Leukocyte Counting During Process Control of Leukoreduced Blood Components

Background And Objectives: To describe the characteristics of counting assays used for process control of leukoreduction.

Materials And Methods: Literature review.

Results: Counting assays with good performance characteristics are an essential element of the process control of leukoreduction. A recent multicenter study by a Working Party of the ISBT has evaluated three widely used methods for counting low numbers of leukocytes in leukoreduced blood.

Conclusion: Automated methods provide greater accuracy and better inter-laboratory precision than Nageotte hematocytometry. However, deterioration of performance as a result of prolonged sample shipment remains an obstacle to centralized testing services. Although several mathematical approaches have been used to model the distribution of residual leukocytes in leukoreduced blood, no single model has been shown to be clearly superior.