title: Plasma Levels of Matrix Metalloproteinase-9 in Children With Chronic Spontaneous Urticaria.
abstract: OBJECTIVE
  Chronic spontaneous urticaria (CSU) is a disease that is primarily seen in adults and is comparatively rare in children. Consequently, only a few studies have focused on the pathogenesis of the disease in children. This study investigated the possible role of metalloproteinase-9 (MMP-9) in the pathogenesis of CSU in children.
  
  
  METHODS
  The study group was composed of 54 children with CSU; 34 healthy children comprised the control group. The demographic and clinical features of the study group were extensively evaluated, and laboratory assessments were also performed. An enzyme-linked immunosorbent assay was used to evaluate levels of plasma MMP-9. Disease activity was quantified using the urticaria activity score (UAS).
  
  
  RESULTS
  The median value of plasma MMP-9 was 108.9 ng/mL (interquartile range, 93.3-124.1) in the CSU group and 87.8 ng/mL (69.4-103.0) in the control group. The difference between the 2 groups was statistically significant (P<0.001). Also, MMP-9 levels showed a significant positive correlation with UAS (rho=0.57, P<0.001). Twenty-six percent of patients had positive autologous serum skin test (ASST) results. Neither UAS nor plasma MMP-9 levels were significantly different between ASST-positive and -negative patients (P>0.05).
  
  
  CONCLUSIONS
  Plasma MMP-9 levels were elevated in children with CSU and were positively correlated with disease activity. MMP-9 may be both a good biomarker of disease activity and a potential therapeutic target in CSU.
authors: Department of Pediatric Allergy and Immunology, Bezmialem Vakif University Medical Faculty, Istanbul, Turkey. drfatihdilek@yahoo.com.
authors: Fatih
authors: F
authors: Dilek
authors: Department of Pediatric Allergy, Istanbul University Istanbul Medical Faculty, Istanbul, Turkey.
authors: Deniz
authors: D
authors: Ozceker
authors: Department of Pediatric Allergy and Immunology, Bezmialem Vakif University Medical Faculty, Istanbul, Turkey.
authors: Emin
authors: E
authors: Ozkaya
authors: Department of Pediatric Allergy, Istanbul University Istanbul Medical Faculty, Istanbul, Turkey.
authors: Zeynep
authors: Z
authors: Tamay
authors: Department of Pediatric Allergy and Immunology, Bezmialem Vakif University Medical Faculty, Istanbul, Turkey.
authors: Mebrure
authors: M
authors: Yazici
authors: Department of Clinical Biochemistry, Bezmialem Vakif University Medical Faculty, Istanbul, Turkey.
authors: Siddika
authors: S
authors: Kesgin
authors: Department of Clinical Biochemistry, Bezmialem Vakif University Medical Faculty, Istanbul, Turkey.
authors: Abdurrahim
authors: A
authors: Kocyigit
authors: Department of Pediatrics, Istanbul Bilim University, Istanbul, Turkey.
authors: Nermin
authors: N
authors: Guler
keywords: Chronic spontaneous urticaria; MMP-9; children; disease severity