Platelet washing with a blood cell processor.

Washing of platelet components for transfusion may be indicated in selected patients. This study was designed to determine a protocol using an automated cell processor to remove plasma proteins from pooled platelet concentrates, stored at 20 to 24 degrees C with constant rotation. A 1500-ml, 0.9% saline-wash procedure is described. Eight percent of the platelets were lost with the procedure (range, 0-19%), while a mean of 99.6 percent of the plasma protein was removed (range, 99.2-99.8%). The clinical effectiveness of maternal platelets washed by this method was demonstrated in a case of alloimmune neonatal thrombocytopenia.