title: Usefulness of mean corpuscular volume as a surrogate marker for monitoring thiopurine treatment in inflammatory bowel disease.
abstract: BACKGROUND
  Thiopurines are commonly used drugs in inflammatory bowel disease. Intracellular levels of thiopurine metabolites [i.e. 6-thioguaninenucleotides (6-TGN)] are associated with efficacy and toxicity. Because 6-TGN measurement is not globally available, the mean corpuscular volume (MCV) has been proposed as a surrogate marker for monitoring thiopurine therapy.
  
  
  OBJECTIVE
  To analyze the relationship between MCV and efficacy of thiopurines, defined as either response to therapy or 6-TGN levels.
  
  
  METHODS
  A systematic search on PubMed was performed.
  
  
  RESULTS
  Fifteen studies were included. In six studies, a positive association was found between ΔMCV and 6-TGN. In four studies, it was suggested that ΔMCV can be used to predict clinical remission. In five articles, no association was found.
  
  
  CONCLUSIONS
  In the majority of articles, it was reported that ΔMCV is useful in guiding intracellular metabolite levels. However, there is insufficient evidence showing that ΔMCV can predict clinical remission.
authors.affiliation: aDepartment of Gastroenterology, Academic Medical Center bDepartment of Gastroenterology and Hepatology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Romein W G
authors.initials: RW
authors.lastname: Dujardin
authors.forename: Berrie
authors.initials: B
authors.lastname: Meijer
authors.forename: Nanne K H
authors.initials: NK
authors.lastname: de Boer
authors.forename: Geert R
authors.initials: GR
authors.lastname: D'Haens
authors.forename: Mark
authors.initials: M
authors.lastname: Löwenberg
mesh_terms: D000893:Anti-Inflammatory Agents / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D016903:Drug Monitoring / Q000379:methods*; D004909:Erythrocyte Indices; D005765:Gastrointestinal Agents / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000097:blood / Q000175:diagnosis / Q000188:drug therapy*; D011237:Predictive Value of Tests; D011687:Purines / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D013866:Thioguanine / Q000097:blood; D016896:Treatment Outcome
chemical_list: D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D005765:Gastrointestinal Agents; D011687:Purines; D013866:Thioguanine