MYASTHENIA-GRAVIS - COMPARATIVE AUTOANTIBODY ASSAYS USING HUMAN MUSCLE, TE671, AND GLUCOCORTICOID-TREATED TE671 CELLS AS SOURCES OF ANTIGEN

The use of acetylcholine receptors (AChR) from the readily available T E671 cell line as a practical alternative to human muscle for monitori ng the anti-AChR antibody assay in sera of Myasthenia gravis patients has been recently pro posed. Most of the TE671 culture protocols inclu de the use of glucocorticoids. Glucocorticoids were shown to upregulat e the acetylcholine receptor expression in TE671 cells. To confirm the advantage of using AChR from TE671 cells (AChR(TE)) and to validate t he use of AChR from glucocorticoid-treated cells (AChR(GT)) in AChR an tibody measurement, the three different antigens (muscle AChR (AChR(MU )), AChR(TE), and AChR(GT)) were compared for radioimmunoprecipitation assay. We found that, despite a slight underestimation of the antibod y titers using AChR(TE) and AChR(GT) compared to AChR(MU), and conside ring the rare cases of AChR(MU) antibody titer category permutations, the correlations between the values were satisfactory. (C) 1995 Academ ic Press, Inc.