Intrinsic Factor Antibody By IFA Serum

This test is done to establish the cause of Vitamin B12 deficiency. Vitamin B12 deficiency can occur due to dietary imbalance, Intrinsic factor antibody or parietal cell antibody. Establishing the cause of deficiency can help guide appropriate treatment

Intrinsic factor is a glycoprotein produced by the parietal cells of the stomach. It plays an important role in the absorption of vitamin B12 in the small intestine, and its absence can lead to a condition called pernicious anemia (PCA). In the absorption of vitamin B12, intrinsic factor is essential in forming a complex with the vitamin that can be absorbed by ileal receptors. The release of intrinsic factor is partially controlled by gastrin and partially by histamine.

Common indications are :

• Suspected PCA or vitamin B12 deficiency
• Investigation of malabsorption problems
• Evaluation of recurrent or persistent megaloblastic anemias
• Follow-up after gastrectomy
• Assessment of hemolytic anemia
• Diagnosis of Crohn’s disease
• Analysis of macrocytosis in a complete blood count (CBC)
• Evaluation of abdominal pain, fatigue, and other nonspecific signs and symptoms.

This test measures antibodies against Intrinsic factors. This factor helps in the absorption of vitamin B12

This test requires a blood sample. A tourniquet (elastic) band is placed tightly on the upper arm. The patient is then asked to make a fist. This helps in the build-up of blood filling the veins. The skin is disinfected before needle insertion and the blood sample is collected in a vacutainer

Absence of antibodies against Intrinsic factors rules out this as a cause of Vitamin B12 deficiency.
The presence of antibodies against Intrinsic factors confirms the cause of vitamin B12 deficiency. This may coexist with parietal cell antibody also.

The intrinsic factor typically ranges from 1.21 to 1.52 AU/mL. Depending on the outcome of the test, you may test positive or negative for an intrinsic factor-blocking antibody or an intrinsic factor-binding antibody. Positive values range from more than 1.53 AU/mL to less than 1.20 AU/mL, which is considered negative.

When an intrinsic factor-blocking antibody is negative, it means that the body does not have any antibodies that are blocking the absorption of vitamin B12. This indicates that the person does not have a condition like PCA, which is caused by the body producing antibodies that block the absorption of vitamin B12.

Anti-IFAs and anti-parietal cell antibodies are the two forms of autoantibodies seen in PCA. The majority of people with PCA have anti-parietal antibodies.

YYes, there are some risks associated with taking the IFA by IFA serum test. These include the possibility of an allergic reaction to the injection, as well as the risk of developing a false-positive or false-negative result. In rare cases, the test may cause an anaphylactic reaction. Additionally, as this test is highly sensitive, it can detect even very small amounts of intrinsic factor in the blood, which could lead to a false-positive result.
 

Other tests that may be ordered along with an IFA by IFA Serum Test include:

• Vitamin B12 levels,
• Homocysteine and Methylmalonic acid levels,
• Folate levels, and
• Complete Blood Count (CBC).

IF antibody

IFAb