title: Coombs negative autoimmune hemolytic anemia in Crohn's disease.
abstract: BACKGROUND
  Anemia is a common, important extraintestinal complication of Crohn's disease. The main types of anemia in patients with Crohn's disease are iron deficiency anemia and anemia of chronic disease. Although patients with Crohn's disease may experience various type of anemia, autoimmune hemolytic anemia (AIHA) in patients with Crohn's disease, especially Coombs-negative AIHA, is very rare.
  
  
  METHODS
  A 41-year-old woman with Crohn's disease presented to our emergency room (ER) with dark urine, dizziness, and shortness of breath. The activity of Crohn's disease had been controlled, with Crohn's disease activity index (CDAI) score below 100 point. On physical examination, the patient had pale conjunctivae and mildly icteric sclerae. Serum bilirubin was raised at 3.1 mg/dL, lactate dehydrogenase (LDH) level was 1418 U/L and the haptoglobin level was <3 mg/dL. Results of direct and the indirect Coombs tests were all negative. We then measured the RBC-IgG to evaluate the possibility of Coombs-negative AIHA. The result revealed that RBC-IgG level was 352 IgG molecules/cell, with the cut-off value at 78.5 IgG molecules/cell.
  
  
  CONCLUSIONS
  We report a case of Coombs-negative AIHA in a patient with Crohn's disease with chronic anemia, diagnosed by red blood cell-bound immunoglobulin G (RBC-IgG) and treated with steroids therapy.
authors.affiliation: Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Sihyung
authors.initials: S
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Kyubok
authors.initials: K
authors.lastname: Jin
authors.affiliation: Department of Pathology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Yeon Mee
authors.initials: YM
authors.lastname: Kim
authors.affiliation: Department of Neurology, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Kang Min
authors.initials: KM
authors.lastname: Park
authors.affiliation: Department of Laboratory Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Jeong-Nyeo
authors.initials: JN
authors.lastname: Lee
authors.affiliation: Center of Community Medicine, Jichi Medical University, Tochigi, Japan.
authors.forename: Toyomi
authors.initials: T
authors.lastname: Kamesaki
authors.affiliation: Department of Internal Medicine, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
authors.forename: Yang Wook
authors.initials: YW
authors.lastname: Kim
mesh_terms: D000328:Adult; D000744:Anemia, Hemolytic, Autoimmune / Q000150:complications / Q000175:diagnosis*; D003113:Colonoscopy; D003298:Coombs Test / Q000379:methods*; D003424:Crohn Disease / Q000150:complications / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D014057:Tomography, X-Ray Computed