2026/07/29 by Athinoula Meli, Christian J. Stevens‐Hernandez, Azhar Mohamudally +4
paper · doi:10.1111/trf.70357
Abstract Background Familial pseudohyperkalemia (FP) is an asymptomatic condition characterized by an increased rate of potassium leak from red blood cells (RBC) on refrigeration. The effect of washing on FP RBC was investigated. Study Design and Methods Ten FP and 20 non‐FP individuals were identified from the National Institute for Health and Care Research BioResource. Whole blood was collected and held overnight at 20–24°C, leucocyte‐depleted, and processed into red cell concentrates (RCC) in Saline Adenine Glucose Mannitol before cold storage at 4 ± 2°C. On Day 1, RCC were split into six red cell splits (RCS). Two RCS remained non‐washed, two were washed on Day 2, and two were washed on Day 14. RBC were tested for quality parameters over storage. Results Non‐washed FP RCS had significantly higher supernatant potassium levels than non‐FP throughout 28 days of storage ( p Discussion All refrigerated RBC leak potassium; however, FP RBC leak potassium and reach equilibrium more rapidly than non‐FP. RBC washed on Day 2 still contained a high concentration of potassium and the differential rate of potassium loss between FP and non‐FP RBC post‐wash was as expected. By Day 14, FP RBC lost most of their intracellular potassium and the rate of potassium loss post‐wash was reduced.