(P-TS-8) Amotosalen/UVA Treatment of Human Apheresis Platelets Contaminated with Bacillus mobilis, Acinetobacter seifertii, Staphylococcus saprophyticus, and Leclercia adecarboxylata

The INTERCEPT^® Blood System for Platelets is a PR technology that inactivates pathogens and leukocytes using amotosalen and UVA light. The system is used in the United States and Europe to treat apheresis- and/or whole-blood derived platelets.

BM, AS, SS, and LA were isolated from an INTERCEPT-treated apheresis platelet unit from a TTI case in Ohio, USA. As previously reported, a leak was identified near the platelet unit port, suggesting environmental contamination after PR (Gammon et al., 2022). Prior data show that AS, LA, and SS are inactivated by amotosalen and UVA light. PR was not assessed previously for BM.

Study

Design/Methods:

To measure the effectivity of PR treatment, 3.4 mL of a vegetative culture of BM alone or a 1:1:1:1 (volume) mixture of BM, AS, SS, and LA were inoculated into an apheresis platelet unit (35% plasma/65% Platelet Additive Solution) and treated using amotosalen and UVA light. Bacterial titer was determined pre- and post-treatment and on days 5- and 7-post collection.

Results/Findings:

Amotosalen and UVA light treatment inactivated 3.6 ± 0.1 log cfu/mL of BM alone and 7.0 ± 0.0 log cfu/mL of the mixture of BM, AS, SS, and LA (calculated input titer of 3.0 ± 0.0, 7.5 ± 0.0, 7.4 ± 0.1, and 6.5 ± 0.1 log cfu/mL of BM, AS, SS, and LA, respectively). No bacteria were observed post-treatment, at 5- and 7-days post-collection in either case.

Conclusions:

We show that amotosalen and UVA light treatment inactivates BM alone and in combination with AS, SS, and LA in platelet components, achieving sterility throughout the 7-day storage period.