Doenças renais em pacientes idosos submetidos à biópsia percutânea de rins nativos

INTRODUCTION: The elderly population is growing and aging in better clinical conditions than in the past. However, the distribution and course of kidney diseases in elderly patients are not well known partially due to reluctance to indicate renal biopsies in those patients. OBJECTIVE: To evaluate the distribution, clinical features, and outcomes of nephropathies diagnosed by biopsy in the elderly. PATIENTS AND METHODS: Seventyone patients (47 males, 24 females) aged 60 years or older (67.3 ± 6.5 years), undergoing biopsy from January 1990 to December 2006, were evaluated. They were grouped according to their clinical syndromes. RESULTS: Nephrotic syndrome was observed in 35 patients (49.3%), mainly associated with membranous nephropathy (17 patients), followed by amyloidosis and focal segmental glomerulosclerosis (seven patients each). Acute kidney injury (AKI) was diagnosed in 19 patients, and the main histopathological diagnoses were acute tubular necrosis (six patients) and cast nephropathy (three patients). Of those 19 patients, only two had a favorable course, while the others died early or progressed toward advanced chronic kidney disease. Twelve patients undergoing biopsy because of asymptomatic hematuria or proteinuria had different diagnoses, but most of them already had significant chronic nephropathy. In five patients with nephritic syndrome, the biopsies also showed several diagnoses. CONCLUSIONS: Nephrotic syndrome was the major indication for renal biopsy, and membranous nephropathy was the most frequent diagnosis. Among patients with AKI and asymptomatic hematuria or proteinuria, different diagnoses were found with high levels of advanced chronic nephropathy.