Virus inactivation of platelet concentrates by photochemical treatment with S-59

Purpose: Photochemical treatment (PCT), using psoralen (S-59) in conjunction with UVA-light, provides a new method for inactivation of bacteria, viruses and leukocytes in platelet concentrates. Extensive modification by S-59 on DNA and RNA prevents replication of the genome while non-nucleated platelets are uneffected. Methods: We evaluated the effect of PCT on apheresis platelet concentrates. PCs containing 6-6.5 × 10¹¹ platelets in 600 ml of 40% autologous plasma and 60% platelet addirve solution (PASIII). Each product was split into two (each n=8), one for a Control and one for a PCT treated group (Test). Investigations were carried out before, after PCT, and after 5 days of storage. Results: Measurement Control/Test Before PCT Control/Test After PCT Control/Test Day 5 CD62p(%) 40.9/44.1 41.8/38.6*29.9/31.1 hypotonic shock response(%) 39.9/41.8 41.3/49.2*36.3/36.8 shape change 0.95/1.12 0.97/0.82 0.25a/0.18a morphology score 333.9/328.6 330.9/3435*301.0/308a LDH (IU/L) 56.3/55.5 60.5/141.6*103.6a/174.5*a*p<0.05, compared Control vs Test, a p<0.05, compared vs before PCT Conclusion: The photochemical treatment with S-59/UVA offers a valid method for virus inactivation of platelet concentrates. We found no obvious long-term effects on the platelets, although some activation parameters were increased immediately after PCT. In vivo studies a currently underway to determine the hemostatic efficacy of PCT-platelets.