The anti-inner antibody is an autoantibody against an internal factor and belongs to IgG. Anti-internal factor antibodies can be present in the patient's serum, gastric juice and saliva. Anti-internal factor antibodies can cause gastric mucosal atrophy, inhibit the activity of internal factors and decrease the concentration of vitamin B12 in the blood, leading to pernicious anemia and neurological symptoms. Determination of anti-internal factor antibodies may be helpful in the diagnosis of pernicious anemia. The internal factor is a glycoprotein that binds to vitamin B12 to form a complex that binds to the receptor in the ileal mucosa and is absorbed. Anti-internal factors (AIFA) are divided into two types: type I is a blocking antibody that inhibits the binding of endogenous factors to vitamin B12; type II is a binding antibody that binds to the inner factor-vitamin B12 complex and blocks the complex and ileal mucosal receptors. Attachment.

Basic Information

Specialist classification: growth and development check classification: immunological examination

Applicable gender: whether men and women apply fasting: not fasting

Analysis results:

Below normal:

Normal value:

Above normal:


Positive is seen in pernicious anemia.

Reminder: The reaction of antigen and antibody is carried out in the well of a solid phase carrier, polystyrene microtiter plate. After each reagent is added, the excess free reactant can be removed by washing to ensure the test result. Specificity and stability. Normal value

negative. The literature reports that the positive rate of normal people is <1%.

Clinical significance

Positive is seen in pernicious anemia. In addition, hyperthyroidism, diabetes, chronic thyroiditis, iron deficiency anemia can sometimes be positive.


Anti-internal factor antibodies are commonly determined by ELISA. ELISA is a highly sensitive test technique that combines the specific reaction of antigens and antibodies with the efficient catalysis of enzymes on substrates based on immunological reactions. The reaction of the antigen and the antibody is carried out in a well of a solid phase carrier, a polystyrene microtiter plate, and after each reagent is added, the excess free reactant can be removed by washing to ensure the specificity of the test result. stability.

Inspection process

Determined by the RIA method.

Not suitable for the crowd

There are no taboos.

Adverse reactions and risks

There are no related complications and hazards.