198 - Diagnostic efficacy of a specific serological profile for the diagnosis of chronic autoimmune gastritis
Autor(s): A. Antico, R. Tozzoli, D. Villalta, E. Tonutti, M. Tampoia, N. Bizzaro
Issue: RIMeL - IJLaM, Vol. 6, N. 3, 2010 (MAF Servizi srl ed.)
Page(s): 198-204
Summary
Background. This study aimed to evaluate the diagnostic accuracy of a serological profile for the diagnosis of autoimmune gastritis (AIG) by combining the detection of anti-parietal-cell antibodies (PCA), anti-intrinsic-factor antibodies (IFA), anti-Helicobacter pylori (Hp) antibodies, and measurement of blood gastrin. Methods. We studied 181 consecutive patients (aged 25-81) with anemia (Hb<10 mg/dl) caused by iron orvitamin B12 deficiency. PCA, IFA, and anti-Hp anti-bodies were assayed by quantitative ELISA, and gastrinemia was measured by an immunoenzymatic che-miluminescent method. Results. PCA were positive in 83/181 (45.9%) patients (14 of these also had IFA). Gastrinemia was notably high (>115 pg/mL) only in 44 PCA-positive patients and in none of the PCA-negative subjects. All 83 PCA-positive and 11 PCA-negative patients were subjected to gastroscopy. Histological and serological findings led to classifying patients in to four groups. Group 1) 30 (36%) patients diagnosed with AIG whowere PCA-positive and had hypergastrinemia. Group 2) 14 (17%) patients diagnosed with gastric atrophy who had positive PCA and IFA antibodies, and hyper-gastrinemia; Group 3) 18 (22%) patients with nonspecific lymphocytic gastritis who were PCA-positive, had normal gastrinemia, and in whom IFA were absent. Group 4) 21 (25%) PCA-positive and IFA-negative patients who had anti-Hp antibodies and normal gastrinemia, and who were affected by Hp multifocal atrophic gastritis. The 11 seronegative individuals had normal gastrin levels and a histological pattern compatible with superficial gastritis. Conclusions. The “serological biopsy” (PCA, IFA, anti-Hp antibodies and gastrinemia) has a high predictive value for AIG and may be used as a diagnostic laboratory profile in patients with iron-deficient anemia re-fractory to oral iron treatment, and in patients with vitamin B12-dependent anemia.
Key-words: autoimmune gastritis, parietal cell antibodies,intrinsic factor antibodies, Helicobacter pylori antibodies, gastrin, histology.