Leishmania inactivation in human pheresis platelets by a psoralen (amotosalen HCl) and long‐wavelength ultraviolet irradiation

Abstract

This study demonstrates the effectiveness of photochemical treatment to inactivate Leishmania in PLT concentrates intended for transfusion. Both metacylic promastigotes, which represent the infectious form from the sand fly vector, and amastigotes, which represent the form that grows in mononuclear phagocytes, were extremely susceptible to photochemical inactivation by this process. Thus, the photochemical treatment of PLT concentrates inactivates both forms of Leishmania that would be expected to circulate in blood products collected from infected donors.

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].…”

“…The system has been successfully used to inactivate a broad spectrum of viruses, bacteria, and parasites (such as Leishmania), in platelet components, not affecting their function and/or structural features. However, this technology is not effective for red blood cells or whole blood, because the UV light does not manage to penetrate sufficiently to activate the amotosalen, and induce nucleic acid cross-linking [106,107].…”

Arboprotozoen

“…Inaktivierung ist ebenfalls möglich durch Behandlung mit Psoralen und UV-Licht, wobei 4 log 10 reduziert wurden [47]; und mit Riboflavin und UV-Licht, wobei eine Reduktion von etwa 5 log 10 in Plasma und Thrombozytenkonzentraten erreicht wurde [48].…”

Arboprotozoae

“…Leishmania can be inactivated by DNA intercalating photoinactivators such as thiopyrilium after light irradiation by more than 5.7 log 10 TCID 50 [46]. Inactivation can also be carried out by treatment with psoralen and UV light, bringing about a reduction of 4 log 10 [47], and riboflavin and UV light, in which case a reduction of approximately 5 log 10 in plasma and platelet concentrates was achieved [48]. Leishmanias can be removed entirely by sterile filtration and do therefore not have any significance for plasma derivatives.…”