Clinical and laboratory profile of renal amyloidosis: A single-center experience

Abstract

The kidney is the most common organ involved in systemic amyloidosis. We aimed to study etiology and clinicopathological profile of renal amyloidosis. This was a retrospective study of 40 consecutive adult patients with biopsy-proven renal amyloidosis evaluated over a period of two years. Emphasis was given to describing the clinical presentation, renal function, proteinuria, type of amyloidosis, and its etiology. Mean age of the study cohort was 44 ± 15 years (with a male-to-female ratio of 3:1). Amyloid A (AA) amyloidosis was the most common type of amyloidosis observed in 72.5% of cases. Amyloid light chain (AL) amyloidosis accounted for 17.5% of cases, and the rest remained undetermined. AA amyloidosis had widespread age distribution while AL amyloidosis was confined to those >40 years. Proteinuria was the most common renal manifestation observed in all patients. Nephrotic syndrome was seen in 70% of patients. Mean 24 h proteinuria was 6.4 g. Renal failure was the second most common manifestation seen in 70% of patients, of whom 21.4% required hemodialysis. Tuberculosis (TB) accounted for 90% cases of AA amyloidosis. The most prevalent form was pulmonary TB while the rest accounted for by rheumatoid arthritis and bronchiectasis. Among patients with TB induced amyloidosis, 61.5% had received adequate treatment for TB in the past. All patients with AL amyloidosis had nephrotic range proteinuria, five had renal failure out of which two required dialysis. Cardiac involvement was seen in two patients. AA amyloidosis was the most common type of renal amyloidosis in the present study and pulmonary TB was the most common etiology.