Sodium citrate contributes to the platelet storage lesion

Abstract

BACKGROUND: Sodium citrate has become the preferred anticoagulant used for apheresis collection and has been included in commercial platelet additive solutions (PASs) since PAS-II. It was suggested that citrate be included in PASs to prevent spontaneous aggregation. Reports in cell lines and cord blood have demonstrated that concentrations of citrate present in PAS formulations (10 mM) cause apoptosis. We evaluated whether the removal of citrate from PAS-III could improve platelet storage. STUDY DESIGN AND METHODS: Study 1 evaluatedthe effects of a citrate dose response on the storage of platelets in 65% PAS containing sodium chloride, sodium acetate, and phosphate. Study 2 compared the cell quality and function of platelets stored in 65% citrate-free PAS-III or PAS-III containing 10 mM of citrate. Measurements included cell count, blood gases, flow cytometry analysis of surface activation markers, and aggregation. RESULTS: Study 1 identified that inclusion of citrate in PAS resulted in a dose-dependent increase in glucose utilization, lactate formation, P-selectin expression, phosphatidylserine (PS) exposure, and reactive oxygen species (ROS) formation. Study 2 showed similar results in which platelets stored in citrate-free PAS-III benefited through better maintenance of glucose utilization with less lactate production, P-selectin expression, PS exposure, and ROS formation compared to citratecontaining PAS-III. Platelets stored in citrate-free PAS-III had aggregation responses that were at least 10% greater than those platelets stored in PAS-III. CONCLUSION: Storage of apheresis platelets incitrate-free PAS-III improved multiple storage parameters including glucose utilization, lactate production, Pselection expression, PS exposure, and ROS formation and resulted in a modest increase in aggregation.ABBREVIATIONS: ACD = anticoagulant citrate dextrose solution; ADP = adenosine diphosphate; CPD = citrate-phosphate-dextrose; PASs = platelet additive solutions; PS = phosphatidylserine; ROS = reactive oxygen species; TRAP6 = thrombin receptor activator peptide 6.* Significantly different than Day 5, 0 mM citrate bicarbonate levels; one-way analysis of variance, p = 0.029. † Significantly different than Day 5, 0 mM citrate bicarbonate levels; one-way analysis of variance, p = 0.003.

Preliminary characterization of the properties of cold‐stored apheresis platelets suspended in PAS‐III with and without an 8‐hour room temperature hold

“…Several observations in this study have been noted in other studies of cold storage of PLTs including increases in PLT activation, phosphatidylserine exposure, and ROS during storage 10‐12 . In addition, increases to ADP induced aggregation were observed during storage ( P < .05).…”

“…Several observations in this study have been noted in other studies of cold storage of PLTs including increases in PLT activation, phosphatidylserine exposure, and ROS during storage. [10][11][12] In addition, increases to ADP induced aggregation were observed during storage (P < .05). This small increase could be caused by the cold-induced calcium leak, leading to partial and slow activation of the fibrinogen receptor as measured by PAC1, making PLTs primed for aggregation induced by a relatively weak ADP agonist.…”

“…PLT surface markers and reactive oxygen species (ROS) markers were measured by flow cytometry (FACSCalibur, BD Biosciences) as previous described 10 . Briefly, PLTs were diluted to 1 × 10 6 PLTs/mL in PBS with 0.1% human serum albumin and incubated with CD61‐PerCP/CD62‐PE/CD42b‐FITC at saturating concentration at room temperature for 15 minutes.…”

“…PLT surface markers and reactive oxygen species (ROS) markers were measured by flow cytometry (FACSCalibur, BD Biosciences) as previous described. 10 Briefly, PLTs were diluted to 1 × 10 6 PLTs/mL in PBS with 0.1% human serum albumin and incubated with CD61-PerCP/CD62-PE/CD42b-FITC at saturating concentration at room temperature for 15 minutes. PLTs No differences were observed in CD62P (p-selectin), CD42b (glycoprotein 1b alpha chain), annexin V (phosphatidylserine exposure), or CM-H2DCFDA (reactive oxygen species levels) comparing units held with an 8-hour room temperature hold to those without a hold (Table 1).…”

Removal of citrate from PAS‐III additive solution improves functional and biochemical characteristics of buffy‐coat platelet concentrates stored for 7 days, with or without INTERCEPT pathogen reduction

“…This positive effect on platelet function at later times of storage is probably the consequence of the decreased metabolic demand with better maintenance of pH and reduced spontaneous activation of BC-PCs. In comparison, only a modest improvement in aggregation up to Day 5 has been reported for apheresis-derived PCs stored in citrate-free PAS-III, 29 most likely because apheresis causes more activation of platelets than BC collection methods. 30 Overall, our results indicate that removal of citrate from PAS-III additive solutions has a beneficial impact on several storage parameters of BC-PCs, affording a reduction in anaerobic glycolysis, spontaneous activation and apoptosis, and an improvement in platelet aggregation in vitro in response to various agonists over 7 days.…”