In this study we describe the false-positive frequency in radioimmunoprecipitation assays for muscle acetylcholine receptor (AChR) and neuronal voltage-gated potassium channel (VGKC) autoantibodies, attributable to 125I-ligand immunoprecipitation. Sera were evaluated for AChR autoantibody (n = 34,095) and VGKC autoantibody (n = 11,028). We retested sera that yielded apparently positive results with 1251-ligand with and without detergent-solubilized cation-channel protein and indentified clinically validated fals-positive rates of 0.05% and 1.7% for AchR and VGKC autoantibodies, respectively. Specificity assurance in radioimmunoprecipitation assays requires subtraction of values for 125I-ligand binding.
- Acetylcholine receptor autoantibody
- Myasthenia gravis
- Potassium channel autoantibody
ASJC Scopus subject areas
- Clinical Neurology
- Cellular and Molecular Neuroscience
- Physiology (medical)