Aminopyrine breath test. Prospective comparison with liver histology and liver chemistry tests following jejunoileal bypass performed for refractory obesity.

To determine whether the aminopyrine breath test reflects the presence of increased pericentral fibrosis, steatonecrosis, and cirrhosis following jejunoileal bypass, 21 patients were evaluated with liver biopsies, liver chemistry tests, 45-min bromosulfothalein retention tests, and aminopyrine breath tests prior to bypass and at 3, 6, and 12 months thereafter. Following bypass, 15 biopsies demonstrated increased pericentral fibrosis, steatonecrosis, or cirrhosis, and 35 biopsies revealed increased fatty infiltration alone. Although the aminopyrine breath test results were significantly lower in patients with increased pericentral fibrosis, steatonecrosis, and cirrhosis at 6 and 12 months following bypass (P less than 0.05), this test had a positive predictability of only 0.67. An abnormal AST had a positive predictability of 0.87. Other liver function tests were less reliable in identifying patients with potentially progressive lesions following bypass. Thus, the AST is more useful than the aminopyrine breath test in reflecting increased pericentral fibrosis, steatonecrosis, and cirrhosis following jejunoileal bypass. The nonspecific effects of obesity and increased fatty infiltration of the liver following jejunoileal bypass may account for the low predictability of the aminopyrine breath test.