Using label-free quantative proteomics， we have identified 2 potential protein biomarkers that indicate presymptomatic kidney disease in the urine of pediatric patients with type-I diabetes and Fabry disease (n = 20). Prosaposin and GM2 activator protein (GM2AP) were observed to be elevated in the urine of these patient groups compared to age- and sex-matched controls. These findings were validated by development of a rapid MRM-based tandem mass spectrometry test. Prosaposin was observed to be both significantly elevated in the urine of patients with Fabry disease compared to controls (p = 0.02) and reduced after 12 months enzyme replacement therapy (ERT， p = 0.01). Similarly， GM2AP concentrations were ob... More
Using label-free quantative proteomics， we have identified 2 potential protein biomarkers that indicate presymptomatic kidney disease in the urine of pediatric patients with type-I diabetes and Fabry disease (n = 20). Prosaposin and GM2 activator protein (GM2AP) were observed to be elevated in the urine of these patient groups compared to age- and sex-matched controls. These findings were validated by development of a rapid MRM-based tandem mass spectrometry test. Prosaposin was observed to be both significantly elevated in the urine of patients with Fabry disease compared to controls (p = 0.02) and reduced after 12 months enzyme replacement therapy (ERT， p = 0.01). Similarly， GM2AP concentrations were observed to be significantly higher compared to controls in the diabetic group (p = 0.049) and the pretreatment Fabry group (p = 0.003). In addition， this observed to be reduced significantly in the Fabry group following 12 months of ERT (p = 0.01). The process of detection of the biomarkers， development into a test and implications for monitoring patients and treatment are discussed.
