Effect of white cells on platelets during storage

Abstract

White cells (WBCs) present in stored platelet concentrates have adverse effects on platelet function and on posttransfusion recovery. Although these effects have been attributed to the fall in pH that results from active WBC metabolism, platelets stored in gas-permeable storage bags still exhibit abnormalities, despite maintenance of a stable pH of greater than 6.0. The changes in platelet proteins and function brought about by storage with a controlled number of WBCs were studied. Twelve platelet-pheresis specimens were centrifuged at 180 x g to achieve a WBC count of less than 2 x 10(5) per mL (which contained less than 10% granulocytes). These specimens were split into two aliquots and placed in platelet bags for storage at 22 degrees C with constant horizontal agitation. Neutrophils, obtained from the same donor by centrifugation of 50 mL of whole blood through a discontinuous ficoll gradient, were added to one of the two platelet storage bags to achieve a final neutrophil count of 1 x 10(6) per mL. Platelet aliquots were removed and studied on Days 3 and 5. In platelets stored without neutrophils, the average response to ristocetin, using the mean slope as an index of platelet responsiveness, was 10.3 (n = 9, SD = 11) on Day 3, whereas for the platelets stored with neutrophils, it was 1.25 (n = 12, SD = 0.9, p less than 0.01). Significant differences were also seen on Day 5 (slope = 4.5 for platelets stored without neutrophils, slope = 0.3 for platelets stored with neutrophils, p less than 0.01). Platelet aggregation with 8 microM ADP and 1.5 mg per mL of collagen did not differ significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukocyte Depletion and Storage of Single-Donor Platelet Concentrates

“…After 5 days of storage all parameters con-contamination than we measured in our PCs, we could not demonstrate a beneficial effect of prestorage leukocyte de pletion of PCs on pH and pC02. In agreement with our find ings Dzik et al [14] could not show a positive influence of prestorage leukocyte depletion on in vitro platelet function, which had been reported by another group [20]. Sloand and Klein [20] demonstrated a decreased platelet aggregation responsiveness to ristocetin in PCs stored for 3 days with a very high contamination of neutrophil granulocytes of 1,000/pl compared to leukocyte-poor PCs.…”

“…This concentra tion of granulocytes results in a total granulocyte count of 2.5xlO8 in a PC of 250 ml. This effect could not be repro duced with a 10-fold higher lymphocyte contamination of 10,000/pl, indicating that neutrophils may be responsible for this impairment of platelet function [20]. We observed a leukocyte concentration of 168±56/pl as shown in table 1, but we performed no differentials.…”

“…There are several reports investigating the quality of pla telets after filtration and during subsequent storage in PCs manufactured from whole blood donations [14][15][16][17][18][19], but lit tle is known about the quality of platelets in single-donor PCs prepared by plateletpheresis under these conditions [20][21][22][23]. Due to the possibilities of modem cell separators the leukocyte contamination in unfiltered PCs has under gone a remarkable decrease and is now much lower com pared to those in PCs manufactured from buffy coat or pla telet-rich plasma (PRP).…”

Benefit of Prestorage Leukocyte Depletion of Single–Donor Platelet Concentrates

“…Filter plugging started at day 3 of storage and tended to increase with longer storage (days 4 and 5). The drop in pH is partially related to the metabolism of WBCs, but this is not the only explanation, because even after the addition of WBCs to PCs the pH never dropped below 6.0 [7]. It may also be that increased platelet activation leading to plugging in TH is partially the cause of this important drop in pH.…”

“…WBCs can affect platelet quality during storage. The increase in some cytokines [tumor necrosis factor–α (TNF–α), interleukin 1 (IL–1), interleukin 6 (IL–6) and interleukin 8] during storage of platelets may be partially responsible for febrile nonhemolytic transfusion reactions (FNHTR) [7, 8, 9, 10]. For all these reasons, WBC filtration of blood products has increased and a recent report points out the potential benefit of leukodepletion of blood products [11].…”