Helicobacter pylori (H. pylori) is a common bacterium that can inhabit the stomach. While many individuals carry this bacterium without experiencing symptoms, it can lead to various digestive issues for some. Medical professionals utilize antibody tests to determine if a person has been exposed to infections, and the H. pylori IgG test serves this purpose.
Understanding H. pylori and IgG Antibodies
H. pylori is a spiral-shaped bacterium that resides in the stomach lining. It is a widespread infection, affecting many globally. While many infected individuals remain asymptomatic, the bacterium can cause inflammation of the stomach lining (gastritis) and peptic ulcers.
Antibodies are proteins generated by the immune system to identify and neutralize foreign substances. Immunoglobulin G (IgG) is the most abundant type of antibody in the blood. IgG antibodies are particularly important in the body’s secondary immune response, indicating either a past or current infection with a specific pathogen, like H. pylori.
The H. pylori IgG Test Explained
The H. pylori IgG test is a blood test designed to detect the presence of IgG antibodies specific to H. pylori. A positive result suggests that an individual has been exposed to the bacterium at some point. This test is performed through a routine blood draw.
Doctors may order this test when a patient presents with symptoms commonly associated with H. pylori infection. These symptoms can include persistent indigestion, abdominal pain, bloating, nausea, vomiting, or unexplained weight loss. The test helps determine if H. pylori is a possible cause of these digestive complaints.
Interpreting Your H. pylori IgG Results
A positive H. pylori IgG test result indicates that IgG antibodies to the bacterium were detected in the blood. This means the immune system has responded to H. pylori, suggesting either a current infection or a past infection that has since resolved. This test cannot differentiate between an active, ongoing infection and a previous one, as IgG antibodies can persist in the bloodstream after the bacteria have been eradicated.
Conversely, a negative H. pylori IgG result typically means that no IgG antibodies to the bacterium were detected, suggesting no prior or current H. pylori infection. However, false-negative results can occur, particularly in the very early stages of an infection when antibody levels may not yet be high enough to be detected. False positives are less common but are possible. Due to its inability to distinguish between active and past infections, the IgG test is primarily used for initial screening and may require confirmation with other diagnostic methods for active infection.
Next Steps After a Positive H. pylori IgG Test
A positive H. pylori IgG test result often prompts further diagnostic testing to confirm an active infection. Common confirmatory tests include the urea breath test (UBT) or a stool antigen test (SAT). These non-invasive tests are preferred for detecting active infection and for confirming eradication after treatment, as they directly identify the presence of the bacterium or its byproducts. In some cases, an endoscopy with biopsy may be performed, allowing for direct visualization of the stomach lining and collection of tissue samples for analysis.
If an active H. pylori infection is confirmed, treatment typically involves a combination of medications. This usually includes two or three different antibiotics to eradicate the bacteria, along with an acid-reducing medication, such as a proton pump inhibitor (PPI). The PPI helps reduce stomach acid, aiding antibiotic effectiveness. After completing the prescribed treatment, follow-up testing, with a urea breath test or stool antigen test, is recommended at least four to six weeks later to ensure the infection has been successfully eradicated.