title: Periostin, a novel biomarker of TH2-driven asthma.
abstract: OBJECTIVE
  Asthma is a heterogeneous disease with multiple, overlapping phenotypes. Biomarkers are currently being investigated to better characterize the disease phenotypes and to identify the responders to specific targeted therapies. This review focuses on the emerging data surrounding the use of one such biomarker for T helper 2 (TH2)-driven asthma: periostin.
  
  
  RESULTS
  Periostin is an extracellular matrix protein that is induced by interleukin (IL)-4 and IL-13 in airway epithelial cells and lung fibroblasts. It has proven to be an important biomarker of TH2-associated airway inflammation and a potential predictor of airway eosinophilia. It has also been shown to predict response to treatment with inhaled corticosteroids in patients with these characteristics. Furthermore, recent asthma clinical trials have established that serum periostin may have value in predicting the response to targeted therapy with biologic agents such as lebrikizumab and omalizumab.
  
  
  CONCLUSIONS
  Emerging data suggest a role for periostin in refining asthma phenotypes and predicting the response to targeted therapy. Although early data are promising, further investigations are needed to confirm these findings and to identify other clinical applications in which periostin may be valuable.
authors.affiliation: Section of Pulmonary, Critical Care and Sleep Medicine, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Amit D
authors.initials: AD
authors.lastname: Parulekar
authors.forename: Mustafa A
authors.initials: MA
authors.lastname: Atik
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Hanania
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D001249:Asthma / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D001688:Biological Products / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D006801:Humans; D010641:Phenotype; D011237:Predictive Value of Tests; D018418:Th2 Cells / Q000473:pathology*; D016896:Treatment Outcome
chemical_list: D000305:Adrenal Cortex Hormones; D001688:Biological Products; D015415:Biomarkers; D015815:Cell Adhesion Molecules; C512835:POSTN protein, human