LRP4 Antibodies in Suspected Myasthenia Gravis Diagnosis

This multicenter study investigates the prevalence and diagnostic utility of LRP4 antibodies in patients with suspected myasthenia gravis (MG). By comparing three different cell-based assay (CBA) protocols, researchers found that these antibodies are rare, appearing in only 2% of MG cases and even in some patients with unrelated neurological disorders. The results were highly inconsistent across testing methods, with the most common positive signals failing to appear when using live cell assays. These discrepancies suggest that methanol fixation may create false positives by exposing non-native protein structures. Consequently, the authors conclude that routine LRP4 testing currently lacks clinical value due to poor reproducibility and limited specificity. The findings emphasize an urgent need for standardized testing protocols before LRP4 can be considered a reliable biomarker for the disease.