AB-IPI: A Clinicopathological Prognostic Score Integrating Host Fitness and Tumor Biology in Diffuse Large B-Cell Lymphoma

The introduction of rituximab has eroded the discriminatory power of the International Prognostic Index (IPI) in diffuse large B-cell lymphoma (DLBCL), necessitating refined risk stratification. To address this, we developed the AB-IPI, a prognostic tool integrating tumor burden with host inflammation and biological resistance. In a retrospective analysis of 289 patients treated with R-CHOP-like immunochemotherapy, multivariate Cox regression identified IPI score > 2, serum albumin < 3.6 g/dL, and BCL2 protein expression > 50% as independent prognostic factors for overall survival. The AB-IPI stratified patients into four risk groups with 5-year survival rates ranging from 88.0% (Low) to 29.0% (High) (P < 0.0001). Crucially, the AB-IPI demonstrated superior discrimination (C-index: 0.725 vs. 0.702) and calibration compared to the standard IPI, with Decision Curve Analysis confirming greater net benefit. By capturing the triad of tumor burden, host fitness, and tumor biology using universally accessible biomarkers, the AB-IPI offers a robust, practical alternative for identifying high-risk patients in the rituximab era.