Renal dysfunction in symptomatic Waldenström macroglobulinaemia: A nationwide Italian multicentre study

The prognostic significance of impaired renal function in Waldenström macroglobulinaemia (WM) remains poorly defined. We conducted a nationwide multicentre study to evaluate its clinical characteristics and prognostic impact in symptomatic patients. We analysed 402 symptomatic WM patients, stratified according to renal function at diagnosis (creatinine clearance <60 mL/min/1.73 m²). Renal dysfunction was identified in 119 patients (29.6%). Renal biopsy was performed in 33 cases. Patients with reduced renal function were older (median age 76 vs. 67 years, p < 0.0001), had lower haemoglobin levels (10.8 vs. 11.8 g/dL, p = 0.008) and higher 24-h proteinuria (0.29 vs. 0.20 g, p = 0.04). Comorbidities of renal interest were similarly distributed between groups. Renal dysfunction was associated with inferior median overall survival (139 vs. 203 months, p < 0.001) and progression-free survival (PFS) (80 vs. 106 months, p = 0.002). Among patients aged <70 years, renal dysfunction remained associated with shorter PFS (77 vs. 121 months, p = 0.005). Importantly, worsening renal function did not correlate with increasing age. In this setting, first-line chemoimmunotherapy was associated with improved median PFS. Thus, renal dysfunction at diagnosis may represent an underrecognized, independent adverse prognostic factor in symptomatic WM.