title: Characterization of asthma endotypes: implications for therapy.
abstract: To describe the concept of precision medicine in treating severe asthma and the utility of relevant biomarkers.
  
  
  
  PubMed was searched for published articles on human clinical trials using biologics for T-helper type 2 cell (TH2)-low and TH2-high asthma.
  
  
  
  Studies were selected if they were double-masked, randomized, placebo-controlled trials published in peer-reviewed journals and relevant to the topic.
  
  
  
  Multiple immune response modifiers have been evaluated in TH2-high asthma geared at blocking interleukin (IL)-5, IL-13, immunoglobulin E, prostaglandin D2, and other pathways. Currently, 3 immune response modifiers approved by the Food and Drug Administration are available for treating severe TH2-high asthma (1 anti-immunoglobulin E and 2 anti-IL-5 monoclonal antibodies) and other TH2-high therapies are in various stages of clinical development. Thus far, many of the TH2-high therapies have shown better efficacy when certain biomarkers are elevated, especially blood eosinophils. The TH2-low endotype does not have any readily available point-of-care biomarkers, so TH2-low asthma is often diagnosed based on a lack of TH2-high biomarkers. These patients tend to have greater resistance to steroids and the development of therapies has lagged behind that for TH2-high asthma.
  
  
  
  Two major endotypes for asthma have been described, TH2-high, manifested by increased eosinophils in the sputum and airways of patients, and TH2-low, with increased neutrophils or a pauci-granulocytic profile. Using these classifications and specific biomarkers has led to promising new therapeutics, especially for TH2-high asthma.
authors: Division of Allergy and Immunology, Creighton University, Omaha, Nebraska.
authors: Jeffrey R
authors: JR
authors: Stokes
authors: Division of Allergy and Immunology, University of South Florida, Morsani College of Medicine, Tampa, Florida. Electronic address: tbcasale@creighton.edu.
authors: Thomas B
authors: TB
authors: Casale
mesh_terms: D018927:Anti-Asthmatic Agents / Q000494:pharmacology / Q000627:therapeutic use; D001249:Asthma / Q000097:blood / Q000188:drug therapy* / Q000276:immunology* / Q000378:metabolism; D001688:Biological Products / Q000494:pharmacology / Q000627:therapeutic use; D015415:Biomarkers; D002986:Clinical Trials as Topic; D016207:Cytokines / Q000378:metabolism; D006801:Humans; D018836:Inflammation Mediators / Q000378:metabolism; D018655:Lymphocyte Count; D058990:Molecular Targeted Therapy; D057285:Precision Medicine; D015398:Signal Transduction / Q000187:drug effects; D018418:Th2 Cells / Q000276:immunology* / Q000378:metabolism
chemical_list: D018927:Anti-Asthmatic Agents; D001688:Biological Products; D015415:Biomarkers; D016207:Cytokines; D018836:Inflammation Mediators