Seven-day storage of single donor platelets in polyolefin bags: clinical, biochemical, morphological and microbiological evaluation

We compared the in vitro and in vivo function of fresh and stored platelet concentrates (PCs) collected by an automated continuous-flow blood cell separator (CS 3000 Fenwal) in a closed-system apheresis kit in order to evaluate the possibility of extending the storage time to seven days with the polyolefin container (PL-732). The initial 220 ml platelet volume (5.14 +/- 1.23 x 10(11) was divided into two parts. Half was transfused and the other half was stored for 7 days. All cultured units were negative for bacterial contamination. Mean counts for fresh and stored platelets were respectively 2.34 +/- 0.59 and 2.17 +/- 0.50 X 10(11)/100 ml of PCs (mean recovery 88.7 +/- 11.9%). The pO2 levels were maintained during storage (179.9 +/- 30.5 mmHg) but pCO2, pH, LDH, osmolality, glucose consumption, bicarbonates, ATP, and osmotic stress values changed significantly after 7 days storage. From a clinical point of view, in 14 patients receiving a total of 38 PC transfusions no statistically significant change in corrected post-transfusional levels was observed between fresh and stored PC. Biochemical and morphological data and clinical results suggest that PCs collected with CS-3000 blood cell separator in a closed system and stored for 7 days in polyolefin bags (PL-732) can be satisfactorily employed in clinical practice.