Pernicious Anemia Diagnostic Panel:
Fasting Required: No
Lab: Quest Diagnostics
Specimen: Blood
Results: Average processing time 4-7 days
Note: Result turnaround times are an estimate and are not guaranteed. Our reference lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.
Special Instructions: Dietary supplements containing biotin may interfere in assays and may skew results to be either falsely high or falsely low. For patients receiving the recommended daily doses of biotin, draw samples at least 8 hours following the last biotin supplementation. For patients on mega-doses of biotin supplements, draw samples at least 72 hours following the last biotin supplementation.
Discontinue B12 shots and/or supplements for 1 week prior to testing.
Descriptions: This panel tests for anti-intrinsic factor antibodies, vitamin B12, and methylmalonic acid (MMA) and can be used to identify pernicious anemia as the cause of vitamin B12 deficiency. In patients with clinical suspicion of pernicious anemia, the combination of megaloblastic anemia, presence of anti-intrinsic factor antibodies, low level of vitamin B12, and/or high level of MMA confirms the diagnosis.
Pernicious anemia is one of many conditions that lead to vitamin B12 deficiency. Pernicious anemia is caused by the immune system targeting intrinsic factors or parietal cells that make intrinsic factors. Lack of intrinsic factors results in decreased absorption of vitamin B12, a vitamin that is essential for erythropoiesis. Initial screening for vitamin B12 deficiency usually starts with a complete blood count and serum vitamin B12 level. MMA levels represent a more direct measure of the physiologic activity of vitamin B12. Therefore, MMA measurement may help in evaluating vitamin B12 deficiency when the vitamin B12 level is normal or low-normal-particularly when macrocytosis is found.
Anti-intrinsic factor antibodies, found in 40% to 60% of patients with pernicious anemia, are highly specific for pernicious anemia. Therefore, testing for intrinsic factor antibodies may be helpful when dietary vitamin B12 deficiency or malabsorption cannot be identified as the cause of vitamin B12 deficiency. This is especially true for patients with anemia, neuropathy, glossitis, or other autoimmune disorders (eg, Hashimoto disease, type 1 diabetes, vitiligo, and hypoadrenalism). The presence of intrinsic factor antibodies with confirmed vitamin B12 deficiency has a high positive predictive value (95%) for pernicious anemia.
The components of this panel can be ordered individually. The intrinsic factor antibodies test has relatively low sensitivity (40%-60%); thus, a negative result does not rule out pernicious anemia. In patients with negative results for intrinsic factor antibodies but confirmed vitamin B12 deficiency and strong clinical suspicion of pernicious anemia, a high serum gastrin level is consistent with the diagnosis.
The results of this test should be interpreted in the context of pertinent clinical and physical examination findings.
Tests Included:
Intrinsic factor blocking antibody which prevents the binding of vitamin B12 to the intrinsic factor molecule, is present in >50% of all patients with pernicious anemia and only rarely encountered in other conditions. Pernicious anemia is one of the major causes of vitamin B12 deficiency.
Methylmalonic Acid (MMA), Serum is used to help detect early and/or mild vitamin B12 deficiency. Methylmalonic Acid (MMA) is a substance produced when proteins (amino acids) in the body break down.
Vitamin B12 (Cobalamin) is an Essential component in making red blood cells, and is important for nerve cell function. Deficiency can lead to different forms of anemia, as well as impaired liver and kidney function. Vitamin B12 is decreased in pernicious anemia, total or partial gastrectomy, malabsorption and certain congenital and biochemical disorders.
Lab: Quest Diagnostics
Specimen: Blood
Results: Average processing time 4-7 days
Note: Result turnaround times are an estimate and are not guaranteed. Our reference lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance.
Special Instructions: Dietary supplements containing biotin may interfere in assays and may skew results to be either falsely high or falsely low. For patients receiving the recommended daily doses of biotin, draw samples at least 8 hours following the last biotin supplementation. For patients on mega-doses of biotin supplements, draw samples at least 72 hours following the last biotin supplementation.
Discontinue B12 shots and/or supplements for 1 week prior to testing.
Descriptions: This panel tests for anti-intrinsic factor antibodies, vitamin B12, and methylmalonic acid (MMA) and can be used to identify pernicious anemia as the cause of vitamin B12 deficiency. In patients with clinical suspicion of pernicious anemia, the combination of megaloblastic anemia, presence of anti-intrinsic factor antibodies, low level of vitamin B12, and/or high level of MMA confirms the diagnosis.
Pernicious anemia is one of many conditions that lead to vitamin B12 deficiency. Pernicious anemia is caused by the immune system targeting intrinsic factors or parietal cells that make intrinsic factors. Lack of intrinsic factors results in decreased absorption of vitamin B12, a vitamin that is essential for erythropoiesis. Initial screening for vitamin B12 deficiency usually starts with a complete blood count and serum vitamin B12 level. MMA levels represent a more direct measure of the physiologic activity of vitamin B12. Therefore, MMA measurement may help in evaluating vitamin B12 deficiency when the vitamin B12 level is normal or low-normal-particularly when macrocytosis is found.
Anti-intrinsic factor antibodies, found in 40% to 60% of patients with pernicious anemia, are highly specific for pernicious anemia. Therefore, testing for intrinsic factor antibodies may be helpful when dietary vitamin B12 deficiency or malabsorption cannot be identified as the cause of vitamin B12 deficiency. This is especially true for patients with anemia, neuropathy, glossitis, or other autoimmune disorders (eg, Hashimoto disease, type 1 diabetes, vitiligo, and hypoadrenalism). The presence of intrinsic factor antibodies with confirmed vitamin B12 deficiency has a high positive predictive value (95%) for pernicious anemia.
The components of this panel can be ordered individually. The intrinsic factor antibodies test has relatively low sensitivity (40%-60%); thus, a negative result does not rule out pernicious anemia. In patients with negative results for intrinsic factor antibodies but confirmed vitamin B12 deficiency and strong clinical suspicion of pernicious anemia, a high serum gastrin level is consistent with the diagnosis.
The results of this test should be interpreted in the context of pertinent clinical and physical examination findings.
Tests Included:
Intrinsic factor blocking antibody which prevents the binding of vitamin B12 to the intrinsic factor molecule, is present in >50% of all patients with pernicious anemia and only rarely encountered in other conditions. Pernicious anemia is one of the major causes of vitamin B12 deficiency.
Methylmalonic Acid (MMA), Serum is used to help detect early and/or mild vitamin B12 deficiency. Methylmalonic Acid (MMA) is a substance produced when proteins (amino acids) in the body break down.
Vitamin B12 (Cobalamin) is an Essential component in making red blood cells, and is important for nerve cell function. Deficiency can lead to different forms of anemia, as well as impaired liver and kidney function. Vitamin B12 is decreased in pernicious anemia, total or partial gastrectomy, malabsorption and certain congenital and biochemical disorders.