title: Elevated platelet activation in patients with chronic urticaria: a comparison between aspirin-intolerant and aspirin-tolerant groups.
abstract: BACKGROUND
  Platelets are actively involved in immune inflammatory processes that release inflammatory mediators. Platelet activation has been reported in various inflammatory diseases; however, few studies have described platelet involvement in chronic urticaria (CU).
  
  
  OBJECTIVE
  To investigate platelet-activation markers, namely P2Y12 receptor and P-selectin expression, and soluble P-selectin level in patients with aspirin-intolerant CU (AICU) and aspirin-tolerant CU (ATCU).
  
  
  METHODS
  Forty-eight patients with CU and 25 normal controls were enrolled in this study. Aspirin intolerance in patients with CU was confirmed by an oral provocation test. P2Y12 and P-selectin expressions on platelets were measured using flow cytometry; soluble P-selectin level in plasma was measured by enzyme-linked immunosorbent assay. To study the functional effects of aspirin, platelets were treated with aspirin (2 mmol/L) and the expressions of P2Y12 and P-selectin were compared between the AICU and ATCU groups.
  
  
  RESULTS
  The expression of P2Y12 was significantly higher in patients with CU compared with controls, whereas no significant difference was noted in the expression of P-selectin level. The levels were not significantly different according to urticaria symptom score, symptom control status, and aspirin intolerance. Soluble P-selectin level was significantly higher in the AICU group than in the ATCU group compared with controls. Aspirin did not significantly suppress P2Y12 and P-selectin expressions on platelets in the AICU group, whereas significant suppression was noted in the ATCU group.
  
  
  CONCLUSIONS
  These findings suggest that increased platelet activation contributes to skin inflammation in patients with AICU and those with ATCU. The functional difference of platelets in response to aspirin may contribute to persistent skin inflammation in patients with AICU.
authors.affiliation: Department of Biomedical Sciences, Graduate School of Ajou University, Suwon, Korea; Department of Allergy and Clinical Immunology, Ajou University, School of Medicine, Suwon, South Korea.
authors.forename: Sailesh
authors.initials: S
authors.lastname: Palikhe
authors.affiliation: Pulmonary Research Group, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Nami Shrestha
authors.initials: NS
authors.lastname: Palikhe
authors.affiliation: Department of Allergy and Clinical Immunology, Ajou University, School of Medicine, Suwon, South Korea.
authors.forename: Seung-Hyun
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Biomedical Sciences, Graduate School of Ajou University, Suwon, Korea.
authors.forename: Hye-Soo
authors.initials: HS
authors.lastname: Yoo
authors.affiliation: Department of Biomedical Sciences, Graduate School of Ajou University, Suwon, Korea.
authors.forename: Yoo Seob
authors.initials: YS
authors.lastname: Shin
authors.affiliation: Department of Biomedical Sciences, Graduate School of Ajou University, Suwon, Korea; Department of Allergy and Clinical Immunology, Ajou University, School of Medicine, Suwon, South Korea. Electronic address: hspark@ajou.ac.kr.
authors.forename: Hae-Sim
authors.initials: HS
authors.lastname: Park
mesh_terms: D000328:Adult; D001241:Aspirin / Q000276:immunology; D015415:Biomarkers / Q000378:metabolism; D001792:Blood Platelets / Q000276:immunology / Q000378:metabolism; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000378:metabolism; D015539:Platelet Activation / Q000187:drug effects / Q000276:immunology*; D058925:Receptors, Purinergic P2Y12 / Q000378:metabolism; D014581:Urticaria / Q000097:blood / Q000276:immunology* / Q000378:metabolism; D055815:Young Adult
chemical_list: D015415:Biomarkers; D019007:P-Selectin; D058925:Receptors, Purinergic P2Y12; D001241:Aspirin