Anti-brush border antibodies (ABBA) in Crohn's disease.

Seventy-four serum samples from patients with Crohn's disease were analysed for the presence of antibodies against various tissue antigens. With indirect immunofluorescence microscopy 61% of the patient sera were shown to possess antibodies (in a titre of 1:25 or more) reacting with rat brush border membrane antigens in the proximal tubules of the kidneys, in the gastric parietal cells, and in the bile canaliculi of the liver. Serum samples submitted for routine IF autoantibody-screening served as controls; 10% of these sera contained anti-brush border antibodies.