What does a positive intrinsic factor test mean?

A positive IFAB test result indicates the presence of circulating autoantibodies to intrinsic factor. The combination of megaloblastic anemia, low serum vitamin B12, and the presence of serum IFAB strongly supports the diagnosis of pernicious anemia.

What test is done for intrinsic factor?

An intrinsic factor antibody (IF antibody) test may be used to help determine the cause of a vitamin B12 deficiency and to confirm a diagnosis of pernicious anemia. Pernicious anemia is caused by vitamin B12 deficiency due to a lack of intrinsic factor.

What does a deficiency of the intrinsic factor result in?

A lack of intrinsic factor leads to pernicious anemia and vitamin B12 deficiency, which can cause anemia and brain and nervous system (neurological) problems.

What is the normal range for intrinsic factor?

The Intrinsic factor normal range is 1.21 to 1.52 AU/mL. The test will tell you whether you test positive or negative for the Intrinsic factor blocking antibody or Intrinsic factor binding antibody. Less than 1.20 AU/mL is considered negative and more than 1.53 AU/mL is positive.

Is it possible to test for intrinsic factor antibodies?

It is not possible to test for Intrinsic Factor antibodies on patients with a high Vitamin B12 level, for example with patients undergoing B12 replacement therapy. Grossly haemolysed, lipaemic or icteric samples may give erroneous results and will not be processed.

What is intrinsic factor?

Intrinsic Factor is a 50-kDA glycoprotein and belongs to the eukaryotic cobalamin transport proteins family. Intrinsic Factor is secreted by the parietal cells of the stomach and is necessary for absorption of Vitamin B12 in the intestines. After exit from the acidic environment from the stomach,…

When are intrinsic factor antibodies indicated in the evaluation of vitamin B12?

Intrinsic Factor antibodies will be automatically performed if the Vitamin B12 result is <150pg/ml. Intrinsic Factor antibodies will not normally be performed on patients with a normal Vitamin B12 result.

What is the pathophysiology of autoimmune gastritis with intrinsic factor antibodies?

Pernicious Anaemia is a clinical manifestation of autoimmune gastritis and is associated with the presence of intrinsic factor antibodies. There are two types of intrinsic factor antibody: type 1 binds to the vitamin B12 binding site and type 2 hinders the binding site by binding to structures nearby.