Primary Amyloidosis

Great progress has been made in defining the structure of amyloid. Further studies of the ultrastructure and composition of amyloid are described. Clinical and immunochemical studies on 15 patients with primary amyloidosis are presented. These studies do not support a direct relation between immunoglobulins, particularly Bence Jones proteins, and amyloidosis. Low immunoglobulin levels in these patients were frequently noted and reflected decreased synthesis, urinary or gastrointestinal loss, or all of these. Peripheral vascular blood flow was measured in several patients, two of whom suffered from intermittent claudication. Both of these patients had a decreased vasodilator response to ischemia and exercise apparently due to extensive vascular amyloid. On the basis of studies presented here and other recent studies, an alternate hypothesis for the pathogenesis of primary amyloidosis is presented.