Serum Disease-specific IgG Fc Glycosylation as Potential Biomarkers for Nonproliferative and Proliferative Diabetic Retinopathy Using Mass Spectrometry

The patients were enrolled and categorized into three groups according to clinical diagnosis: non-diabetic retinopathy; nonproliferative diabetic retinopathy ; and proliferative diabetic retinopathy. Gel electrophoresis was performed to separate IgG from morning fasting blood samples and polyaniline magnetic nanomaterials (Fe3O4@PANI) were used to enrich IgG N-glycopeptides from tryptic digestion. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI ToF MS) was used to detect the IgG N-glycopeptides.