Beta2-microglobulin is a valuable marker and identifies a poor-prognosis subgroup among intermediate-risk patients with diffuse large B cell lymphoma.

Prognosis of diffuse large B cell lymphoma (DLBCL) can be predicted by various factors. The most widely used tool for prediction is the international prognostic index (IPI). β2-microglobulin is a tumor marker commonly used in hematological malignancies. β2-microglobulin is well correlated with outcome of DLBCL. It has been used as an adjunctive tool in some scoring systems for prognostication of DLBCL. In this study, we collected data of patients with diagnosis of DLBCL between 2015 and 2019 in our institute. For each patient, IPI was calculated according to published literature. At diagnosis, serum levels of β2-microglobulin were measured in the clinical laboratory and the results were retrieved from medical records. A total of 516 patients (269 male and 247 female) were enrolled for retrospective analysis. The median age was 64 (range 22-96). The median follow-up period was 32.2 months. The median level of β2-microglobulin was 2319 μg/L (normal range < 2366 μg/L in the clinical laboratory). Level of β2-microglobulin was significantly different between survivors and patients who succumbed to the disease. β2-microglobulin level was correlated with tumor stage, extranodal involvement, B symptoms and IPI, suggesting that it may be a good surrogate marker for disease severity and outcome prediction. We selected the intermediate-risk patients for further analysis. Patients with intermediate-risk IPI and high β2-microglobulin levels have overall survival comparable to patients with high-risk IPI, suggesting an important role of β2-microglobulin in subdivision of DLBCL patients. In conclusion, β2-microglobulin levels correlated with outcome of DLBCL. It may be used independently as a prognostic factor. Subdivision of patients with intermediate-risk IPI may identify a group of high-risk patients, which can be helpful in refining plans of treatment and follow-up.