Clonal hematopoiesis is associated with increased risk of progression of asymptomatic Waldenström macroglobulinemia.

Clonal hematopoiesis (CH) is associated with adverse outcomes in patients with non-Hodgkin lymphoma (NHL) and multiple myeloma undergoing autologous stem cell transplantation. Still, its implications for patients with indolent NHL have not been well studied. We report the prevalence of CH in patients with Waldenström macroglobulinemia (WM) and its association with clinical outcomes. To unambiguously differentiate CH mutations from those in the WM clone, CH was defined by the presence of somatic mutations in DNMT3A, TET2, or ASXL1 (DTA) and was detected in 14% of 587 patients with IgM monoclonal gammopathy of undetermined significance (MGUS), smoldering WM (SWM) or WM. The presence and size of DTA clones were associated with older age. Patients with CH had an increased risk of progression from MGUS or SWM to WM, but not worse overall survival in this cohort. These findings further illuminate the clinical effects of CH in patients with indolent NHL such as WM.