Home Biomarkers Helicobacter Pylori Abs.(IgG)

Helicobacter Pylori Abs.(IgG)

Bacterial infections Biomarker

Sample Needed

Collection Type: Blood

Body System

Related System: Bacterial infections

Overview

Helicobacter pylori IgG (H. pylori Abs. IgG) is a blood test that detects IgG antibodies produced by the immune system in response to H. pylori, a bacterium that colonizes the stomach lining. The test measures prior or current exposure to H. pylori rather than directly detecting the organism. It is used when peptic ulcer disease, chronic gastritis, dyspepsia, unexplained iron-deficiency anemia, or a family history of gastric cancer are suspected. Symptoms prompting testing include persistent upper abdominal pain, bloating, nausea, vomiting, black or tarry stools, or unintentional weight loss. Seropositivity rises with age and is more common in populations with higher infection prevalence; children are less likely to be positive. Results are similar across genders though prevalence varies by region and socioeconomic factors.

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Test Preparation

No special preparation is required

Why Do I Need This Test

Profile: Bacterial infections (H.
pylori serology) - Symptoms indicating testing: chronic dyspepsia, recurrent peptic ulcer symptoms, unexplained iron-deficiency anemia, chronic gastritis signs - Conditions diagnosed/monitored: prior or current H.
pylori infection, risk assessment for peptic ulcer and gastric mucosal disease - Reasons for abnormal levels: past or current infection (positive), recent infection not yet seroconverted (false negative), immunosuppression (reduced antibody response) - Biological meaning of abnormal values: presence of IgG indicates immune exposure to H.
pylori but does not prove active infection - Behaviors/lifestyle causing abnormal values: crowded living conditions, poor sanitation, smoking, and household transmission increase infection risk - Family history: first-degree relatives with peptic ulcer disease or gastric cancer increases index of suspicion

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Understanding Test Results

<20 U/mL (negative): No detectable IgG antibodies suggests no prior exposure or very remote/past infection with waned antibodies; however early infection (before seroconversion) or immunosuppression can produce false negatives.
For suspected active infection with negative serology, use stool antigen or urea breath test.
20–30 U/mL (equivocal/gray zone): Indeterminate—repeat testing in several weeks or use an alternative diagnostic test (breath/stool) and correlate clinically.
>30 U/mL (positive): Detectable IgG consistent with prior or current H.
pylori exposure.
Higher titers increase likelihood of infection but do not reliably distinguish active from past/treated infection.
After successful eradication, IgG can remain positive for months to years; therefore serology is not recommended to confirm eradication.
Very high values together with compatible symptoms raise suspicion for active disease and warrant confirmation with tests that detect current infection (urea breath test, stool antigen, or endoscopic biopsy where indicated).

Normal Range

0–20 U/mL

FAQs

Q: What does Helicobacter pylori IgG Ab positive mean?

A: An Helicobacter pylori IgG antibody positive result means your immune system has been exposed to H. pylori, indicating past or possible current infection. IgG antibodies can persist after eradication, so this test cannot reliably distinguish active infection. Clinical symptoms and confirmatory tests (urea breath, stool antigen, or endoscopic biopsy) are needed to confirm active infection and decide on treatment.

Q: Is Helicobacter pylori good or bad?

A: Helicobacter pylori is a common stomach bacterium that is neither purely good nor purely bad. Many people carry it without symptoms, but it can cause chronic gastritis, peptic ulcers and increase stomach cancer risk. Eradication is recommended for ulcers, certain infections, and higher cancer-risk patients. Some studies suggest it may reduce reflux and allergy risks, but its potential harm typically outweighs these benefits.

Q: What is the normal range for Helicobacter pylori IgG?

A: Normal (negative) Helicobacter pylori IgG results vary by laboratory and assay but are typically below the lab’s specified cutoff—commonly less than 10–20 U/mL (or an index <1.0). Values in a borderline range depend on the assay; values above the laboratory’s positive threshold (often ≥20–30 U/mL or index ≥1.0) indicate past or current infection. Interpret results with your lab’s reference range and clinical context.

Q: How to remove H. pylori from the stomach?

A: Treat H. pylori by seeing a doctor for confirmed testing, then complete prescribed eradication therapy—typically a proton pump inhibitor plus two antibiotics (or bismuth quadruple therapy) for about 10–14 days. Finish the full course, avoid NSAIDs and smoking, and have a follow-up test (urea breath or stool antigen) at least four weeks after treatment to confirm eradication.

Q: How long does H. pylori IgG stay positive?

A: H. pylori IgG antibodies often persist for months to years after infection. Levels typically begin to fall within months but can remain detectable for 6–12 months or longer, sometimes over a year, so IgG tests aren’t reliable for confirming eradication. For test-of-cure, breath tests, stool antigen tests, or biopsy-based methods are recommended.

Q: Can Helicobacter pylori come back after treatment?

A: Yes. Helicobacter pylori can recur after treatment due to incomplete eradication (recrudescence) or new infection. Standard therapy cures most people, but antibiotic resistance and treatment failure occur. Reinfection rates are low in adults in high-income settings (a few percent per year) but higher in low-resource areas. Test-of-cure (urea breath or stool antigen) is recommended to confirm eradication and guide retreatment if needed.