Primary amyloidosis--involving principally intrarenal blood vessels.

We analysed renal biopsies from 34 nephrotic patients with renal amyloidosis, seven with primary form kappa chain (AL amyloidosis) and 27 with secondary amyloidosis associated with the other chronic diseases. Renal biopsy specimens were analysed using optical and immunofluorescence microscopy. The extent of amyloid deposits was graded from 0 to + + + +. Intrarenal blood vessel deposits were more prominent than intraglomerular in five of seven patients with AL amyloidosis, while they were identical in one, and in one, intraglomerular amyloid deposits were dominant. The results were different in the group of patients with secondary amyloidosis: a lower degree of intrarenal blood vessels deposition than glomerular was noted in 22 of 27 cases, the degree of deposition was identical in 4 of 27 cases and more expressed blood vessel deposition was present in only one case. Granular or combined deposits (granular+linear) were found on immunofluorescence microscopy in primary form, but the dominant form of deposition was amorphous in secondary amyloid.