Leukodepletion Filters for Prevention of Transfusion Transmission Of Leishmania

摘要

BACKGROUND: Leishmania is an intracellular parasite of monocytes transmissible by transfusion. The feasibility of reducing Leishmania with leukodepletion filters was studied. At collection, infected blood contains the amastigote form of Leishmania within monocytes. Amastigotes cause the rupture of monocytes releasing free amastigotes that convert to promastigotes which exist extracellularly at blood storage temperatures. Leukodepletion filters were tested at various time points in this process. STUDY DESIGN AND METHODS: Blood products were infected with Leishmania organisms then filtered: (1) using whole blood filters at collection; (2) using bedside filters after storage; and (3) to determine whether free promastigotes could be eliminated. RESULTS: Filtration at collection reduced Leishmania by three to four logs or to the level of detection. Filtration of infected packed red cells after two weeks of storage showed a reduction of Leishmania by four logs. Filtration resulted in a six to eight log reduction in promastigotes in either the presence or in the absence of white cells within the filter. Conclusion: Filtration at the time of collection and after storage of Leishmania infected blood resulted in a substantial reduction of free and intracellular organisms. There is currently no donor screen for Leishmania. Until adequate testing is developed, the use of leukodepletion filters could add to the safety of the blood supply.