Characteristics of lymphocytes and granulocytes removed from whole blood by buffy coat depletion. Comparison of an automated bottom-and-top processing system and the manual technique

Background. Characteristics of lymphocyte and granulocyte removal were stud ied during the processing of fresh human blood by buffy coat (BC) depletion . Methods. The manual technique of BC depletion and that performed in a botto m-and-top (BAT) semiautomated system were compared. Blood cells were counte d in the resulting components. Results. Removal efficiency in lymphocytes and granulocytes correlated to t he loss of erythrocytes due to removal of the BC, Sigmoidal curves showed g ood fit to experimental data. Variables of the equations differed substanti ally concerning removal of lymphocytes and granulocytes. The bottom-and-top bag in the semiautomated system resulted in better efficiency in leukocyte removal compared to the conventional manual technique. Conclusions. With a red cell loss of <10% of donated red cells, >98% of lym phocytes may be removed from whole blood in the semiautomated BAT system. R emoval efficiency of granulocytes is inferior compared to that of lymphocyt es. Performance characteristics of the semiautomated BAT technique appeared superior when compared to the conventional manual technique. Substantial v ariability was observed in granulocyte removal efficiency in both systems. The present study may contribute to the production of erythrocyte preparati ons with less contaminating leukocytes and to standardize semiautomated blo od processing. (C) 2000 IMSS. Published by Elsevier Science Inc.