Abstract:Objective To investigate the clinical characteristics of indolent B-cell non-Hodgkin lymphoma (iB-NHL) with monoclonal immunoglobulin (McIg). Methods The clinical and pathological data of 82 newly diagnosed iB-NHL patients in the Affiliated Hospital of Nantong University from November 2013 to October 2021 were retrospectively analyzed. According to the results of serum immunofixation electrophoresis (SIFE), they were divided into McIg positive group (30 cases) and negative group (52 cases). The clinical characteristics, laboratory examination results and overall survival (OS) were analyzed. Results iB-NHL with McIg were more common in males, with IgM-κ being the most common, and the clinical stage was mostly stage Ⅲ-Ⅳ, with marginal zone lymphoma (MZL) as the main stage. Compared with the negative group, patients in the positive group were more likely to have bone marrow infiltration, international prognostic index (IPI)≥3, decreased white blood cell count, anemia, hypoalbuminemia, elevated globulin and cystatin C (P＜0.05). Cox univariate analysis showed that IPI≥3 and McIg positivity were associated with worse OS in patients. Multivariate analysis showed that McIg positivity was an independent adverse prognostic factor for OS of patients (HR=0.074, 95%CI: 0.009-0.609, P=0.015). Follow-up ended on October 31, 2021. The median OS of the positive group was 52 months, but the median OS of the patients without McIg was not reached, and the difference of OS between two groups had statistical significance (P＜0.01). Conclusion Among the newly diagnosed patients with iB-NHL, the prognosis of patients with McIg is relatively poor, which needs to be paid more attention in clinical diagnosis and treatment.