Flow-cytometric method for the quantitation of the Fc function of intravenous immunoglobulin preparations

Abstract

Objectives: We have developed and optimised a new flow-cytometric method for the measurement of the Fc function of intravenous immunoglobulin (IVIg) preparations, which is important in predicting the effector function of immunoglobulin (lg) in such preparations. Materials and Methods: lg was bound to a monocytic cell line, THP-1 with FcγRI and FcγRII cell surface receptors, and the bound lg detected by FITC-conjugated F(ab)2 fragment of rabbit anti-human lgG. Results: Validation studies showed that lg bound to the cell line through the Fc portion. The method detected alterations in Fc function caused by reduction with dithiothreitol or by storage. The method was reproducible (CV<11%) and a limited comparison study showed that it correlated with the European Pharmacopoeia reference method. Conclusions: This technically simple method is suitable for the quantitation of the Fc function of lg preparations. Copyright (C) 2000 S. Karger AG, Basel.