What this test measures
Helicobacter pylori is a gram-negative bacterium that colonises the stomach lining and causes chronic gastritis, peptic ulcers, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, and increases the risk of gastric adenocarcinoma. The IgG antibody is the longest-lived antibody response — it develops weeks after infection and persists for months to years after eradication.
IgG serology is the most sensitive H. pylori antibody test, but it has a key limitation: it cannot distinguish active infection from previously treated infection. Modern guidelines favour active-infection tests — urea breath test or stool antigen — for diagnosis in symptomatic patients.
Why it matters
In India, H. pylori prevalence reaches 60–80% in adults — one of the highest in the world. Most infections are silent, but H. pylori causes the majority of peptic ulcers and a significant fraction of gastric cancer cases. Eradication relieves dyspepsia, heals ulcers, and reduces gastric cancer risk in high-prevalence populations like India.
IgG serology is useful in: epidemiological studies; cases where active-infection tests cannot be done (recent PPI or antibiotic use that gives false-negative urea breath / stool antigen); and patients with bleeding peptic ulcers where false-negatives of other tests are common. For test-of-cure after eradication, IgG is NOT suitable — antibodies persist for months to years; use urea breath test or stool antigen at least 4–6 weeks after completing therapy.
How to prepare
No fasting required. Continue all medications. Unlike urea breath test or stool antigen, the antibody test is not affected by proton-pump inhibitors or recent antibiotics. Stop biotin supplements 48 hours before the test if you are taking them.
Markers & reference ranges
Reference ranges below are typical adult values. Your lab's reported range may differ slightly based on the assay platform and patient demographics — always read your report against the range printed on it.
| Marker | Normal range | If low | If high |
|---|---|---|---|
| H. pylori IgG (Index / U/mL)[1][2][3] | Negative (assay-specific cut-off) | Negative: no past or current H. pylori infection — or infection too recent (< 1 month) for IgG to develop. False-negatives are uncommon. If clinical suspicion is high (active peptic ulcer disease), confirm with urea breath test or stool antigen. | Positive: confirms exposure to H. pylori at some point. Does NOT distinguish active from previously treated infection. In a previously untreated patient, supports current infection and warrants eradication. In someone with prior treatment, follow up with urea breath test or stool antigen to confirm active infection before re-treating. |
H. pylori test comparison
| Test | Detects | Best use |
|---|---|---|
| IgG antibody (this test) | Past or current exposure | Diagnosis where breath/stool unavailable; bleeding ulcers |
| Urea breath test | Active infection | First-line diagnosis and test of cure |
| Stool antigen | Active infection | First-line diagnosis and test of cure; preferred in children |
| Rapid urease (CLO) on biopsy | Active infection | When endoscopy is being done anyway |
| Histology on biopsy | Active infection + tissue damage | When endoscopy is needed |
Frequently asked questions
Does a positive IgG mean I have H. pylori now?
Not necessarily. IgG persists for months to years after eradication. In a previously untreated patient with relevant symptoms a positive IgG is supportive, but ideally confirm active infection with a urea breath test or stool antigen before starting antibiotics.
Why use IgG when breath and stool tests are better?
IgG is reliable when the patient cannot stop a PPI (which causes false-negative urea breath / stool antigen), in actively bleeding peptic ulcer disease (where other tests have high false-negative rates), in remote settings without access to breath test analysers, and in epidemiology research.
Should I be tested if I have no symptoms?
Routine screening of asymptomatic adults is not generally recommended in India. Testing is indicated in: dyspepsia, peptic ulcer disease, long-term NSAID or aspirin use, family history of gastric cancer, MALT lymphoma, iron-deficiency anemia of unclear cause, and ITP.
How is H. pylori treated?
A 14-day combination of a PPI + two antibiotics (clarithromycin-based triple therapy where resistance is low) or PPI + bismuth + tetracycline + metronidazole (bismuth quadruple therapy) where clarithromycin resistance is high — which now includes much of urban India. Confirm cure with urea breath test or stool antigen 4–6 weeks later.
Can the test be used after treatment?
No — IgG antibody is NOT a test of cure. It can stay positive for months to years even after successful eradication. Use urea breath test or stool antigen for test of cure.
Why is H. pylori so common in India?
It spreads through contaminated water, food, and close family contact in early childhood. Crowding, sanitation gaps, and shared utensils mean most Indians acquire H. pylori before age 10 and carry it into adulthood. Treatment rates are rising as testing becomes more accessible.
Related Immunology tests
Tests commonly ordered alongside HELICOBACTER PYLORI - IGG, or that help interpret an unexpected result.
Sources & references
- NCBI StatPearls — Helicobacter pylori · accessed 2026-05-30T00:00:00.000Z
- ACG Guideline — Treatment of Helicobacter pylori Infection · accessed 2026-05-30T00:00:00.000Z
- NIH MedlinePlus — H. pylori Tests · accessed 2026-05-30T00:00:00.000Z
Book with Zelnoo
Get your HELICOBACTER PYLORI - IGG test done at home — transparent prices, NABL-accredited labs.
Zelnoo lets you compare diagnostic test prices across NABL-accredited labs in Mumbai & Thane, book a free home phlebotomist visit, and receive digital reports in 24–48 hours into a consent-first report vault. No subscriptions, no membership fees — pay only for the test you book.
Book HELICOBACTER PYLORI - IGG now