Platelet activation during plasma-reduced multicomponent PLT collection: a comparison between COBE Trima and Spectra LRS turbo cell separators.

BACKGROUND: The wide diffusion of multicomponent collection in donor apheresis has led to the yielding of different components, such as plasma-reduced platelet-pheresis at high PLT concentration. We investigated whether this collection modality could induce more PLT activation compared to standard plateletpheresis. STUDY DESIGN AND METHODS: Forty-one plateletpheresis collections (20 Trima and 21 Spectra LRS Turbo v.7.0, COBE) were evaluated. Donor, procedure, and product data were recorded. ADP, collagen, and U46619 (a thromboxane-A2 analog)-induced PLT aggregation was investigated in basal (donor) and final (plateletpheresis unit) samples. The expression of PLT activation marker P-selectin (CD62P) was studied using flow cytometry in basal and final samples. In all cases, P-selectin was investigated in final samples after stimulation with ADP to assess for a possible further release of the antigen. Four additional plateletpheresis procedures were performed in donors from Group A, using the traditional, nonplasma-reduced program. RESULTS: Plateletpheresis obtained by means of the Trima device showed a lower response to in-vitro induced PLT aggregation and a higher percentage of P-selectin-expressing PLT when compared to products obtained using the Spectra device. Moreover, P-selectin release after ADP stimulation was reduced in plateletpheresis units obtained using the Trima device. These differences disappeared when a nonplasma-reduced collection program was used. In-vivo evaluation did not detect any difference between plateletpheresis obtained by means of the two cell separators. CONCLUSIONS: Plateletpheresis units obtained by means of multicomponent collection show a higher degree of PLT activation compared to traditional plateletpheresis procedures when high-concentration plasma-reduced products are collected. Randomized clinical studies are needed to assess the real impact of these findings in terms of in-vivo efficacy of plasma-reduced plateletpheresis units.

Lymphocyte subsets in inline filtered packed red blood cell units: comparison between low and high spin procedures.

Lymphocyte subsets were determined in 20 packed red blood cell units (PRC) before and after filtration (FPRC) with the Pall Leukotrap RC inline filter system; 10 units were prepared by low spin and platelet rich plasma (PRP) removal (Group A) and 10 with high spin, plasma and buffy-coat (BC) removal (Group B). Flow cytometry was employed for white blood cell (WBC) enumeration and phenotype analysis. Median WBCs in prefiltered units was 2.08 x 10(9) (Group A) vs. 0.8 x 10(9) (Group B) (p < 0.0001). Five Group A and three Group B filtered units had WBC counts above the limit of detection (LD), median values being 25.59 and 3.08 x 10(3), respectively. Whereas CD3+, CD3+CD4+ and CD3+CD8+ lymphocyte subsets were assessable in 20-40% of Group A units, inline filtration of Group B units lowered lymphocytes below the LD of the present study. Post-filtration CD19+ lymphocytes were below the LD in all the 20 units.