Advantages of Helicobacter pylori Antigen Test Kit (Colloidal Gold Method) in Primary Screening

Technical Principles and Operating Procedure

The Helicobacter pylori antigen detection kit (colloidal gold method) is based on the principle of double-antibody sandwich immunochromatography. After the fecal sample to be tested is treated with diluent, it is added dropwise to the sample well. The Helicobacter pylori antigen in the sample binds to specific antibodies pre-coated on the nitrocellulose membrane to form an immune complex, which migrates with chromatography to the test line region and reacts with another antibody to produce a visible purplish-red band. The advantage of this method is that it requires no complex equipment, the operating steps are usually no more than 5, and the result interpretation time is generally controlled within 15-20 minutes, making it suitable for use by non-laboratory professionals.

Clinical Application Scenarios and Advantages

In gastroenterology outpatient clinics, health examination centers, and community medical stations, this kit can serve as a preliminary screening tool for Helicobacter pylori infection. Compared with the urea breath test, fecal antigen detection is not affected by recent use of antibiotics or acid-suppressing drugs (although the discontinuation time should be noted), and requires no fasting or special dietary preparation, with better compliance among children, pregnant women, and elderly individuals. In addition, because sample collection is non-invasive, the risk of cross-infection is low, facilitating sample collection and transport. Multiple comparative studies show that commonly available colloidal gold method kits on the market usually have sensitivity and specificity between 85%-95%, but specific performance should be based on the product instructions.

Quality Requirements and Precautions

The kit should be stored in a dry environment at 2-30°C, avoiding freeze-thaw cycles. During use, sampling should be performed according to the instructions, avoiding adding excessive feces or physiological saline to the dilution tube. Result interpretation should be completed within the specified time; weak positive results or band changes appearing after the time limit should not be counted. Some products may have hook effects or rheumatoid factor interference. For patients with suspected positive results but obvious symptoms, further confirmation by pathological biopsy via gastroscopy or culture is recommended. In addition, the kit is only for qualitative detection and cannot replace clinical diagnosis.

Comparison with Other Detection Methods

Gastric biopsy + rapid urease test is the gold standard, but it is invasive and costly; the 13C/14C urea breath test is non-invasive but requires special instruments and breath samples; serological antibody testing cannot distinguish between current and past infection. Helicobacter pylori antigen detection (fecal) has good timeliness in the diagnosis of current infection, especially suitable for large-scale screening and post-treatment follow-up. It should be noted that kits from different manufacturers differ in antigen recognition epitopes, sample dilution ratios, and other aspects, and result interpretation should be combined with clinical findings.