title: Prevalence and pathogenesis of anemia in inflammatory bowel disease. Influence of anti-tumor necrosis factor-alpha treatment.
abstract: BACKGROUND
  Anemia is a common complication of inflammatory bowel disease, but its epidemiology may be changing due to earlier diagnosis and improved treatments. We investigated the prevalence and pathogenesis of anemia in patients with inflammatory bowel disease.
  
  
  METHODS
  In a cross-sectional study 263 out-patients with inflammatory bowel disease (165 with Crohn's disease, 98 with ulcerative colitis) were investigated. The influence of time from diagnosis, disease activity, inflammation and the status of iron and hematinic vitamins on the level of hemoglobin and prevalence of anemia were evaluated. In a second group of 27 patients with Crohn's disease, undergoing anti-tumor necrosis factor-alpha treatment with infliximab because of refractory or fistulizing disease, we determined the effects of infliximab on disease activity, hemoglobin, serum erythropoietin levels, iron status and inflammation.
  
  
  RESULTS
  In all, 104 of the 263 patients with inflammatory bowel disease were anemic. Age, gender and azathioprine treatment had no influence on anemia. The prevalence of anemia was highest at diagnosis (65%), decreased during the first 4 years after disease onset, and was stable thereafter. Active disease was associated with higher rates of anemia. At diagnosis most anemic patients had anemia of chronic disease; during follow-up iron deficiency and multifactorial forms of anemia became more prevalent. Eighteen of 27 patients undergoing treatment with infliximab were anemic; most of them had anemia of chronic disease. Infliximab reduced disease activity and improved anemia in 12 patients. This was mediated by an increased production of erythropoietin for the degree of anemia. In vitro infliximab increased the growth of erythroid progenitors from the peripheral blood of patients with active disease. Conclusions Anemia is a common problem in out-patients with inflammatory bowel disease; the prevalence and severity of anemia are related to the activity of the bowel disorder. The pathogenesis of anemia changes during the course of the disease, with anemia of chronic disease having a major role at diagnosis and iron deficiency and multifactorial forms of anemia during follow-up. In patients requiring anti-tumor necrosis factor-alpha treatment, response to therapy improves erythropoiesis.
authors.affiliation: Clinica, Medica I, Policlinico San Matteo, Piazzale Golgi, 27100 Pavia, Italy. n.bergamaschi@smatteo.pv.it
authors.forename: Gaetano
authors.initials: G
authors.lastname: Bergamaschi
authors.forename: Antonio
authors.initials: A
authors.lastname: Di Sabatino
authors.forename: Riccardo
authors.initials: R
authors.lastname: Albertini
authors.forename: Sandro
authors.initials: S
authors.lastname: Ardizzone
authors.forename: Paolo
authors.initials: P
authors.lastname: Biancheri
authors.forename: Elisa
authors.initials: E
authors.lastname: Bonetti
authors.forename: Andrea
authors.initials: A
authors.lastname: Cassinotti
authors.forename: Paolo
authors.initials: P
authors.lastname: Cazzola
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Markopoulos
authors.forename: Alessandro
authors.initials: A
authors.lastname: Massari
authors.forename: Vittorio
authors.initials: V
authors.lastname: Rosti
authors.forename: Gabriele Bianchi
authors.initials: GB
authors.lastname: Porro
authors.forename: Gino R
authors.initials: GR
authors.lastname: Corazza
mesh_terms: D000328:Adult; D000740:Anemia / Q000188:drug therapy* / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D003424:Crohn Disease / Q000150:complications; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015212:Inflammatory Bowel Diseases / Q000150:complications* / Q000188:drug therapy*; D000069285:Infliximab; D000090463:Iron Deficiencies; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors*; D055815:Young Adult
chemical_list: D000893:Anti-Inflammatory Agents; D000911:Antibodies, Monoclonal; D014409:Tumor Necrosis Factor-alpha; D000069285:Infliximab