GAST and myasthenia gravis: These corresponded to detection sensitivities and specificities of 61.6% and 80.0% for PGI levels, 69.2% and 72.0% for PGI levels, 30.7% and 100% for PGI levels, 38.4% and 76.0% for PG II levels, demonstrating the clinical value of gastrin for predicting MG.