• Confirmatory analysis through real-time reverse transcription polymerase chain reaction and sequencing of detected HEV strains.

Main Results:

• HEV RNA was detected in plasma pools from Asia, North America, and Europe, but not in the Middle East.
• Asian pools exhibited the highest frequency of HEV RNA and viral loads, with strains clustering with Genotype 4.
• North American and European pools contained HEV Genotype 3, while Middle Eastern pools showed no evidence of HEV.

Conclusions:

• HEV is detectable in plasma manufacturing pools across multiple continents, necessitating risk assessment for plasma-derived medicinal products.
• Detected viral loads were low, consistent with large pool sizes and moderate individual donation viremia.
• Genotyping confirmed the presence of regionally circulating HEV strains, with the absence in Middle Eastern pools linked to low regional HEV prevalence.