Colonic mucosal α-synuclein lacks specificity as a biomarker for Parkinson disease

We are currently investigating colonic biopsies from patients with Parkinson disease (PD) and healthy controls (HC) participating in the Discovery study.1 Our findings partially agree with those of Visanji etal.2 Specifically, we found that immunohistochemistry using antibodies for nonphosphorylated but also phosphorylated forms of alpha -synuclein does not allow accurate and reliable distinction between PD and HC groups.