Inactivation of Viruses in Platelet Concentrates by Photochemical Treatment with Amotosalen and Long-wavelength Ultraviolet Light

Background: Viral contamination of platelet (PLT) concentrates can result in transfusion-transmitted diseases. A photochemical treatment (PCT) process with amotosalen-HCl and long-wavelength ultraviolet light (UVA), which cross-links nucleic acids, was developed to inactivate viruses and other pathogens in PLT concentrates.

Study Design And Methods: High titers of pathogenic or blood-borne viruses, representing 10 different families, were added to single-donor PLT concentrates containing 3.0 x 10(11) to 6.0 x 10(11) PLTs in approximately 300 mL of 35 percent plasma and 65 percent PLT additive solution (InterSol). After PCT with 150 micromol per L amotosalen and 3 J per cm(2) UVA, residual viral infectivity was assayed by sensitive cell culture or animal systems.

Results: Enveloped viruses were uniformly sensitive to inactivation by PCT whereas nonenveloped viruses demonstrated variable inactivation. Log reduction of enveloped viruses for cell-free HIV-1 was >6.2; for cell-associated HIV-1, >6.1; for clinical isolate HIV-1, >3.4; for clinical isolate HIV-2, >2.5; for HBV, >5.5; for HCV, >4.5; for DHBV, >6.2; for BVDV, >6.0; for HTLV-I, 4.2; for HTLV-II, 4.6; for CMV, >5.9; for WNV, >5.5; for SARS-HCoV, >5.8; and for vaccinia virus, >4.7. Log reduction of nonenveloped viruses for human adenovirus 5 was >5.2; for parvovirus B19, 3.5->5.0; for bluetongue virus, 5.6-5.9; for feline conjunctivitis virus, 1.7-2.4; and for simian adenovirus 15, 0.7-2.3.

Conclusion: PCT inactivates a broad spectrum of pathogenic, blood-borne viruses. Inactivation of viruses in PLT concentrates with amotosalen and UVA offers the potential to prospectively prevent the majority of PLT transfusion-associated viral diseases.