アミロイドーシスにおける糸球体内アミロイド沈着様式，アミロイド蛋白および臨床症状の関係

Abstract

In order to elucidate the relationship of renal pathology to chemical types of amyloid protein and clinical features, 63 autopsy cases of renal amyloidosis were studied. Using plastic embedded sections, glomerular amyloid deposition was divided on the basis of morphological characteristics, into the following 4 types : mesangial nodular type showing nodular amyloid deposition in the mesangium with sparse involvement of the capillary wall (25 cases) ; mesangio-capillary type revealing diffuse amyloid deposits in the mesangium as well as along both sides of the capillary wall (20 cases) ; perimembranous type principally involving the subepithelial aspect of the capillary wall in which exuberant spicular formation is invariably observed (7 cases) ; and hilar type showing amyloid deposits almost exclusively in hilar arterioles (11 cases). Twenty-four of 25 cases of the mesangial nodular type (96%) showed deposition of AA protein. However, mesangio-capillary and perimembranous types were associated with deposition of AL protein in 16 of 20 (80%) and all 7 cases, respectively. In the hilar type, AA protein was observed in 8 of 11 cases (73%). Nephrotic syndrome was more frequent in patients with AL amyloidosis in which amyloid commonly involved the capillary wall ; notably, all patients with the perimembranous type doveloped nephrotic syndrome irrespective of the extent of glomerular amyloid deposits. Chronic renal failure and renal death appeared more commonly in the mesangial nodular type in which the extent of glomerular amyloid deposits correlated not only with serum creatinine levels but also with that of vascular amyloid deposits. The results obtained suggest that the chemical type of amyloid protein (AA vs AL) is associated with significant differences in the morphological, clinical and prognostic features of renal involvement in amyloidosis.