From the Research
Pernicious anemia is diagnosed through several blood tests, with the most important being vitamin B12 levels, complete blood count (CBC), and specific antibody tests, as confirmed by the most recent study 1 in 2023. The diagnosis of pernicious anemia involves a combination of laboratory tests and clinical evaluation.
- A vitamin B12 level below 200 pg/mL strongly suggests deficiency, while the CBC typically shows macrocytic anemia with large red blood cells (elevated MCV) 2.
- Testing for intrinsic factor antibodies and parietal cell antibodies is crucial, as their presence confirms an autoimmune cause, which is a key aspect of pernicious anemia 3.
- Additional helpful tests include methylmalonic acid and homocysteine levels, which are elevated in B12 deficiency even when B12 levels appear borderline, as highlighted in a case report 1.
- A Schilling test was historically used but is rarely performed today, and instead, other tests like complete blood cell count (CBC) and peripheral blood smear are used for evaluation, as recommended in a recent journal article 4.
- If pernicious anemia is diagnosed, treatment involves B12 replacement, typically starting with intramuscular injections of 1000 mcg cyanocobalamin daily or every other day for one week, followed by weekly injections for a month, then monthly for life, as suggested by various studies 2, 5.
- Some patients may eventually switch to high-dose oral B12 supplements (1000-2000 mcg daily), and regular monitoring of B12 levels and blood counts is necessary to ensure adequate treatment response, as emphasized in the literature 3, 4.