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 × 1011 to 6.0 × 1011 PLTs in approximately 300 mL of 35 percent plasma and 65 percent PLT additive solution (InterSol). After PCT with 150 µmol per L amotosalen and 3 J per cm2 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.