H⁺ K⁺-ATPase Antibodies in Autoimmune Gastritis: Observations on the Development of Pernicious Anemia

Abstract

The prevalence and development of antibodies to H⁺ K⁺-ATPase were investigated with a sensitive enzyme-linked immunosorbent assay in 86 patients with autoimmune atrophic gastritis (type A). Sixty-nine of the patients had pernicious anemia, and 17 had simple atrophic gastritis. Elevated tilers were found in 93% of pernicious anemia probands. Women had higher levels than men: 3.24 versus 1.58U/1 (p-0.002) (upper reference limit, 0.55 U/1). The antibody levels did not change over 1–4 years, but a gradual decrease in liters over decades was observed. All patients with pernicious anemia had low levels of pepsinogen A, a product of the gastric chief and mucous neck cells (median, 8.5 μg/1; reference range, 10–90 percentile, 64.4–195.5μg/1), and elevated serum gastrin values (>55 pmol/1) were found in 87%. Serum pepsinogen A, but not serum gastrin, correlated with H⁺ K⁺-ATPase antibody tilers (r=0.35, p=0.01). In the 17 cases wilh simple atrophic gastrilis, H⁺ K⁺-ATPase anlibodies correlaled inversely wilh fundic mucosal gland deslruclion. The dala indicate that H⁺ K⁺-ATPase antibody lilers reflect the immune responsiveness of a given patienl as well as Ihe antigenic amounl, dependenl on Ihe degree of mucosal deslruclion and Ihe duration of Ihe disease.

Key Words:

• H⁺ K⁺-ATPase anlibodies
• alrophic gastritis
• auloimmunily
• parielal cell anlibodies
• pepsinogen
• pernicious anemia
• stomach