The importance of kidney response over hematologic response in predicting kidney outcome in amyloid light-chain amyloidosis.

Abstract

Light chain amyloidosis, characterized by amyloid fibril deposition in multiple organs, often leads to progression to endstage kidney disease. This study aimed to identify predictors of kidney survival in patients with kidney amyloidosis, focusing on hematologic and kidney response. This retrospective study included 138 patients diagnosed with kidney amyloidosis between 2011 and 2019. Palladini criteria were applied to categorize kidney stage and kidney response based on initial glomerular filtration rate and proteinuria, and their changes after treatment. Hematologic response was assessed based on the 2012 International Society of Amyloidosis criteria. Deep hematologic response was defined as the achievement of at least a very good partial response. Overall, 17 (12.3%) progressed to end-stage kidney disease. Multivariable analysis, considering baseline characteristics, revealed that stage II had an increased risk of end-stage kidney disease compared to stage I (hazard ratio, 3.75; 95% confidence interval [CI], 1.38-10.15; p = 0.01). Compared to kidney response, the risk of end-stage kidney disease increased by 8.42 (95% CI, 1.72-41.35; p = 0.01) and 7.36 (95% CI, 1.25-43.33; p = 0.03) times in stable disease and kidney progression at 6 months, respectively, whereas deep hematologic response showed no association with kidney outcome. Kidney survival was longer in patients with deep hematologic response and kidney response than in those with only hematologic response (p = 0.004). The study underscores the importance of kidney response over hematologic response in predicting end-stage kidney disease and emphasizes the need to assess treatment endpoints, considering organ response alongside hematologic response.