The diagnosis of Helicobacter pylori infection is a crucial step in the management of various gastrointestinal diseases, including gastritis, peptic ulcers, and gastric cancer. Traditional methods—such as gastroscopy with biopsy or urease testing—are considered the “gold standard”, but they are invasive and expensive. For this reason, in recent years, non-invasive tests based on fecal antigen detection have taken on a central role in the diagnosis and monitoring of infection eradication.
The study
At the Bianalisi Clinical Pathology, Microbiology, and Virology Laboratory in Carate Brianza (MB), Cristina Lapucci and colleagues conducted a validation study to compare the performance of the method traditionally used in the laboratory (Beta Diagnostici antigen card) with a new fully automated turbidimetric method, PYLiaGold, performed on the SENTiFIT 270 Analyzer platform.
Materials and methods
A total of 678 routine samples were analyzed, of which approximately 20% tested positive in the card test. Each sample was resuspended in the dedicated PYLiaGold pierceTube device and analyzed simultaneously using both methods, performing tests on two different batches for a total of 2,712 overall results.
Results
After excluding sessions with out-of-range quality controls, 1,965 valid tests were considered, showing a high degree of agreement between the two batches of PYLiaGold reagent analyzed. Using a cut-off of 0.47 ng/mL, the Cohen’s kappa value was 0.63, indicating substantial agreement between the methods, and the positive predictive value (PPV) and negative predictive value (NPV) were 95% and 89.8%, respectively. The cut-off of 0.47 ng/mL was therefore identified as offering the best balance between sensitivity and specificity.
Conclusions
The automated PYLiaGold assay on the SENTiFIT 270 Analyzer has proven to be a valid alternative to traditional tests, guaranteeing:
- analytical reproducibility greater than 90%,
- fully automated and standardized sample management,
- reduced operator variability.
The trial also confirmed the importance of proper pre-analytical management, emphasizing that analysis within 72 hours of collection and staff training are key factors in obtaining reliable results.
In summary
The new PYLiaGold test represents a significant step forward in the automation and standardization of H. pylori fecal antigen testing, offering clinical laboratories an efficient, accurate, and fully automated solution.