Primary Amyloidosis With Renal Involvement: Outcomes in 77 Consecutive Patients at a Single Center.

BACKGROUND: Outcomes in primary amyloid renal patients are of interest as the era of monoclonal antibody therapies begins.

PATIENTS AND METHODS: We studied 77 consecutive primary amyloid renal patients (58% men) for renal progression (end stage renal disease [ESRD]), renal response (RR), and overall survival (OS).

RESULTS: At diagnosis median age was 63 (range, 35-81) years, estimated glomerular filtration rate 70 mL/min (range, 5-114), difference between involved and uninvolved free light chains 127 mg/L (range, 1-9957), ESRD 4%, renal stage 2 and 3 78%, and cardiac stage 2 and 3 56%. Ninety-six percent received bortezomib and 44% stem cell transplantation as well as bortezomib, 68% achieved complete or very good partial hematologic response (CR/VGPR), 34% had ESRD, and 39% RR. Median times to ESRD and RR were 18 (range, 3-81) and 12 (range, 2-30) months, respectively. Median OS was not reached in this cohort and was not reached from onset of ESRD. More than two-thirds of patients with ESRD also achieved CR/VGPR. In those without ESRD at diagnosis, baseline creatinine and absent RR predicted progression to ESRD in multivariate Cox regression analysis, whereas CR/VGPR predicted RR. In multivariate Cox regression analysis, cardiac stage and achievement of CR/VGPR predicted OS, enabling construction of a prognostic model.

CONCLUSION: Anti-plasma cell therapies provide a definite albeit limited benefit and new approaches to amyloid-related organ dysfunction are needed.