Prognostic Significance of Paraproteinemia in Marginal Zone Lymphoma

The prognostic significance of paraproteinemia in marginal zone lymphoma (MZL) is underexplored. We aimed to investigate the clinical and biological impact of paraproteinemia and its association with survival outcomes in patients with MZL. We retrospectively evaluated 73 patients diagnosed with MZL between 2000 and 2022 at a single center. Baseline clinical characteristics and survival outcomes were compared according to paraproteinemia status. Paraproteinemia was present in 27.3% (20/73) of patients, predominantly of the IgM subtype. Paraproteinemia was significantly associated with older age (p<0.001), advanced disease stage (p=0.023), elevated β2-microglobulin (p=0.001), bone marrow involvement (p=0.026), and lower hemoglobin (p=0.002) and albumin levels (p<0.001). Patients with paraproteinemia had significantly shorter overall survival (OS) and progression-free survival (PFS) compared to those without paraproteinemia (mean OS: 73.8 vs. 178.8 months, p=0.046; mean PFS: 63.5 vs. 159.7 months, p=0.049). The negative prognostic impact was more pronounced among patients with IgM paraproteinemia (OS: 58.8 vs. 178.2 months, p=0.006; PFS: 45.2 vs. 157.4 months, p=0.004). In histologic subtypes analysis, only MALT lymphoma patients with IgM paraproteinemia showed significantly shorter OS (70.5 vs. 152.6 months, p=0.010). Patients with IgM paraproteinemia treated with R-CHOP-like regimens experienced significantly shorter PFS and OS. Paraproteinemia, particularly of the IgM subtype, is associated with adverse clinical and biological features and predicts inferior survival in patients with MZL. Evaluating paraproteinemia status at diagnosis as a potential prognostic marker may guide treatment strategies. Prospective studies are needed to confirm the prognostic utility of paraproteinemia and support its incorporation into MZL treatment management.