Clinical characteristics of the patients with systemic amyloidosis in 2000-2010

Abstract

Background: The epidemiology of systemic amyloidosis has been changing in the last decades. We aim to describe the clinical characteristics of the patients seen at our institution with systemic amyloidosis in 2000-2010 and compare them with previous Spanish series.

Patients and methods: An observational, retrospective study was performed on all patients admitted to a tertiary hospital in Madrid, Spain who had been diagnosed of amyloidosis from January 2000 to December 2010. Patients without a proven diagnosis of amyloidosis, with dialysis-associated, senile, or localized forms of amyloidosis were excluded from the study. A systematic review was made of the clinical records, collecting the demographic, clinical and biochemical variables at diagnosis and patients' outcome.

Results: A total of 55 patients were studied, 24 (44%) of whom had AL amyloidosis, 30 (56%) AA amyloidosis, and 1 a familiar form. The most frequent underlying disorders were rheumatoid arthritis (9 patients, 30%) and ankylosing spondylitis (4 cases, 13%). The kidneys were the most frequently involved organ (36 patients, 67%) with nephrotic-range proteinuria at diagnosis (3.4 ± 3.7 g/24 h). Median time to diagnosis was 3 months (interquartile range [IQR]: 1-17). Median follow-up time was 24 months (IQR: 10-91). During follow-up 31 patients died; 18 of those deaths were related to amyloidosis.

Conclusions: Renal dysfunction dominates the course of systemic amyloidosis, which does not seem to have changed in the last decades. We have observed an important delay in the diagnosis of these processes. Therefore, it is necessary to maintain a high degree of clinical suspicion regarding these conditions.