No evidence of pancreatic ductal adenocarcinoma specific autoantibodies to Ezrin in a liquid phase LIPS immunoassay

BACKGROUND: Sensitive and specific biomarkers of Pancreatic Ductal Adenocarcinoma (PDAC) are desperately needed to allow early diagnosis and improve patient's survival. Ezrin autoantibodies were recently described as present in 93% of PDAC patients and 40% of healthy subjects who later developed PDAC. However, another prospective study failed to replicate these findings. Both studies were based on the use of a solid phase ELISA immunoassay. OBJECTIVE: We aimed at re-evaluating the usefulness of Ezrin autoantibodies as PDAC biomarkers using the Luciferase Immuno Precipitation System (LIPS), an alternative immunoassay format that found successful application for the measurement of autoantibodies against pancreatic autoantigens. METHODS: We produced a Nanoluciferase™ tagged Ezrin (NLuc-Ezrin). NLuc-Ezrin was then used as antigen in LIPS to test for Ezrin autoantibodies patients affected by PDAC (n= 40), other pancreatic diseases (OPD, n= 50), and healthy controls (n= 60). RESULTS: Overall, binding in liquid phase to Ezrin by serum antibodies was rare and low titer. Furthermore, we did not find statistically significant differences in the prevalence of Ezrin autoantibodies between patients affected by either PDAC or OPD compared to control. CONCLUSIONS: Our results do not confirm the usefulness of Ezrin autoAbs as biomarker of PDAC.