Stool antigen for the diagnosis of Helicobacter pylori infection in cirrhosis: comparative usefulness of three different methods

Abstract

Summary Background : Helicobacter pylori infection may lead to peptic ulcer disease, and causes significant morbidity in patients with cirrhosis. The measurement of H. pylori antigens in human stools has been proposed as a valuable, non‐invasive, diagnostic tool. A number of tests have recently been commercialized. However, very few data are available on their reliability in patients with cirrhosis. Aim : To evaluate the usefulness of three new tests — HpSA (Meridian Diagnostics Inc., Cincinnati, OH, USA), Simple H. pyl (OPERON S.A., Zaragoza, Spain) and FemtoLab H. pylori (Connex, Martinsried, Germany) — in the diagnosis of H. pylori infection in cirrhotic patients. Methods : H. pylori infection was determined in 79 cirrhotic patients (48 men, 31 women; age range, 29–82 years; mean, 62 ± 11 years) by concordance of histology and urea breath test. The sensitivity, specificity and positive and negative predictive values of each stool test were calculated. Results : According to the reference method, the sensitivities of HpSA, Simple H. pyl and FemtoLab H. pylori immunoassays were 76%, 87% and 78%, respectively, and their specificities were 93%, 62% and 79%, respectively. Conclusions : Faecal tests are non‐invasive and easy‐to‐perform tools for the diagnosis of H. pylori infection. However, their sensitivity and specificity seem to be non‐optimal in patients with cirrhosis.

Accuracy of Monoclonal Stool Tests for Determining Cure of Helicobacter pylori Infection After Treatment

“…In the remaining patients H. pylori infection was determined by urea breath test. Gold standard for H. pylori infection was determined as follows: patients with a strongly positive urea breath test (ΔUBT > 20) [5] or a positive histology were considered treatment failures and received second‐line treatment. Patients with a weakly positive test (ΔUBT 5–20) underwent a second urea breath test to confirm persistence of the infection.…”

Diagnosis of Helicobacter pylori infection

“…Among patients with liver cirrhosis [41], HpSA test showed a low sensitivity (75.4%) although the specificity was good (94.1%). In addition, two other stool antigen tests based on monoclonal antibodies showed poor results in this particular group of patients [42]. In one of the studies mentioned above [39] a new polyclonal antibody based faecal test was compared with the HpSA test and found to give comparable results.…”

Comparative Accuracy of 3 Monoclonal Stool Tests for Diagnosis ofHelicobacter pyloriInfection among Patients with Dyspepsia

“…Fecal immunoassays perform far more irregularly than other methods do, and indeed the diagnostic accuracy of the different stool tests varies widely [2,3]. One of the reasons for this variation in accuracy is that the antibody composition of the tests that use polyclonal antibodies may change from batch to batch, thus presenting major intratest variability [4][5][6]. Therefore, polyclonal tests are clearly less reliable than are monoclonal tests or urea breath tests [3].…”