Parietal Cell Antibody ELISA and Intrinsic Factor Antibody Ban-Hock Toh MBBS, DSc, FRACP, FRCPA Emeritus Professor, Monash University Immunopathologist, Australian Clinical labs Phadia user group meeting Rydges Sydney Airport Hotel, Dreamliner 1 Room 23rd November 2017 Parietal Cell Antibody = Autoimmune Gastritis (Asymptomatic) Parietal cell antibody is a serum diagnostic marker for autoimmune gastritis identified by gastric biopsy Autoimmune Gastritis affects Fundus, spares Antrum Parietal cells produce • Acid (Iron absorption) Parietal, Parietal cells • Intrinsic factor cells (B12 absorption) Destroyed • Iron def anemia • B12 def (Pernicious) anemia Antral G cells produce gastrin Autoimmune Gastritis c i t a m o 10-20 yrs t p m Parietal y s A Chronic Atrophic Gastritis Cell Antibody Parietal cell destruction to gastric Loss of acid and intrinsic factor H/K Intrinsic factor antibody ATPase Fe-deficient/Pernicious/anaemia Autoimmune Gastritis progresses to Atrophic Gastritis Autoimmune Gastritis Gastric Atrophy Whittingham S, Mackay I and Toh BH. Current medical literature-Gastroenterology 2007, 26: 29-36. End-Stage Chronic Atrophic Gastritis of Fundus sparing Antrum ANTRUM FUNDUS (Corpus) (Body) Ian Mackay Intestinal Metaplasia: mucous cells replace parietal, zymogenic and ECL cells Premalignant Gastric cancer Ian Mackay Parietal cell antibodies Parietal cell antibodies target gastric H/K ATPase a and b subunits a b Immunoblotting of stomach membranes with parietal cell antibody Callaghan J, Khan A, Alderuccio F, van Driel I Gleeson P, Toh BH. Autoimmunity. 1993;16:289 b subunit of the gastric H/K ATPase is a heavily glycosylated 35 kDa core protein Proc Nat Acad Sci, 1990; 87, 6418-6422 60-90 kd The 60-90 kDa parietal cell autoantigen associated with autoimmune b subunit gastritis is a b subunit of the gastric H/K ATPase (proton pump) Toh BH et al 35 kd core protein