Atrophic body gastritis in patients with autoimmune thyroid disease: an underdiagnosed association.

BACKGROUND Atrophic body gastritis (ABG) has never been histologically characterized in patients with autoimmune thyroid disease (AITD), and its prevalence may be substantially different from that previously assessed based on only indirect evidence. OBJECTIVE To detect and characterize the presence of ABG in patients with AITD. METHODS Sixty-two patients with AITD (5 men and 57 women), aged between 21 and 74 years, have been screened for the presence of ABG by assaying serum gastrin levels. Patients with hypergastrinemia underwent gastroscopy followed by the histological examination of multiple biopsy specimens. The diagnosis of ABG was based on hypergastrinemia and pentagastrin-resistent achlorhydria, confirmed by histological examination. RESULTS Twenty-two (35%) of 62 patients had hypergastrinemia (mean +/- SEM gastrin level, 1070+/-288 pmol/L). The diagnosis of ABG has been histologically confirmed in all 22 patients, and the score of atrophy was moderate to severe. In group A (patients aged 20-40 years; n = 21), 6 patients (29%) had ABG, compared with 11 patients (37%) in group B (patients aged 41-60 years; n = 30) and 5 patients (45%) in group C (patients aged 61-80 years; n = 11). Antiparietal cell antibodies were detected in only 68% (15/22) of patients with ABG. Anemia was observed in 82% (18/ 22) of patients with AITD and ABG but only in 22% (9/40) of patients without ABG (P<.0001). CONCLUSIONS In the patients with AITD studied, about one third had ABG, which was diagnosed also in young patients; the measurement of gastrin levels represented the most reliable tool in the diagnosis of ABG; and the presence of anemia, even microcytic, was suggestive of undiagnosed ABG.