Objective: Although rare, renal amyloidosis is an important diagnosis that bares a significant morbidity and mortality. The purpose of this study was to present current single center experience in the past 28 years.
Methods: A total of 6151 kidney biopsies were performed in our hospital from Jan. 1983 to Dec. 2010; 5844 were native kidney biopsies. Cases with a diagnosis of renal amyloidosis were identified through a search of our data bank and the clinical data were retrieved from medical charts. The patients were further classified as AL type and non-AL type. The trend of incidence was analyzed and the clinical features were compared. Risk factors that predict patient mortality were discovered by logistic regression analysis.
Results: Forty out of 5844 native kidney biopsies (0.68%) were identified as renal amyloidosis. Eighteen (45%) were of AL type. The mean age at diagnosis was 62.6 ± 13.4 years. Male was the predominant gender that was involved. Clinically, most (80%) have nephrotic range proteinuria (mean 24 hours urine protein: 6.9 ± 4.7 g). With a mean follow-up duration of 1155 day, the 1-year and 5-year patient survival were 42.9% and 17.9%, respectively. eGFR at biopsy was the sole predictive factor for patient survival.
Conclusion: Senile patients with nephrotic syndrome should elicit the suspicion of renal amyloidosis. The incidence appeared to be increasing and the prognosis poor.