Background: This study was planned to summarize the clinical and pathological features of renal amyloidosis in order to improve its early and accurate diagnosis.
Methods: The clinical and pathological data were analyzed from 28 patients with renal amyloidosis in the Second Xiangya Hospital from January 2005 to September 2010.
Results: Twenty seven out of the 28 (96.4%) cases were over 40 years old and presented with nephrotic syndrome. The initial diagnosis of 23 patients (82.1%) was not renal amyloidosis at their first visit to the local hospital. The pathophysiological finding included diffused deposition of amorphic and eosinophilic amyloid substance in glomerular mesangial, capillary membrane loop, interstitial, vascular, and tubular wall. 26 cases were attributed to the AL type and 2 cases to AA type. 25 patients (89.3%) were found to have monoclonal light chain in serum or urine by protein electrophoresis.
Conclusions: Renal amyloidosis is frequently neglected by local physicians in China. Renal amyloidosis should be highly suspected if the middle-aged nephrotic patient was accompanied by weight loss, organ enlargement, and monoclonal light chains in serum or urine. Renal biopsy, especially with examination under the electron microscopy, is the key to the early diagnosis of renal amyloidosis. Potassium permanganate staining and immunofluorescence examination could help to distinguish primary from secondary amyloidosis.