Light-chain amyloidosis with renal involvement: renal outcomes and validation of two renal staging systems in the Chinese population.

Background: Renal involvement is one of the most common complications of light-chain (AL) amyloidosis. For evaluating renal prognosis, two staging systems for renal involvement have been proposed, one in 2014 and one in 2017. However, the two staging systems have not yet been compared and widely used in clinic. Methods: A total of 76 patients with newly diagnosed AL amyloidosis and renal involvement proven by renal biopsy were included and followed up with an endpoint developing to dialysis. The renal outcome and two criteria were explored. Results: We confirmed the prognostic value of the 2014 renal staging system based on estimated glomerular filtration rate (eGFR) (<50 ml/min/1.73 m2) and proteinuria (>5 g/day) at diagnosis (p = 0.003). For the 2017 system, none of the patients progressed to dialysis in both stage 1 (24 h proteinuria to eGFR <30 mg/ml/min/1.73 m2) and stage 2 (24 h proteinuria to eGFR 30-99 mg/ml/min/1.73 m2). A significant difference in terms of requiring dialysis was seen only between stage 3 (24 h proteinuria to eGFR ≥100 mg/ml/min/1.73 m2) and the two other stages (p = 0.008). Conclusions: The prognostic value of the criteria based on eGFR and 24-hour proteinuria for predicting dialysis has been confirmed. These results might benefit guiding clinical treatment.