title: High post surgical opioid requirements in Crohn's disease are not due to a general change in pain sensitivity.
abstract: Crohn's disease (CD) is a painful inflammatory bowel disease with complex multigenic inheritance. Suggested on the basis of a few isolated reports CD patients require significantly higher post operative opioid doses than patients undergoing comparable severe abdominal surgery. Crohn's disease therefore may be a suitable model for the identification of novel pain susceptibility genes. In order to confirm this observation and to elucidate the underlying molecular mechanisms, we investigated if higher opioid needs of CD patients are due to a general change in pain sensitivity. Quantitative sensory testing (QST) was applied to a subgroup of patients and polymorphisms in the mu-opioid receptor (OPRM1) and catechol-O-methyltransferase (COMT) were investigated. Significantly increased post operative opioid requirements in CD patients were confirmed and QST assessment demonstrates that CD patients do not display increased pain sensitivity in terms of lowered thresholds to thermal and mechanical stimuli. The data also suggest that common variants in OPRM1 and specific 'high pain sensitivity'COMT haplotypes may not be the cause of high opioid needs. The results indicate that a more complex pathway is involved in the greater post operative opioid demand in CD. Therefore the presence of other, as yet unknown, genes could modulate opioid requirements in CD patients.
authors.affiliation: Institute of Human Genetics, University Erlangen-Nuremberg, Schwabachanlage 10, 91054 Erlangen, Germany. khuehne@humgenet.uni-erlangen.de
authors.forename: Kathrin
authors.initials: K
authors.lastname: Huehne
authors.forename: Stefan
authors.initials: S
authors.lastname: Leis
authors.forename: Tino
authors.initials: T
authors.lastname: Muenster
authors.forename: Andreas
authors.initials: A
authors.lastname: Wehrfritz
authors.forename: Stefanie
authors.initials: S
authors.lastname: Winter
authors.forename: Christian
authors.initials: C
authors.lastname: Maihöfner
authors.forename: Thomas
authors.initials: T
authors.lastname: Foertsch
authors.forename: Roland
authors.initials: R
authors.lastname: Croner
authors.forename: André
authors.initials: A
authors.lastname: Reis
authors.forename: Andreas
authors.initials: A
authors.lastname: Winterpacht
authors.forename: Bernd
authors.initials: B
authors.lastname: Rautenstrauss
mesh_terms: D000328:Adult; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000627:therapeutic use*; D002394:Catechol O-Methyltransferase / Q000235:genetics; D003424:Crohn Disease / Q000601:surgery*; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D005260:Female; D005838:Genotype; D006239:Haplotypes; D006801:Humans; D008297:Male; D008875:Middle Aged; D053473:Nod2 Signaling Adaptor Protein; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy* / Q000523:psychology; D011446:Prospective Studies; D017450:Receptors, Opioid, mu / Q000235:genetics; D012189:Retrospective Studies
chemical_list: D000701:Analgesics, Opioid; D053473:Nod2 Signaling Adaptor Protein; C485764:OPRM1 protein, human; D017450:Receptors, Opioid, mu; D004247:DNA; D002394:Catechol O-Methyltransferase