title: Neuroimmunomodulatory alterations in non-lesional peritoneum close to peritoneal endometriosis.
abstract: OBJECTIVE
  An imbalance in the ratio of sensory to sympathetic nerve fibre (NF) density in peritoneal endometriotic lesions (pEL) has recently been demonstrated and leads to the assumption that this preponderance of the sensory pro-inflammatory milieu is a major cause of pain in endometriosis. Therefore, the density of sensory and sympathetic NFs was determined in distal unaffected peritoneum of endometriosis patients to be able to detect possible alterations in unaffected peritoneum.
  
  
  METHODS
  In serial pEL sections (n = 40), lesional and matching unaffected peritoneum as well as healthy peritoneum (HP) from patients without endometriosis (n = 15) were immunohistochemically analysed to identify protein gene product 9.5-, substance P- and tyrosine hydroxylase-positive NFs (intact, sensory and sympathetic NFs, respectively). In addition, the amount of immune cell infiltrates and the expression of nerve growth factor (NGF) and interleukin (IL)-1β in nerves of peritoneal endometriotic specimens were compared to those in the HP.
  
  
  RESULTS
  The overall NF density in the non-lesional, unaffected peritoneum of endometriosis patients is significantly reduced in comparison to both HP and pEL, while sensory NFs remain the same; the sympathetic NF density is significantly decreased compared to HP, but is still higher than the density close to the pEL. Immune cell infiltrates as well as NGF and IL-1β expression in nerves is significantly elevated in distal unaffected peritoneum in comparison to HP.
  
  
  CONCLUSIONS
  The altered NF density in the non-lesional, unaffected peritoneum of endometriosis patients suggests new aspects in the understanding of the development of endometriosis and pain management in endometriosis.
authors.affiliation: Department of Gynecology, Endometriosis Research Centre, Charité, Berlin, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Arnold
authors.forename: Giuseppe Filiberto
authors.initials: GF
authors.lastname: Vercellino
authors.forename: Vito
authors.initials: V
authors.lastname: Chiantera
authors.forename: Achim
authors.initials: A
authors.lastname: Schneider
authors.forename: Sylvia
authors.initials: S
authors.lastname: Mechsner
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Barcena de Arellano
mesh_terms: D000293:Adolescent; D000320:Adrenergic Fibers / Q000473:pathology; D000328:Adult; D004715:Endometriosis / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D020932:Nerve Growth Factor / Q000378:metabolism; D010532:Peritoneal Diseases / Q000276:immunology / Q000378:metabolism / Q000473:pathology*; D010537:Peritoneum / Q000276:immunology / Q000294:innervation* / Q000473:pathology; D013373:Substance P / Q000378:metabolism; D055815:Young Adult
chemical_list: D013373:Substance P; D020932:Nerve Growth Factor