Intrinsic Factor Antibodies Test

The Intrinsic Factor Antibodies Test is a targeted blood investigation used to identify the most common autoimmune cause of vitamin B12 deficiency: pernicious anaemia. It is particularly valuable for patients who have been found to have low vitamin B12 levels, those with unexplained anaemia or neurological symptoms, and individuals with a family history of autoimmune conditions. The test works by detecting antibodies directed against intrinsic factor, a protein produced by the stomach lining that is essential for the absorption of vitamin B12 in the small intestine. When these antibodies are present, they bind to intrinsic factor and prevent it from carrying out its role, leading to a functional B12 deficiency even if dietary intake is adequate. This test is typically requested alongside serum vitamin B12 and folate measurements to provide a complete picture of a patient's B12 status. The analytical method used is a standard immunoassay technique, which offers reliable and reproducible results.

Biomarkers
- Intrinsic Factor Antibodies

Why it matters
Identifying intrinsic factor antibodies is a critical step in confirming a diagnosis of pernicious anaemia. Unlike dietary B12 deficiency, which can often be corrected with oral supplements, pernicious anaemia requires lifelong management with regular B12 injections because the body cannot absorb the vitamin through the gut. A positive result therefore has significant implications for treatment and long-term monitoring. It also helps to differentiate pernicious anaemia from other causes of low B12, such as malabsorption due to coeliac disease, Crohn's disease, or bacterial overgrowth, ensuring that patients receive the correct and most effective care. Early detection and appropriate treatment can prevent the progression of potentially irreversible neurological damage and other serious complications associated with untreated B12 deficiency.

Autoimmune Markers
- Intrinsic Factor Antibodies

No special preparation required.

For blood tests, we recommend drinking plenty of water beforehand to ensure smooth sample collection. If you are taking any regular medication, continue to do so unless advised otherwise by your doctor.