The use of riboflavin for the inactivation of pathogens in blood products.
In recent years, the desire to develop methods to inactivate pathogens in blood components has continued to grow. Several of these proposed approaches have been introduced or are currently in clinical studies. The use of chemical inactivating agents must be considered in terms of the current safety of the blood supply and the potential risks that the introduction of new chemical entities into blood components may carry. The impact which these treatment procedures have on the in vitro and in vivo performance of these products must also be considered relative to the potential benefit of the pathogen inactivation potential they offer. This paper will discuss one possible approach for inactivating pathogens in blood using vitamin B2, Riboflavin, and light. We have used Riboflavin for treating plasma and platelets and evaluated protein quality and platelet function in vitro. Initial toxicology tests to assess the impact of infusion of photoproducts generated in these processes have also been conducted in rodents. Cytotoxicity evaluations have been used to assess the possible impact of photoproduct toxicity in vivo. Virus and bacteria spiking studies using a variety of human and animal model pathogens have been conducted in order to asses the efficacy of this process. Initial toxicology assessment of the photoproducts of Riboflavin generated under the proposed treatment conditions have been favorable. Virus and bacteria clearance studies have demonstrated efficacy of the procedure against a wide range of human and animal pathogens, including intracellular HIV-1. Studies with platelet and plasma function indicated reductions in vitro comparable to other proposed treatment approaches. The use of Riboflavin in a photochemical decontamination process for blood components shows promise.