Test ID PCAB Parietal Cell Antibodies, IgG, Serum
Reporting Name
Parietal Cell Ab, IgG, SUseful For
Evaluating patients suspected of having pernicious anemia or immune-mediated deficiency of vitamin B12 with or without megaloblastic anemia
Specimen Type
SerumSpecimen Required
Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Specimen Volume: 0.5 mL
Specimen Minimum Volume
0.45 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 21 days | |
Frozen | 21 days |
Reference Values
Negative: ≤20.0 Units
Equivocal: 20.1-24.9 Units
Positive: ≥25.0 Units
Reference values apply to all ages.
Day(s) and Time(s) Performed
Tuesday, Friday; 3 p.m.
Test Classification
This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
83516
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
PCAB | Parietal Cell Ab, IgG, S | 40960-7 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
PCAB | Parietal Cell Ab, IgG, S | 40960-7 |
Clinical Information
Pernicious anemia (PA) is characterized by atrophic body gastritis (ABG) and is the end state of a progressive disease known as autoimmune chronic atrophic gastritis.(1) In this disease, immune-mediated inflammation leads to destruction of gastric parietal cells with the resultant loss of intrinsic factor production and the inability to absorb dietary vitamin B12. Diagnosis of PA involves demonstrating the presence of a macrocytic anemia in the context of vitamin B12 deficiency, as well as documenting positive autoantibody serology, specifically anti-parietal cell antibody (PCA) and intrinsic factor antibody (IFA).(2) PCAs bind to the alpha- and beta-subunits of the membrane-bound H(+)/K(+)-ATPase. In contrast, IFAs bind directly to intrinsic factor, blocking its ability to bind vitamin B12.(1,2) Both PCAs and IFAs are useful diagnostic markers for PA. In a recently published study, PCAs were 81% sensitive and 90% specific for ABG, while IFAs were 27% sensitive and 100% specific. The study concluded that a combination of PCA and IFA testing was the optimal strategy for the evaluation of patients with suspected PA.(4)
Interpretation
A positive result indicates the presence of IgG antibodies to H(+)/K(+) ATPase and suggests the possibility of pernicious anemia (PA) or a related autoimmune disease.
A negative result indicates no detectable IgG antibodies to H(+)/K(+) ATPase; it does not rule out PA.
An equivocal result is indeterminate.
Clinical Reference
1. Toh BH, Van Driel IR, Gleeson PA: Pernicious anemia. N Eng J Med 1997;337(20):1441-1448
2. Lahner E, Annibale B: Pernicious anemia: new insights from a gastroenterological point of view. World J Gastroenterol 2009;15(41):5121-5128
3. Lahner E, Normal GL, Severi C, et al: Reassessment of intrinsic factor and parietal cell autoantibodies in atrophic gastritis with respect to cobalamin deficiency. Am J Gastroenterol 2009;104(8):2071-2079
4. Product Insert: QUANTA Lite GPA, INOVA Diagnostics, Inc., San Diego, CA
Analytic Time
1 dayMethod Name
Enzyme-Linked Immunosorbent Assay (ELISA)