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 TE671 cell line as a practical alternative to human muscle for monitoring the anti-AChR antibody assay in sera of Myasthenia gravis patients has been recently proposed. Most of the TE671 culture protocols include the use of glucocorticoids. Glucocorticoids were shown to upregulate the acetylcholine receptor expression in TE671 cells. To confirm the advantage of using AChR from TE671 cells (AChRTE) and to validate the use of AChR from glucocorticoid-treated cells (AChRGT) in AChR antibody measurement, the three different antigens (muscle AChR (AChRMU), AChRTE, and AChRGT) were compared for radioimmunoprecipitation assay. We found that, despite a slight underestimation of the antibody titers using AChRTE and AChRGT compared to AChRMU, and considering the rare cases of AChRMU antibody titer category permutations, the correlations between the values were satisfactory.