Morphological, immunohistological and clinical findings in renal amyloidosis: correlations with prognosis in 16 patients.

Sixteen patients affected by renal amyloidosis (A.) and submitted to renal biopsy have been studied by light microscopy and immunofluorescence. Clinical manifestations at observation and follow up have been reviewed. Survival was 32% at ten years, lower than all other nephropathies except rapidly-progressive glomerulonephritis. Primary A. had a significantly worse survival rate than secondary A. An observation up to 6 years after biopsy allowed us to isolate a group of patients with a steady good renal function: this group is characterized by: a longer mean duration of nephropathy before observation, a lower incidence of nephrotic syndrome (NS), absence of renal failure at time of biopsy, a higher incidence of increased mesangial areas at light microscopy, a lower percentage of glomerular capillary walls thickening, a higher incidence of amyloid deposits on vessels but not on glomerular capillaries, a definite more elevated presence of Ig and C3 over mesangium and glomerular capillary walls. The possible role of the last findings is discussed.