Inactivation of viral and prion pathogens by γ-irradiation under conditions that maintain the integrity of human albumin

Background and Objectives The administration of therapeutic plasma protein concentrates has been associated with the real risk of transmitting viral diseases and the theoretical risks of prion transmission. Our objective was to determine if gamma-irradiation can inactivate viral or prion infectivity without damaging a protein biotherapeutically. Materials and Methods Human albumin 25% solution, spiked with four model viruses (including porcine parvovirus) or with brain homogenate from scrapie-infected hamsters, was gamma-irradiated at constant low-dose rates and assayed for viral and prion infectivity or for albumin integrity. Results At a radiation dose of 50 kGy, viruses were inactivated by greater than or equal to 3.2 to greater than or equal to 6.4 log(10) and scrapie by an estimated 1.5 log(10), whereas albumin was only moderately aggregated and fragmented. Conclusions gamma-Irradiation can preferentially inactivate viral and prion pathogens without excessive damage to albumin structure.