title: The Diagnostic Validity of Citric Acid-Free, High Dose (13)C-Urea Breath Test After Helicobacter pylori Eradication in Korea.
abstract: BACKGROUND
  The (13)C-urea breath test ((13)C-UBT) is a noninvasive method for diagnosing Helicobacter pylori (H. pylori) infection. The aims of this study were to evaluate the diagnostic validity of the (13)C-UBT cutoff value and to identify influencing clinical factors responsible for aberrant results.
  
  
  METHODS
  (13)C-UBT (UBiTkit; Otsuka Pharmaceutical, cutoff value: 2.5‰) results in the range 2.0‰ to 10.0‰ after H. pylori eradication therapy were compared with the results of endoscopic biopsy results of the antrum and body. Factors considered to affect test results adversely were analyzed.
  
  
  RESULTS
  Among patients with a positive (13)C-UBT result (2.5‰ to 10.0‰, n = 223) or a negative (13)C-UBT result (2.0‰ to < 2.5‰, n = 66) after H. pylori eradication, 73 patients (34.0%) were false positive, and one (1.5%) was false negative as determined by endoscopic biopsy. The sensitivity, specificity, false-positive rate, and false-negative rate for a cutoff value of 2.5‰ were 99.3%, 47.1%, 52.9%, and 0.7%, respectively, and positive and negative predictive values of the (13)C-UBT were 67.3% and 98.5%, respectively. Multivariate analysis showed that a history of two or more previous H. pylori eradication therapies (OR = 2.455, 95%CI = 1.299-4.641) and moderate to severe gastric intestinal metaplasia (OR = 3.359, 95%CI = 1.572-7.178) were associated with a false-positive (13)C-UBT result.
  
  
  CONCLUSIONS
  The (13)C-UBT cutoff value currently used has poor specificity for confirming H. pylori status after eradication, and this lack of specificity is exacerbated in patients that have undergone multiple prior eradication therapies and in patients with moderate to severe gastric intestinal metaplasia. In addition, the citric-free (13)C-UBT would increase a false-positive (13)C-UBT result.
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Yong Hwan
authors: YH
authors: Kwon
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.|Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors: Nayoung
authors: N
authors: Kim
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Ju Yup
authors: JY
authors: Lee
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Yoon Jin
authors: YJ
authors: Choi
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Kichul
authors: K
authors: Yoon
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Jae Jin
authors: JJ
authors: Hwang
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Hyun Joo
authors: HJ
authors: Lee
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: AeRa
authors: A
authors: Lee
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Yeon Sang
authors: YS
authors: Jeong
authors: Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors: Sooyeon
authors: S
authors: Oh
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Hyuk
authors: H
authors: Yoon
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Cheol Min
authors: CM
authors: Shin
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.
authors: Young Soo
authors: YS
authors: Park
authors: Internal Medicine, Seoul National University Bundang Hospital, Seongnam, South Korea.|Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, South Korea.
authors: Dong Ho
authors: DH
authors: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001944:Breath Tests; D002247:Carbon Isotopes / Q000032:analysis; D019343:Citric Acid; D004724:Endoscopy; D005189:False Positive Reactions; D005260:Female; D016481:Helicobacter Infections / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D056910:Republic of Korea; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014508:Urea / Q000378:metabolism*; D055815:Young Adult
chemical_list: D002247:Carbon Isotopes; D019343:Citric Acid; D014508:Urea
keywords: 13C-urea breath test; Helicobacter pylori; citric acid; cutoff value; eradication