Triosephosphate isomerase, carbonic anhydrase, and creatinine kinase-brain isoform are possible antigen targets in patients with achalasia.

Background: Idiopathic achalasia is an uncommon esophageal motor disorder. The disease involves interaction between inflammatory and autoimmune responses. However, the antigens related to the disease are still unknown.
Aim: To identify the possible antigen targets in muscle biopsies from lower esophageal sphincter (LES) of achalasia patients.
Methods: Esophageal biopsies of patients with type I and type II achalasia and esophagogastric junction outflow obstruction (EGJOO) were analyzed. Lower esophageal sphincter muscle biopsy from a Healthy organ Donor (HD) was included as control for two-dimensional gel electrophoresis. Immunoblotting of muscle from LES lysate with sera of type I, type II achalasia, or type III achalasia, sera of EGJOO and sera of healthy subjects (HS) was performed. The target proteins of the serum were identified by mass spectrometry Matrix-assited laser desorption/ionization time-of-flight (MALDI-TOF).
Key Results: The proteomic map of muscle from LES tissue lysates of type I, and type II achalasia, EGJOO, and HD were analyzed and divided into three important regions. We found a difference in the concentration of certain spots. Further, we observed the serum reactivity of type I achalasia and type II achalasia against 45 and 25 kDa bands of type I achalasia tissue. Serum of type III achalasia and EGJOO mainly recognized 25 kDa band. Bands correspond to triosephosphate isomerase (TPI) (25 kDa), carbonic anhydrase (CA) (25 kDa) and creatinine kinase-brain (CKB) isoform (45 kDa).
Conclusions and Inferences: We identify three antigen targets, TPI, CA, and CKB isoform, which are recognized by sera from patients with achalasia.
(© 2020 John Wiley & Sons Ltd.)