AA amyloid quantification in biopsy samples from the stomach.

Amyloidosis is usually diagnosed through the histological examination of biopsy samples. However, its quantitative evaluation can be difficult. In this study, we immunochemically measured amyloid A (AA) proteins in biopsy samples taken from the stomachs of patients with AA amyloidosis. Samples were treated with guanidine and were subjected to an enzyme immunoassay for serum amyloid A. The results were compared with histological findings. All patients who tested negative for amyloid deposits had low values that clearly distinguished them from amyloid-positive patients. Among the amyloid-positive patients, the AA values correlated significantly with histological findings. This method may be useful for the quantitative evaluation of AA amyloidosis.