Phagocyte-specific S100 proteins and high-sensitivity C reactive protein as biomarkers for a risk-adapted treatment to maintain remission in juvenile idiopathic arthritis: a comparative study

Ann Rheum Dis. 2012 Dec;71(12):1991-7. doi: 10.1136/annrheumdis-2012-201329. Epub 2012 Jun 11.

Abstract

Objectives: Juvenile idiopathic arthritis (JIA) is a chronic inflammatory joint disease affecting children. Even if remission is successfully induced, about half of the patients experience a relapse after stopping anti-inflammatory therapy. The present study investigated whether patients with JIA at risk of relapse can be identified by biomarkers even if clinical signs of disease activity are absent.

Methods: Patients fulfilling the criteria of inactive disease on medication were included at the time when all medication was withdrawn. The phagocyte activation markers S100A12 and myeloid-related proteins 8/14 (MRP8/14) were compared as well as the acute phase reactant high-sensitivity C reactive protein (hsCRP) as predictive biomarkers for the risk of a flare within a time frame of 6 months.

Results: 35 of 188 enrolled patients experienced a flare within 6 months. Clinical or standard laboratory parameters could not differentiate between patients at risk of relapse and those not at risk. S100A12 and MRP8/14 levels were significantly higher in patients who subsequently developed flares than in patients with stable remission. The best single biomarker for the prediction of flare was S100A12 (HR 2.81). The predictive performance may be improved if a combination with hsCRP is used.

Conclusions: Subclinical disease activity may result in unstable remission (ie, a status of clinical but not immunological remission). Biomarkers such as S100A12 and MRP8/14 inform about the activation status of innate immunity at the molecular level and thereby identify patients with unstable remission and an increased risk of relapse.

Publication types

  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / metabolism
  • Antirheumatic Agents / therapeutic use*
  • Arthritis, Juvenile / drug therapy*
  • Arthritis, Juvenile / epidemiology
  • Arthritis, Juvenile / metabolism*
  • Biomarkers / metabolism
  • C-Reactive Protein / metabolism*
  • Calgranulin A / metabolism
  • Calgranulin B / metabolism
  • Child
  • Drug Monitoring / methods*
  • Female
  • Humans
  • Kaplan-Meier Estimate
  • Leukocyte L1 Antigen Complex / metabolism
  • Male
  • Phagocytes / metabolism
  • Recurrence
  • Remission Induction
  • Risk Factors
  • S100 Proteins / metabolism*
  • S100A12 Protein
  • Sensitivity and Specificity

Substances

  • ABCC11 protein, human
  • ATP-Binding Cassette Transporters
  • Antirheumatic Agents
  • Biomarkers
  • Calgranulin A
  • Calgranulin B
  • Leukocyte L1 Antigen Complex
  • S100 Proteins
  • S100A12 Protein
  • S100A12 protein, human
  • C-Reactive Protein