Impact of Qualitative and Quantitative Immunoparesis on Early Infection Risk in Patients with Newly Diagnosed Multiple Myeloma.

Background: This study explores the impact of different immunoparesis states on early infection risk within 6 months of diagnosis in patients with newly diagnosed multiple myeloma (NDMM), aiming to inform clinical infection prevention strategies. Methods: A retrospective analysis was conducted on 213 NDMM patients (2016-2024). Immunoparesis was classified qualitatively (no, partial, and full immunoparesis) and quantitatively (with immunoglobulin reduction < 50% and ≥ 50%). Early infection rates and immunoparesis status were assessed using Kaplan-Meier survival curves. Cox regression models were applied to evaluate the independent prognostic effect of immunoparesis on infection risk. Results: Immunoparesis significantly increased the risk of early infections. In the qualitative analysis, infection rates were 15.8% for no immunoparesis, 53.1% for partial, and 53.8% for full immunoparesis (Log-rank P = 0.017). In the quantitative analysis, infection rates were 51.9% for < 50% immunosuppression and 54.2% for ≥ 50% immunosuppression, compared to 15.8% for no immunoparesis (Log-rank P = 0.017). Cox regression analysis showed that partial and full immunoparesis increased the risk of infection by 8.9-fold (HR = 8.9, P = 0.004) and 7.8-fold (HR = 7.8, P = 0.006), respectively. Similarly, < 50% and ≥ 50% immunosuppression increased infection risk by 8.67-fold (HR = 8.67, P = 0.005) and 7.95-fold (HR = 7.95, P = 0.005), respectively. Conclusion: Immunoparesis significantly increases early infection risk in NDMM patients. However, no significant risk gradient was observed relative to the breadth or depth of immunoparesis within this cohort. Monitoring and timely intervention for immunoparesis are essential for infection prevention.