Complement-fixing gastric parietal cell autoantibodies. A good marker for the identification of type A chronic atrophic gastritis.
Using an indirect immunofluorescence (IIF) technique, gastric parietal cell autoantibodies of IgG class (GPCA-IgG) were found in 2% of a normal population, in 5-26% of organ-specific autoimmune subjects and in 100% of patients with pernicious anaemia. With the exception of subjects with alopecia, there was a significantly increased prevalence of GPCA-IgG in autoimmune patients with respect to normal controls. GPCA of IgA class were detected in 22% of GPCA-IgG positive subjects, whereas GPCA of IgM class were uncommon. One-hundred and fifteen subjects underwent gastroscopy and body mucosal biopsy. Histopathological findings of chronic atrophic gastritis (CAG) were present in 71% of GPCA-IgG positive autoimmune patients without pernicious anaemia, in 100% of GPCA-IgG positive patients with pernicious anaemia, and in 20% of GPCA negative autoimmune patients. Complement-fixation test was performed in 46 GPCA-IgG positive subjects without pernicious anaemia using the IIF method. Twenty-nine patients (63%) were found to fix complement fractions till C9 (CF-GPCA) together with properdin factor, and in 25 of them (86%) the histological examination of body gastric mucosa disclosed a CAG (P = 0.0003 versus GPCA-IgG positive/CF negative controls). No significant difference was observed for the prevalence of CAG in GPCA-IgG positive/CF negative subjects with respect to GPCA-IgG negative control group. We conclude that the presence of CF-GPCA represents a useful immunological marker in the identification of CAG, while no predictive value seems to be associated with non-complement fixing GPCA-IgG.
Betterle
C
C
Istituto di Semeiotica Medica, Università di Padova, Italy.
Mazzi
P A
PA
Pedini
B
B
Accordi
F
F
Cecchetto
A
A
Presotto
F
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000096:biosynthesis*; D001327:Autoimmune Diseases / Q000276:immunology; D015415:Biomarkers; D002648:Child; D002675:Child, Preschool; D003168:Complement Fixation Tests; D003165:Complement System Proteins / Q000378:metabolism; D005757:Gastritis, Atrophic / Q000175:diagnosis / Q000276:immunology*; D006801:Humans; D007070:Immunoglobulin A / Q000096:biosynthesis; D007074:Immunoglobulin G / Q000096:biosynthesis*; D008875:Middle Aged; D010295:Parietal Cells, Gastric / Q000276:immunology*
D001323:Autoantibodies; D015415:Biomarkers; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D003165:Complement System Proteins