Esophagogastric junction outflow obstruction: Characterization of a new entity? Clinical, manometric, and neuroimmunological description.

Objective To determine the differences between clinical, manometric, and neuroimmunological profile of esophagogastric junction outflow obstruction (EGJOO) and achalasia patients. Methods Seven EGJOO and 27 achalasia patients were enrolled in a blind cross-sectional study. Peripheral blood (PB) of 10 healthy donors and 10 lower esophageal sphincter (LES) muscle biopsies from organ transplant donors were included as controls. The presence of ganglion cells, cells of Cajal, Th22/Th7/Th2/Th1/Tregs/Bregs/pDCregs in tissue, and PB was assessed by immunohistochemistry and flow cytometry. Serum concentration of IL-22/IL-17A/IL-17F/IL-4/IFN-gamma/IL-1 beta/IL-6/IL-23/IL-33/TNF-alpha/IL-10 was determined using bioplex plates. ANAs and antineuronal antibodies were evaluated by immunofluorescence and Western blot. Key Results EGJOO and achalasia patients had lower ganglion cells and cells of Cajal percentage vs. controls, while fibrosis was present only in achalasia patients. EGJOO and controls had lower cell percentage of Th22/Th17/Th2 vs. achalasia. EGJOO tissue had lower Th1/Treg cell number vs. achalasia, but higher levels vs. control group. Bregs and pDCregs percentage was higher in EGJOO vs. control group. Percentage of PB subpopulations in EGJOO was not significantly different from control group. Serum cytokine levels were higher for IL-1 beta/IL-6/TNF-alpha, while IL-17A levels were lower in EGJOO vs. achalasia and control group. EGJOO group was negative for ANAs, while in achalasia group, 54% were positive. GAD65 and PNMa/Ta2 antibodies were present in achalasia, whereas Yo and recoverin were positive in EGJOO group. Conclusions and Inferences Although EGJOO shares some clinical characteristics with achalasia, the neuroimmunological profile is completely different, suggesting that EGJOO might be a different entity.