A 58-year-old woman has macrocytic anemia, atrophic glossitis, and mild peripheral neuropathy. Anti-parietal cell antibodies are positive. Which finding would be most specific for confirming pernicious anemia as the cause?

• A Anti-parietal cell antibody titer greater than 1:80
• B Anti-intrinsic factor antibody positivity ✓
• C Low serum gastrin level
• D Positive antimitochondrial antibody

Explanation

Antibodies against intrinsic factor are highly specific for pernicious anemia, though less sensitive, whereas anti-parietal cell antibodies occur in up to 90 percent of cases but also in atrophic gastritis and healthy elderly individuals, making them sensitive but nonspecific. Gastrin is characteristically elevated, not low, because achlorhydria removes acid inhibition of G cells. Antimitochondrial antibody points to primary biliary cholangitis.

Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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