~(13)C-urea breath test in the diagnosis of Helicobacter pylori infection in children

Abstract

Objective To evaluate the reliability of 13 C-urea breath test (13C-UBT) in the diagnosis of Helicobacter Pylori (HP) infection in children by using gastroscopy and serum HP antibody study. Methods Totally 589 children with repeatedly occurred epigastric or periumbilical pain were studied from October 1997 to December 1999 in outpatients clinic of gastroenterology of our hospital.The patients′ ages ranged from 4 to 14 years, the average age was 9 years. Of the 589 patients, 435 were examined with 13 C-UBT. After overnight fasting, in the morning each child received a cup of oat meal to delay gastric emptying and 50 mg of 13 C-urea was administrated, and before and 30 minute after the dose, expired gases were collected for analysis with isotope ratio mess spectrometry. The result were expressed as DOB (Delta over baseline). Two hundred and forty-seven and 188 cases have stopped using antibiotics 2 and 4 weeks before examination, respectively. At the same time 41 of 435 cases with serious symptoms were examined with gastroscopy and antral biopsies were obtained for Warthin-Starry staining (W-S stain) and rapid urease test (RUT). Diagnosis of HP infection was made when both examinations were positive. The rate of consistency betwenn 13 C-UBT and gastroscopy, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated. At the same time HP-IgG antibody was examined in 300 of 589 cases, while 13 C-UBT was performed in 146 of 300 cases. The consistency between 13 C-UBT and serum HP-IgG antibody was also calculated. Results Positive results of 13 C-UBT were seen in 27.58% of the patients, the rate of infection rose with increase of patients′ age, which was remarkable after 7 years of age. The rate of infection increased very fast during childhood. The patterns of infection were similar to that in the other developing countries. In patients who had not received antibiotics for 2 weeks and 4 weeks, the rates of HP infection were 27.12% and 28.17%, respectively. The positive rate of serum HP-IgG antibody was 56.7%. The HP like microorganism was seen in histologic study after gastroscopy in 39% of the cases. The consistency rate between gastroscopy and 13C-UBT was 90.24%. The sensitivity, specificity, PPV and NPV were 75%, 100%, 100%, and 86.2%, respectively. The rate of consistency between 13 C-BUT and serum HP-IgG antibody were 63.1%. Conclusions 13 C-UBT is a method with higher sensitivity and high specificity. As a noninvasive method, it is reliable for detection of HP infection in children. There was no significant difference in positive rate of 13 C-UBT between inpatients without antibiotics use for 2 weeks and 4 weeks before examination. Key words: Helicobacter pylori; 13C-urea breath test; Urease