Photochemical inactivation with amotosalen and long-wavelength ultraviolet light of Plasmodium and Babesia in platelet and plasma components.
BACKGROUND
Transfusion-transmitted cases of malaria and babesiosis have been well documented. Current efforts to screen out contaminated blood products result in component wastage due to the lack of specific detection methods while donor deferral does not always guarantee safe blood products. This study evaluated the efficacy of a photochemical treatment (PCT) method with amotosalen and long-wavelength ultraviolet light (UVA) to inactivate these agents in red blood cells (RBCs) contaminating platelet (PLT) and plasma components.


METHODS
Plasmodium falciparum- and Babesia microti-contaminated RBCs seeded into PLT and plasma components were treated with 150 micromol per L amotosalen and 3 J per cm2 UVA. The viability of both pathogens before and after treatment was measured with infectivity assays. Treatment with 150 micromol per L amotosalen and 1 J per cm2 UVA was used to assess the robustness of the PCT system.


RESULTS
No viable B. microti was detected in PLTs or plasma after treatment with 150 mol per L amotosalen and 3 J per cm2 UVA, demonstrating a mean inactivation of greater than 5.3 log in PLTs and greater than 5.3 log in plasma. After the same treatment, viable P. falciparum was either absent or below the limit of quantification in three of four replicate experiments both in PLTs and in plasma demonstrating a mean inactivation of at least 6.0 log in PLTs and at least 6.9 log in plasma. Reducing UVA dose to 1 J per cm2 did not significantly affect the level of inactivation.


CONCLUSIONS
P. falciparum and B. microti were highly sensitive to inactivation by PCT. Pathogen inactivation approaches could reduce the risk of transfusion-transmitted parasitic infections and avoid unnecessary donor exclusions.
Grellier
Philippe
P
Biologie Fonctionnelle des Protozoaires, Muséum National d'Histoire Naturelle, Paris, France.
Benach
Jorge
J
Labaied
Mehdi
M
Charneau
Sébastien
S
Gil
Horacio
H
Monsalve
Gloria
G
Alfonso
Ryan
R
Sawyer
Lynette
L
Lin
Lily
L
Steiert
Matthias
M
Dupuis
Kent
K
D000818:Animals; D041001:Babesia microti / Q000187:drug effects* / Q000254:growth & development / Q000528:radiation effects; D001404:Babesiosis / Q000097:blood* / Q000517:prevention & control / Q000635:transmission; D001781:Blood Component Removal; D016913:Blood Component Transfusion; D001782:Blood Donors; D001792:Blood Platelets / Q000469:parasitology; D004912:Erythrocytes / Q000469:parasitology; D011564:Furocoumarins; D006801:Humans; D016778:Malaria, Falciparum / Q000097:blood* / Q000517:prevention & control / Q000635:transmission; D051379:Mice; D010777:Photochemistry; D010949:Plasma / Q000469:parasitology; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000254:growth & development* / Q000528:radiation effects; D014466:Ultraviolet Rays
D011564:Furocoumarins; C118577:amotosalen