title: Serum biomarkers in patients with relapsing eosinophilic granulomatosis with polyangiitis (Churg-Strauss).
abstract: BACKGROUND
  Previous studies suggest a role for eotaxin-3, TARC/CCL17 and IgG4 in newly-diagnosed patients with eosinophilic granulomatosis with polyangiitis (EGPA, Churg-Strauss) with highly active disease. The role of these biomarkers in relapsing disease is unclear.
  
  
  METHODS
  Serum levels of TARC/CCL17, eotaxin-3, IgG4, and IgG4/IgG ratio were determined in serum samples from a longitudinal cohort of patients with EGPA (105 visits of 25 patients). Epidemiological, clinical and laboratory data were available for all visits.
  
  
  RESULTS
  At the first visit, 80% of patients were using glucocorticoids and 68% additional immunosuppressive drugs. Disease flares were seen at 18 visits. The median BVAS and BVAS/WG scores at time of relapse were 4 and 2, respectively. None of the biomarkers tested were useful to discriminate between active disease and remission. Patients treated with prednisone had lower eotaxin-3 and eosinophil levels compared to patients not taking glucocorticoids irrespective of disease activity. Use of immunosuppressive agents was not associated with biomarker levels.
  
  
  CONCLUSIONS
  Serum levels of TARC/CCL17, eotaxin-3, IgG4, and IgG4/IgG ratio do not clearly differentiate active and inactive disease in established EGPA. Defining biomarkers in EGPA remains a challenge especially during times of glucocorticoid use.
authors: Department of Rheumatology and Immunology, Medical University of Graz, Graz, Austria.
authors: Christian
authors: C
authors: Dejaco
authors: 1st Medical Department and Ludwig Boltzmann Institute of Osteology, Hanusch Hospital, Vienna, Austria.
authors: Bastian
authors: B
authors: Oppl
authors: Section of Rheumatology, Boston University School of Medicine, Boston, MA, United States of America.
authors: Paul
authors: P
authors: Monach
authors: Department of Pediatrics, University of South Florida College of Medicine, Tampa, FL, United States of America.
authors: David
authors: D
authors: Cuthbertson
authors: Division of Rheumatology, Mount Sinai Hospital, Toronto, ON, Canada.
authors: Simon
authors: S
authors: Carette
authors: Department of Rheumatology, Cleveland Clinic, Cleveland, OH, United States of America.
authors: Gary
authors: G
authors: Hoffman
authors: Division of Rheumatology, McMaster University, Hamilton, ON, Canada.
authors: Nader
authors: N
authors: Khalidi
authors: Division of Rheumatology, University of Utah, Salt Lake City, UT, United States of America; George E. Wahlen Department of Veterans Affairs Medical Center, Salt Lake City, UT, United States of America.
authors: Curry
authors: C
authors: Koening
authors: Department of Rheumatology, Cleveland Clinic, Cleveland, OH, United States of America.
authors: Carol
authors: C
authors: Langford
authors: Division of Rheumatology, University of Pittsburgh, Pittsburgh, PA, United States of America.
authors: Kathleen
authors: K
authors: McKinnon-Maksimowicz
authors: Division of Rheumatology, Johns Hopkins University, Baltimore, MD, United States of America.
authors: Philip
authors: P
authors: Seo
authors: Division of Pulmonary and Critical Care Medicine, Mayo Clinic College of Medicine, Rochester, MN, United States of America.
authors: Ulrich
authors: U
authors: Specks
authors: Division of Rheumatology, Mayo Clinic College of Medicine, Rochester, MN, United States of America.
authors: Steven
authors: S
authors: Ytterberg
authors: Division of Rheumatology, University of Pennsylvania, Philadelphia, PA, United States of America.
authors: Peter A
authors: PA
authors: Merkel
authors: 1st Medical Department and Ludwig Boltzmann Institute of Osteology, Hanusch Hospital, Vienna, Austria; Department of Internal Medicine 3, University of Erlangen-Nuremberg, Erlangen, Germany.
authors: Jochen
authors: J
authors: Zwerina
mesh_terms: D000328:Adult; D015415:Biomarkers; D054414:Chemokine CCL17 / Q000097:blood; D000075906:Chemokine CCL26; D019742:Chemokines, CC / Q000097:blood; D015267:Churg-Strauss Syndrome / Q000097:blood* / Q000188:drug therapy / Q000276:immunology / Q000473:pathology; D004804:Eosinophils; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012008:Recurrence
chemical_list: D015415:Biomarkers; C120429:CCL26 protein, human; D054414:Chemokine CCL17; D000075906:Chemokine CCL26; D019742:Chemokines, CC; D007074:Immunoglobulin G; D007166:Immunosuppressive Agents