title: Variations in inflammation and nerve fiber loss reflect different subsets of achalasia patients.
abstract: BACKGROUND
  Achalasia is a debilitating motility disorder with an unknown etiology. Past research has demonstrated a spectrum of histological findings. The objective of this study was to further characterize the histopathology of achalasia, with attention to subsets of findings that may exist, possibly reflecting different pathogeneses.
  
  
  METHODS
  Lower esophageal muscle was obtained during surgery for achalasia (n = 12) or cancer (n = 9). Immunohistochemistry was performed to identify various inflammatory cells and nerve fibers, and grading was done by an expert pathologist. Clinical data were taken from medical records.
  
  
  RESULTS
  There were two subsets of achalasia specimens with different histological findings. Group A (7/12; 58%) had an inflammatory infiltrate in the myenteric plexus consisting primarily of T-lymphocytes. Group B (5/12; 42%) had no such infiltrate and had less myenteric plexus macrophages versus Group A (P = 0.03). The loss of nerve fibers was most evident in the muscularis propria in achalasia as compared to controls (P = 0.01), and this loss was more striking in Group B versus A (P = 0.04). The mean duration of symptoms was 16.6 (A) versus 6.4 years (B) (P = NS).
  
  
  CONCLUSIONS
  Two subsets of achalasia patients exist with different histological findings. Group A had T-cell-rich inflammation present with associated macrophages. Group B, with no inflammation, had greater loss of nerve fibers in the muscularis propria versus Group A, and therefore, may represent more aggressive disease with shorter duration of symptoms. These results suggest that various pathogeneses of achalasia may exist that share a common pathway of aganglionosis.
authors.affiliation: Department of Surgery, Heart, Lung, and Esophageal Surgery Institute, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA. schuchertmj@upmc.edu
authors.forename: Arman
authors.initials: A
authors.lastname: Kilic
authors.forename: Alyssa M
authors.initials: AM
authors.lastname: Krasinskas
authors.forename: Scott R
authors.initials: SR
authors.lastname: Owens
authors.forename: James D
authors.initials: JD
authors.lastname: Luketich
authors.forename: Rodney J
authors.initials: RJ
authors.lastname: Landreneau
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Schuchert
mesh_terms: D000328:Adult; D000368:Aged; D004931:Esophageal Achalasia / Q000145:classification / Q000209:etiology / Q000473:pathology*; D004947:Esophagus / Q000294:innervation* / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000473:pathology*; D008264:Macrophages / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009197:Myenteric Plexus / Q000502:physiology; D009410:Nerve Degeneration / Q000473:pathology; D009412:Nerve Fibers / Q000473:pathology*