Preparation of Small Volume,Leuko and Erythrocyte Very Poor Platelet Concentrates

Abstract

Recently developed automated discontinuous flow centrifuge (DFC) separators can produce leuko- and erythrocyte-poor platelet concentrates (PC). According to general experience with these machines it is difficult to obtain more than 4 × 10¹¹ platelets, though a second program set up by Coffe et al. appears to produce PC containing approximately 5 × 10¹¹ platelets suspended in a plasma volume of 390 ml. At our center we employed a new Dideco cell separator equipped with the surge pump and a technique developed for the production of small volume, RBC and WBC-very poor PC. In 60 routine procedures we obtained the following results: mean processing time 87 ±11 minutes; final volume of PC 136 ± 19 ml, with a mean platelet yield of 5.21 × 10¹¹ platelets. WBC contamination was 1.8 × 10⁸ (93% lymphocytes) and RBC were 3.1 × 10⁸. Plasma volume as well as WBC and RBC contamination were reduced by recirculating PC after the 6th pass.

The demand for single donor platelet concentrates (PC) is increasing progressively. Recently developed automated cell separators can produce leukocyte (WBC) and erythrocyte (RBC) poor PC. With these machines it may be difficult to obtain PC containing at least 4 × 10¹¹ platelets and less than 1 × 10⁹ leukocytes (1, 2, 3) since donor variables such as hematocrit, precounts, buffy coat formation and initial plasma light transmission are of paramount importance for the efficiency of the program (3). At our center a prototype discontinuous flow centrifuge (DFC) cell separator equipped with the surge pump was studied (4). It produced PC containing 3.58 ±1.5 × 10¹¹ platelets suspended in a mean of 346.32 ± 51.7 ml of plasma and contaminated by 0.63 ± 0.51 × 10⁹ WBC (95% lymphocytes). The quality of the PC was satisfactory, with good maintenance of platelet functions as measured by ristocetin-induced aggregation and malonaldehyde production, but our study brought to light the main limitations of the system, namely the variability of WBC and RBC contamination and the excessive loss of plasma.

In this study we report on a technique developed with the Unicell prototype to produce small volume, WBC and RBC-very poor PC.