A pilot study to assess the hemostatic function of pathogen-reduced platelets in patients with thrombocytopenia
- Research funding for this study was provided by Terumo BCT to PIJ.
Address reprint requests to: Pär I. Johansson, Department of Clinical Immunology, Rigshospitalet 2034, Blegdamsvej 9, 2100 Copenhagen, Denmark; e-mail: firstname.lastname@example.org.
Platelet (PLT) support is critical to the care of patients with thrombocytopenia, but allogeneic transfusions carry risk. Pathogen reduction mitigates some transfusion risks, but effects on PLT function remain a concern. This clinical pilot study assessed the effect of pathogen reduction technology with riboflavin plus ultraviolet light using thrombelastography (TEG).
Study Design and Methods
This prospective, randomized, crossover study compared Mirasol-treated (MIR) and standard reference (REF) PLT transfusions. PLT counts and TEG measurements were taken at pretransfusion and 1- and 24-hour-posttransfusion time points. The primary outcome measure was the pretransfusion to 1-hour-posttransfusion change in maximum amplitude (ΔMA1hr). Secondary endpoints included ΔMA among other time points, relative MA, and the PLT count–MA correlation.
Of 16 enrolled patients, one withdrew before study treatment and three did not require two transfusions, leaving 12 patients in the efficacy analyses (seven MIR-REF, five REF-MIR). ΔMA1hr (mean ± SD) was 10.60 ± 6.47 mm for MIR and 14.33 ± 5.38 mm for REF (p = 0.20, n = 10). ΔMA24hr was 9.49 ± 7.94 for MIR and 7.13 ± 3.08 for REF (p = 0.38, n = 9); ΔMA24hr-1hr was −1.11 ± 2.95 for MIR and −7.20 ± 4.81 for REF (p = 0.016, n = 8). MA values for MIR and REF correlated with the log of PLT count (rMIR = 0.6901, rREF = 0.7399).
TEG is sensitive to changes in hemostatic function resulting from a single PLT transfusion. MIR and REF provided similar increments in hemostatic function in the immediate posttransfusion period and at 24 hours. A significant difference detected for ΔMA24hr-1hr suggests different PLT clearance mechanisms. The relationship of these variables to clinically meaningful outcomes, for example, bleeding events or transfusion requirements, has yet to be determined.