Korean J Blood Transfus.  2007 Dec;18(3):194-201.

Measurement of the Residual Leukocyte Count by Flow Cytometry in Leukocyte-reduced Blood Components

• Lee WM
• Kim JH
• Ryoo NH
• Ha JS
• Jeon DS
• Kim JR
• Park SJ
• Kim EJ

Abstract

BACKGROUND: Counting methods for residual leukocytes in leukocyte-reduced blood components include the manual assay using a Nageotte hemocytometer, flow cytometry (FCM) and polymerase chain reaction (PCR). The Nageotte hemocytometer is the most widely used technique in Korea, but it is time consuming and dependent upon the skill of the examiner. We examined residual leukocytes count using a hemocytometer and FCM and compared the accuracy of the use of both methods.
METHODS
Twenty units of RBC concentrates (RCs) were collected in quadruple top-to-bottom collection bags of the Green Cross (Green Cross, Eumsung, Korea) and from BD (Becton Dickinson Korea, Gumi, Korea). Thirty-five units of single donor platelets (SDPs) collected by Amicus (Baxter, Deerfield, IL USA), MCS+ (Haemonetics, Braintree, MA, USA) and Trima (Gambro BCT, Lakewood, CO, USA) were used to measure residual leukocytes using a hemocytometer and FCM using the LeucoCOUNT system (BD Bioscience, San Jose, CA USA).
RESULTS
Linearity of the LeucoCOUNT system was well maintained (R2=0.9998). Reproducibility was CV of 5.08% for 53.01/microlitermicroliter and 8.54% for 4.97/microliter. The hemocytometer measured lower leukocyte counts in all RCs and SDPs than the LeucoCOUNT system. The mean residual leukocyte counts in RCs measured by the hemocytometer were 0.075x10(6)/unit with the Green Cross collection bags and 0.067x10(6)/unit with the BD collection bags, but were 2.301x10(6)/unit and 1.943x10(6)/unit, respectively, when measured with use of the LeucoCOUNT system. The mean residual leukocyte count in the SDPs collected by Amicus, MCS+ and Trima, as measured by the hemocytometer, were 0.037x10(6)/unit, 0.046x10(6)/unit and 0.043x10(6)/unit, respectively. The mean residual leukocyte count in the SDPs collected by Amicus, MCS+ and Trima, as measured by the LeucoCOUNT system, were 0.061x10(6)/unit, 0.161x10(6)/unit and 0.045x10(6)/unit, respectively.
CONCLUSION
The use of the flow cytometric method is moresensitive and produces an accurate leukocyte count in leukocyte-reduced blood components than the use of themanual method.

Keyword

Flow cytometry; Nageotte hemocytometer; Residual leukocyte; Blood components

MeSH Terms

Flow Cytometry*
Gyeongsangbuk-do
Humans
Korea
Leukocyte Count*
Leukocytes*
Polymerase Chain Reaction
Tissue Donors