ABSTRACT
BACKGROUND: This study aimed to analyze the influence of the interruption of agitation and removal of leukocytes on platelet concentrates (PCs), and determine the maximum amount of time the agitation could be interrupted without impairing PCs' effectiveness during the storage period. METHODS: Four ABO-identical random donor platelets agitated for 24 hr were pooled, and divided into 4 units, and 2 units of them were leukoreduced. Then 52 pooled units were categorized into 4 groups, non-leukoreduced continuous agitation (Non-LRCA), non-leukoreduced interrupted agitation (Non-LRIA), leukoreduced continuous agitation (LRCA), and leukoreduced interrupted agitation (LRIA), and preserved for 6 days (total 7 days). Mean platelet volume (MPV), pH, HCO3-, pO2, pCO2, CD62P, CD61, glucose, lactate, ammonia and free fatty acid were measured during the period. RESULTS: Starting from the Day 4, the pH and HCO3- of Non-LRIA group begun to decrease while the amount of lactate production, glucose consumption, and MPV increased compared to the Non- LRCA group (P<0.01). An increase in pO2 level was observed in the interrupted agitation groups as the storage period prolonged (P<0.01). The pH levels of all the units in the agitation groups remained higher than 6.4 up to Day 7, while those of the non-leukoreduction group did so only up to Day 2, but those of leukoreduction in the interrupted agitation groups did so up to Day 4. CONCLUSIONS: The interruption of agitation reduced the platelet's capacity to utilize oxygen, increasing lactate amount and reducing pH level. However, the in vitro parameters of the Non-LRIA and Non-LRCA groups on Day 2 were similar to each other and the pH level remained at 6.4 or higher, making one day of agitation interruption possible after 24 hr of agitation. With leukocytes removed, the effective agitation interruption period may become longer.