Characterization and outcomes of renal leukocyte chemotactic factor 2-associated amyloidosis

Abstract

Amyloidosis derived from leukocyte chemotactic factor 2 (ALECT2) is a recently described disease. Here, we report the characteristics and outcome of 72 patients with renal ALECT2, which included 19 who had another kidney disease on biopsy. Ninety-two percent of patients were Hispanics and over half were elderly. Three had other organ, but not cardiac, amyloidosis involvement. All patients without concurrent disease, except three, presented with chronic renal insufficiency. Proteinuria was variable and absent in a third, whereas nephrotic syndrome and hematuria were rare. After a median follow-up of 26 months, one-third developed end-stage renal disease (ESRD). The median renal survival was 62 months. Independent predictors of renal survival were serum creatinine at diagnosis, with a value of 2.0 mg/dl being the best cutoff for predicting ESRD, percentage global glomerulosclerosis, and presence of diabetes. Only four patients died and four had received chemotherapy for an erroneous diagnosis of immunoglobulin light chain-derived amyloidosis. Five patients underwent kidney transplantation; none had graft loss but one had disease recurrence. Patient survival is superior to renal immunoglobulin light chain-derived amyloidosis and reactive amyloidosis largely due to the absence of cardiac involvement. Thus, renal ALECT2 mainly affects elderly Hispanics who typically present with chronic renal insufficiency and bland urine sediment, with or without proteinuria.