Platelets photochemically treated with amotosalen HCl and ultraviolet A light correct prolonged bleeding times in patients with thrombocytopenia

Abstract

Photochemical treatment (PCT) with amotosalen HCl with ultraviolet A illumination inactivates pathogens and white blood cells in platelet (PLT) concentrates. In a Phase II crossover study, 32 patients with thrombocytopenia received one transfusion of PCT and/or one transfusion of untreated (reference) apheresis PLTs. Hemostatic efficacy was assessed with the cutaneous template bleeding time and clinical observations. Paired bleeding time data for PCT and reference transfusions were available for 10 patients. Mean pretransfusion bleeding times were 29.2 +/- 1.6 minutes in the PCT group and 28.7 +/- 2.5 minutes in the reference group. After transfusion of a dose of PLTs of at least 6.0 x 10(11), mean 1-hour posttransfusion template bleeding times corrected to 19.3 +/- 9.5 minutes in the PCT group and 14.3 +/- 6.5 minutes in the reference group (p = 0.25). In 29 patients receiving paired PCT and reference transfusions, mean 1-hour posttransfusion PLT count increments were 41.9 x 10(9) +/- 20.8 x 10(9) and 52.3 x 10(9) +/- 18.3 x 10(9) per L for PCT and reference, respectively (p = 0.007), and mean 1-hour posttransfusion PLT corrected count increments (CCIs) were 10.4 x 10(3) +/- 4.9 x 10(3) and 13.6 x 10(3) +/- 4.3 x 10(3) for PCT and reference, respectively (p < 0.001). The time to next PLT transfusion was 2.9 +/- 1.2 days after PCT transfusions versus 3.4 +/- 1.3 days after reference transfusions (p = 0.18). Clinical hemostasis was not significantly different after PCT and reference transfusions. PCT PLTs provided correction of prolonged bleeding times and transfusion intervals not significantly different than reference PLTs despite significantly lower PLT count increments and CCIs.