The Association of Kidney Function on Survival in Patients with Amyloid Light Chain Amyloidosis after Autologous Stem Cell Transplantation

Key Points. Almyloid light chain amyloid patients post autologous stem cell transplantation with higher eGFR was not associated with better progression-free survival but was associated with increased overall survival (OS). Patients with kidney amyloidosis stage 3 at baseline had inferior OS compared with those who had stage 1. OS was better in those who had complete kidney response irrespective of the baseline kidney amyloidosis stage, compared with those without response. Background. We investigated how kidney function affected progression-free survival (PFS) and overall survival (OS) after autologous stem cell transplantation (ASCT) in patients with amyloid light chain (AL) amyloidosis. Methods. We performed a retrospective cohort study of 314 patients with AL amyloidosis who underwent ASCT between 2010 and 2020. In addition to the baseline demographics, comorbidities, and kidney amyloidosis stage, eGFR and other laboratory values were collected at day 0, day 100, 6 months, 1 year, 2 years, and 3 years after ASCT. The Cox proportional hazards models were used to estimate hazard ratio (HR) based on landmark analysis for the effects of eGFR and other longitudinal measures on PFS or OS. Results. Higher eGFR values at all time points after ASCT were not significantly associated with longer PFS but was associated with increased OS. Patients with kidney amyloidosis stage 3 at baseline had inferior OS compared with those who had stage 1 (HR [95% confidence interval] = 9.428 [1.134 to 78.381], P value = 0.0379). OS was better in those who had complete kidney response irrespective of the baseline kidney amyloidosis stage, compared with those without response (HR [95% confidence interval] = 7.581 [2.042 to 28.149], P = 0.0025). Conclusions. This retrospective study shows that kidney function has an effect on survival in patients with AL amyloidosis who undergo ASCT. Both higher eGFR at baseline and complete kidney response after ASCT favor improved survival outcomes.