In pernicious anemia, which laboratory profile is typical?

In pernicious anemia, which laboratory profile is typical?

• A. Increased MCV with decreased B12, positive intrinsic factor antibodies, and positive Schilling test
• B. Normal MCV and B12 levels
• C. Increased MCV with decreased B12 and positive intrinsic factor antibodies
• D. Decreased MCV with elevated gastrin

Answer: (C)

Pernicious anemia is an autoimmune loss of intrinsic factor leading to impaired vitamin B12 absorption, which in turn causes defective DNA synthesis in hematopoietic cells andMegalo-blastic, or macrocytic, anemia. The hallmark lab pattern is an increased MCV from macrocytosis, decreased vitamin B12 levels, and antibodies against intrinsic factor, reflecting the autoimmune destruction of the factor needed for B12 absorption. This combination specifically points to pernicious anemia as the cause. Historically, the Schilling test was used to differentiate causes of B12 malabsorption, but it is now largely obsolete and not necessary for the typical diagnostic picture. Elevated gastrin can occur due to reduced acid production from parietal cell loss but does not define the core lab profile for pernicious anemia.

Pernicious anemia is an autoimmune loss of intrinsic factor leading to impaired vitamin B12 absorption, which in turn causes defective DNA synthesis in hematopoietic cells andMegalo-blastic, or macrocytic, anemia. The hallmark lab pattern is an increased MCV from macrocytosis, decreased vitamin B12 levels, and antibodies against intrinsic factor, reflecting the autoimmune destruction of the factor needed for B12 absorption. This combination specifically points to pernicious anemia as the cause.

Historically, the Schilling test was used to differentiate causes of B12 malabsorption, but it is now largely obsolete and not necessary for the typical diagnostic picture. Elevated gastrin can occur due to reduced acid production from parietal cell loss but does not define the core lab profile for pernicious anemia.