title: Substance P and intensity of pruritus in hemodialysis and peritoneal dialysis patients.
abstract: BACKGROUND
  Uremic pruritus is a common complication in patients undergoing dialysis. The pathophysiological mechanisms of pruritus in patients with end-stage renal disease remain unknown. Neuropeptides, including substance P, are postulated to play an important role in the pathogenesis of pruritus. The aim of this study was to evaluate the role of substance P in uremic pruritus in patients on hemodialysis and peritoneal dialysis.
  
  
  METHODS
  We included 197 patients with end-stage renal disease: 54 on continuous ambulatory peritoneal dialysis and 143 on hemodialysis. Substance P, calcium, phosphorus, iron, ferritin, CRP, albumin, hemoglobin, Ca×P product, and iPTH level were determined in all participants. The correlation between these parameters and self-reported itching was evaluated in patients on hemodialysis in comparison with peritoneal dialysis patients.
  
  
  RESULTS
  The incidence of itching was similar in hemodialysis and peritoneal dialysis patients. No differences in substance P level between the 2 groups were found. There was no correlation between substance P level and the incidence or intensity of pruritus in dialyzed patients.
  
  
  CONCLUSIONS
  This study demonstrates that substance P does not play any important role in pruritus in hemodialysed and peritoneal dialyzed patients. However, further studies are necessary to assess the exact role of neuropeptides in uremic pruritus.
authors.affiliation: Department of Internal Medicine, Diabetology and Nephrology, Zabrze, Medical University of Silesia, Katowice, Poland.
authors.forename: Mirosław
authors.initials: M
authors.lastname: Snit
authors.forename: Radosław
authors.initials: R
authors.lastname: Gawlik
authors.forename: Beata
authors.initials: B
authors.lastname: Łącka-Gaździk
authors.forename: Roman
authors.initials: R
authors.lastname: Kuźniewicz
authors.forename: Marek
authors.initials: M
authors.lastname: Dwornicki
authors.forename: Aleksander
authors.initials: A
authors.lastname: Owczarek
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Walaszczyk
authors.forename: Piotr
authors.initials: P
authors.lastname: Grabiec
authors.forename: Władysław
authors.initials: W
authors.lastname: Grzeszczak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism; D002118:Calcium / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005293:Ferritins / Q000097:blood; D006801:Humans; D007501:Iron / Q000097:blood; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D009391:Nephelometry and Turbidimetry; D010281:Parathyroid Hormone / Q000097:blood; D010530:Peritoneal Dialysis / Q000009:adverse effects*; D010758:Phosphorus / Q000097:blood; D011537:Pruritus / Q000209:etiology* / Q000473:pathology*; D006435:Renal Dialysis / Q000009:adverse effects*; D018709:Statistics, Nonparametric; D013373:Substance P / Q000378:metabolism*
chemical_list: D010281:Parathyroid Hormone; D010758:Phosphorus; D013373:Substance P; D002097:C-Reactive Protein; D005293:Ferritins; D007501:Iron; D002118:Calcium