Pernicious Anemia
Pernicious anemia (PA) is a common type of macrocytic anemia caused by a B12
deficiency (Huether & McCance, 2017). Macrocytic anemias are categorized by remarkably
large stem cells called megaloblasts (Huether & McCance, 2017). The megaloblasts mature into
erythrocytes in the bone marrow, which are also significant in size, thickness, and have a large
volume (Huether & McCance, 2017).
In PA, the underlying modification is the absence of intrinsic factor (Huether &
McCance, 2017). Intrinsic factor is required for gastric absorption to process vitamin B12
(Huether & McCance, 2017). B12 is vital for the body to have nuclear maturation and DNA
synthesis in the red blood cells (Huether & McCance, 2017). When a patient has a deficiency in
intrinsic factor, it can be linked as a congenital or an autoimmune progression that is focused
against gastric parietal cells (Huether & McCance, 2017). In most cases, autoimmune gastritis is
the cause of PA (Huether & McCance, 2017). In autoimmune gastritis, gastric atrophy occurs,
leading to destruction of parietal and zymogenic cells (Huether & McCance, 2017). PA patients
typically have autoantibodies that fight the gastric H+ -K+ ATPase, which is an essential protein
component in the parietal cell membranes (Huether & McCance, 2017). When gastric atrophy
