Lack of antibody formation to platelet neoantigens after transfusion of riboflavin and ultraviolet light-treated platelet concentrates.

Background: Pathogen inactivation technologies provide a potential solution to donor screening and blood testing strategies reducing the risk of transfusion-transmitted infectious diseases. The Mirasol pathogen reduction technology (PRT) system (CaridianBCT) uses riboflavin and UV light to introduce modifications in nucleic acids, reducing the infectious pathogen load in blood components. This study evaluated serum of patients who received PRT-treated platelet (PLT) concentrates over a time period of 28 days for the appearance of antibodies to neoantigens on PLTs.

Study Design And Methods: Serum specimens were obtained at study inclusion and at the 28-day follow-up visit from patients randomly assigned to receive PRT-treated PLT concentrates and at study inclusion of control subjects receiving untreated PLTs. PLT samples from untreated and PRT-treated PLTs were collected. PLT samples for each patient were pooled for the analysis. The presence of antibodies in patient serum to neoantigens was determined with a modified Capture-P assay. The presence of auto- or alloantibodies in specific patient samples was determined with PAKAUTO and PAK 12 techniques.

Results: Forty-four patients receiving PRT-treated PLTs were evaluated; none of these patients demonstrated antibodies to neoantigens. One patient demonstrated a PLT alloantibody to human PLT antigen (HPA)-5b and autoreactivity to glycoprotein Ia/IIa, consistent with an alloantibody at the beginning, but not at the end of the study interval. Of 22 patients evaluated in the control group, one alloantibody with HPA-5b reactivity was detected.

Conclusion: Patients receiving PRT-treated PLT concentrates did not demonstrate antibodies to neoantigens, suggesting that neoantigen formation is not a critical side effect of this pathogen reduction process.