Comparison of flow cytometric assays with isotopic assays of 51chromium-labeled cells for estimation of red cell clearance or survival in vivo

Autor: D.J. Jackson, Belinda M. Kumpel, P.A. Judson, E.B. Austin, D. Lee, G.E. Chapman
Rok vydání: 2000
Předmět:
Zdroj: Transfusion. 40:228-239
ISSN: 1537-2995
0041-1132
DOI: 10.1046/j.1537-2995.2000.40020228.x
Popis: BACKGROUND: A comparison was made between flow cytometric and conventional radioisotopic assays in the determination of the clearance or survival of small volumes of 51chromium-labeled D+ red cells after injection into volunteers. STUDY DESIGN AND METHODS: Four clearance studies were performed using 4 mL of autologous D+ cells coated with anti-D at two concentrations (5 or 10 μg anti-D/mL red cells) transfused to two subjects at separate times. Five survival studies were carried out using 5 mL of frozen-thawed D+ cells transfused to five D– subjects with no detectable anti-D. Sequential blood samples were taken for gamma counting and flow cytometry. Several methods were used to stain the transfused red cells, and the data were analyzed by using three flow cytometers. RESULTS: The determination of red cell clearance or survival by radioactivity measurements gave results consistent with published data. However, none of the flow cytometric assays exhibited the necessary sensitivity or accuracy in quantitation of the rare events to provide reliable data for the calculation of the initial clearance rate, the red cell half-life, or the mean cell lifespan, although rough estimates of red cell clearance were obtained in some subjects. This inability to accurately enumerate rare fluorescence-labeled cells was due mainly to the presence of “background” events, which were a considerable problem in some samples, when the coating level of anti-D was less than 3000 molecules of IgG per cell. CONCLUSION: Flow cytometry may enable the crude estimation of the percentage of small volumes (
Databáze: OpenAIRE
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