Renal disease related to Waldenstrom macroglobulinaemia: incidence, pathology and clinical outcomes

The incidence and prognostic impact of nephropathy related to Waldenstrom macroglobulinaemia (WM) is currently unknown. We performed a retrospective study to assess biopsy-confirmed WM-related nephropathy in a cohort of 1391 WM patients seen at a single academic institution. A total of 44 cases were identified, the estimated cumulative incidence was 51% at 15years. There was a wide variation in kidney pathology, some directly related to the WM: amyloidosis (n=11, 25%), monoclonal-IgM deposition disease/cryoglobulinaemia (n=10, 23%), lymphoplasmacytic lymphoma infiltration (n=8, 18%), light-chain deposition disease (n=4, 9%) and light-chain cast nephropathy (n=4, 9%), and some probably related to the WM: thrombotic microangiopathy (TMA) (n=3, 7%), minimal change disease (n=2, 5%), membranous nephropathy (n=1, 2%) and crystal-storing tubulopathy (n=1, 2%). The median overall survival in patients with biopsy-confirmed WM-related nephropathy was 115years, shorter than for the rest of the cohort (16years, P=003). Survival was better in patients with stable or improved renal function after treatment (P=005). Based on these findings, monitoring for renal disease in WM patients should be considered and a kidney biopsy pursued in those presenting with otherwise unexplained renal failure and/or nephrotic syndrome.