Pathology tests database

Sample and container requirements

Serum

Minimum volume required

4 ml Blood

Special requirements

none

Patient preparation

None

Sample viability

7 days when stored at 4C or frozen

Turnaround time

7-14 days

Reference range

Negative <= 20 Equivocal = 20.1- 24.9 Positive >=25.0 A specimen with equivocal levels of Intrinsic Factor antibody cannot be assessed for antibody status. A repeat sample should be taken at a later time.

Clinical guidance

Antibodies against intrinsic factor (IFA) are seen in 50-70% of patients with pernicious anaemia (PA) . Gastric parietal cell antibodies are considered an appropriated screening test for pernicious anaemia and intrinsic factor antibodies are ideally used to confirm if a GPC has been masked by another antibody (for example anti-mitochondrial antibodies) . There are two types of intrinsic factor antibody that can be detected; type I that block the binding of B12 to intrinsic factor and type II that block the uptake of the intrinsic factor-B12 complex. PA is caused by chronic atrophic gastritis and subsequent reduced absorption of vitamin B12 in the ileum. This results in megaloblastic anaemia and often neurological disorders

Notes