Association between clinical characteristics and AL amyloid deposition in the kidney

Renal involvement is very common in AL amyloidosis. Our aim was to investigate associations between the clinical characteristics and renal pathology of patients with AL amyloidosis. The data of 11 adult Japanese patients with AL amyloidosis and renal involvement were analyzed retrospectively. To assess the difference based on the pattern of distribution of amyloid deposition, we divided the patients into a group with the capillary form and a group with the small vessel form, and compared the clinical characteristics of the two groups. Concerning AL amyloidosis, the small vessel form group was associated with cardiac involvement and left ventricular thickening compared with the capillary form group (p = 0.03). There were no significant differences between the groups in the rates of patient survival and renal survival. There was a negative correlation between grade of amyloid deposition and renal survival duration (p = 0.04, r² = 0.66). The degree of amyloid deposition was not correlated with the extent of proteinuria or renal function. These findings suggest that the vascular deposition pattern of amyloid in the kidney is important for determining patient survival and renal outcome.