Background: Amyloid A (AA) amyloidosis is a multisystem, progressive and fatal disease. Renal involvement occurs early in the course of AA. We aimed to investigate the etiology, clinical and laboratory features, and outcome of patients with biopsy-proven renal AA amyloidosis.
Materials and methods: A total of 121 patients (male/female: 84/37, mean age 42.6 ± 14.4 years) were analyzed retrospectively between January of 2001 and May of 2013. Demographic, clinical and laboratory features and outcomes data were obtained from follow-up charts.
Results: Familial Mediterranean fever (37.2%) and tuberculosis (24.8%) were the most frequent causes of amyloidosis. Mean serum creatinine and proteinuria at diagnosis were 2.3 ± 2.1 mg/dL and 6.7 ± 5.3 g/day, respectively. Sixty-eight (56.2%) patients were started dialysis treatment during the follow-up period. Mean duration of renal survival was 64.7 ± 6.3 months. Age, serum creatinine and albumin levels were found as predictors of end-stage renal disease. Fifty patients (%41.3) died during the follow-up period. The mean survival of patients was 88.7 ± 7.8 months (median: 63 ± 13.9). 1, 2 and 5 years survival rates of patients were 80.7%, 68.2% and 51.3%, respectively. Older age, male gender, lower levels of body mass index, estimated glomerular filtration rate, serum albumin, calcium, and higher levels of phosphor, intact parathyroid hormone and proteinuria were associated with a higher mortality. Higher serum creatinine, lower albumin, dialysis requirement and short time to dialysis were predictors of mortality.
Conclusion: The outcome of patients with AA amyloidosis and renal involvement is poor, particularly in those who had massive proteinuria, severe hypoalbuminemia and dialysis requirement at the outset.
Keywords: Amyloid A amyloidosis; dialysis; end-stage renal disease; survival.