title: Biomarkers for atopic dermatitis: a systematic review and meta-analysis.
abstract: OBJECTIVE
  A large number of studies investigating the correlation between severity of atopic dermatitis and various biomarkers have been published over the past decades. The aim of this review was to identify, evaluate and synthesize the evidence examining the correlation of biomarkers with disease severity in atopic dermatitis patients, something that has not been performed previously.
  
  
  RESULTS
  Three electronic databases were systematically searched and relevant studies were selected for inclusion. A total of 222 articles, reporting on 115 different biomarkers in 30 063 patients, were critically appraised. Studies were divided into two main groups. The first group consisted of longitudinal randomized controlled trials and cohort studies, which reported measurements at multiple time points. The second contained cross-sectional studies that reported only one measurement per patient. Out of 222 articles, 108 articles reported sufficient data for meta-analysis. Only four biomarkers were eligible for meta-analysis in the longitudinal group, and nine in the cross-sectional group.
  
  
  CONCLUSIONS
  Serum thymus and activation-regulated chemokine (TARC) was found to be the most reliable biomarker studied, showing pooled correlation coefficients of 0.60 (95% CI 0.48-0.70) and 0.64 (95% CI 0.57-0.70) in longitudinal and cross-sectional studies, respectively. Additional biomarkers that could prove useful but require additional research include serum cutaneous T-cell attracting chemokine (CTACK), sE-selectin, macrophage-derived chemokine (MDC), lactate dehydrogenase (LDH) and interleukin (IL)-18.
authors.affiliation: aDepartment of Dermatology and Allergy, University Medical Center Utrecht, Utrecht, The Netherlands bDepartment of Dermatology, Venereology and Allergy, University Hospital Schleswig-Holstein, Campus Kiel, Germany cDepartment of Radiology, University Medical Center Utrecht, Utrecht, The Netherlands dDepartment of Paediatric Dermatology, St John's Institute of Dermatology, Guy's and St Thomas' Hospitals NHS Foundation Trust and King's College, London, UK.
authors.forename: Judith
authors.initials: J
authors.lastname: Thijs
authors.forename: Todor
authors.initials: T
authors.lastname: Krastev
authors.forename: Stephan
authors.initials: S
authors.lastname: Weidinger
authors.forename: Constantinus F
authors.initials: CF
authors.lastname: Buckens
authors.forename: Marjolein
authors.initials: M
authors.lastname: de Bruin-Weller
authors.forename: Carla
authors.initials: C
authors.lastname: Bruijnzeel-Koomen
authors.forename: Carsten
authors.initials: C
authors.lastname: Flohr
authors.forename: DirkJan
authors.initials: D
authors.lastname: Hijnen
mesh_terms: D015415:Biomarkers / Q000097:blood*; D054414:Chemokine CCL17 / Q000097:blood; D054422:Chemokine CCL22 / Q000097:blood; D054425:Chemokine CCL27 / Q000097:blood; D003876:Dermatitis, Atopic / Q000175:diagnosis*; D019040:E-Selectin / Q000097:blood; D006801:Humans; D020382:Interleukin-18 / Q000097:blood; D007770:L-Lactate Dehydrogenase / Q000097:blood
chemical_list: D015415:Biomarkers; D054414:Chemokine CCL17; D054422:Chemokine CCL22; D054425:Chemokine CCL27; D019040:E-Selectin; D020382:Interleukin-18; D007770:L-Lactate Dehydrogenase