BACKGROUND: This study investigated the predictive value of β2-microglobulin (β2-MG) on the prognosis of diffuse large B-cell lymphoma (DLBCL) patients. METHODS: Patients with DLBCL diagnosed by pathologic biopsy were collected from January 2021 through December 2022, and a total of 98 patients were finally included. The 98 patients were grouped according to their prognosis, i.e., into the survival group (n = 69) and death group (n = 29). The critical value of β2-MG for survival in DLBCL patients was obtained by ROC curve. Kaplan Meier curve was plotted to analyze the relationship between β2-MG and the overall survival of DLBCL patients, and a one-way test was performed to examine the clinical data of the patients. Independent predictors affecting the prognosis of DLBCL patients were screened using unifactorial and multifactorial Cox regression analysis. R 4.2.1 software was used to refit the constructed column-line graph prediction model and internal validation. RESULTS: The critical value of β2-MG for survival in DLBCL patients was 3.285 µg/L, obtained by ROC curve. All patients were categorized into the following two groups: β2-MG ≤ 3.285 group (n = 75) and β2-MG >
3.285 group (n = 23). During the follow-up period, 9 endpoint events occurred in the β2-MG ≤ 3.285 group and 20 endpoint events occurred in the β2-MG >
3.285 group. The β2-MG ≤ 3.285 group had a higher overall survival rate than the β2-MG >
3.285 group. High levels of β2-MG, LDH, and CRP were independent prognostic influences affecting overall survival in DLBCL patients. β2-MG, LDH, and CRP were combined to construct the prognostic prediction model, and there was a better consistency between the predicted probability and the actual results. CONCLUSIONS: Poor treatment prognosis of DLBCL patients is closely related to abnormally elevated levels of β2-MG. High levels of β2-MG, LDH, and CRP are independent risk factors for disease progression and prognostic survival in DLBCL patients.