Outcome of 121 patients with renal amyloid a amyloidosis

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.