Pathogen inactivation of Leishmania donovani infantum in plasma and platelet concentrates using riboflavin and ultraviolet light

Abstract

Background and Objectives Leishmania is transmitted by the bite of the phlebotomine sandfly or by transfusion of infected blood products. Leishmaniasis currently poses a significant problem in several parts of the world, and is an emerging problem in others. The Mirasol PRT technology is based on the use of riboflavin and ultraviolet light to generate chemical reactions in the nucleic acids of pathogens, which prevents replication and leads to inactivation. The intent of this study was to examine the ability of the Mirasol PRT System to kill the Leishmania parasite in human plasma and platelet concentrates. Materials and Methods In visceral Leishmaniasis, amastigotes are present in the blood and in the reticuloendothelial system within monocytes. For each unit of plasma or platelets treated, isolated mononuclear cells obtained from 100 ml of normal donor whole blood were incubated with 1·0 × 108Leishmania donovani infantum promastigotes to produce amastigote‐laden macrophages. The infected macrophages were added to 250 ml of human plasma or to 250 ml of platelet concentrates. Infected units were cultured pretreatment in 10‐fold serial dilutions to determine the limits of detection. Thirty millilitres of 500 µm riboflavin was added to each unit, which was then illuminated with 5·9 J/cm2 of ultraviolet light (6·24 J/ml). After treatment and after 2 months of frozen storage, plasma units were cultured in 10‐fold serial dilutions. Platelets were cultured on the day of treatment and on day 5 of storage post‐illumination. Results A 5 log reduction of Leishmania was demonstrated in five of six units of plasma, and a 7 log reduction of Leishmania was demonstrated in one plasma unit. A 5 log reduction of Leishmania was demonstrated in five of six units of platelets, and a 6 log reduction of Leishmania was demonstrated in one unit. Conclusions There is no donor screen for Leishmania and other pathogens constantly emerging in our blood supply. The Mirasol PRT System for Platelets and Plasma is an effective means of killing Leishmania and other emerging pathogens in these blood products.

Quality control of riboflavin-treated platelet concentrates using Mirasol® PRT system: Polish experience

“…Multicenter trials by Cardo et al have shown the riboflavin method to be effective for killing Leishmania and other emerging plasma and platelet pathogens (5-7 log reduction). 6,7 Numerous studies have also confirmed this method to be effective for white blood cell inactivation. Clinical trials have proved the safety of Mirasol ® PRT system-treated blood components and lack of neoantigen formation.…”

Treatment of Platelet Products with Riboflavin and UV Light: Effectiveness Against High Titer Bacterial Contamination

“…Using riboflavin as a photosensitizer, in combination with UV light, has been shown to reduce the infectivity of a broad range of pathogenic blood-borne contaminants, including bacteria 3,4,8,10,[19][20][21] .The use of riboflavin and UV light for pathogen reduction is non-toxic and non-mutagenic, and riboflavin and UV light-treated components have been shown to be safe for transfusion recipients as well as for those handling blood products 18 . Briefly, riboflavin molecules can associate with the nucleic acids (DNA and RNA) of bacteria, parasites, viruses and any nucleated cell (e.g.…”

Transfusion transmitted leishmaniasis. What to do with blood donors from endemic areas?

“…Recently, using in vitro experiments several methods designed to inactivate Leishmania in blood products have been tested. These include the use of riboflavin (as a photosensitizer) and ultraviolet light [105], and the photochemical treatment by amotosalen plus ultraviolet light in platelet concentrates [106,107] as well as by thiopyrylium in RBC suspensions [108].…”

“…As a result of these photochemical processes, pathogens in blood products are rendered unable to replicate due to nucleic acid modification. This technology exploits the absence of nucleic acids in all the blood components (including plasma and platelet concentrates), which are beneficial to transfusion, and that instead is present in the parasite [105,109].…”