Serum β2-microglobulin level is associated with the survival of HIV-associated diffuse large B-cell lymphoma: a retrospective study from China

HIV-associated diffuse large B-cell lymphoma (DLBCL) is a rare type of lymphoma with poor prognosis. β2-microglobulin (β2-M) is elevated in people living with HIV, but its prognostic significance in HIV-associated DLBCL remains unclear. We retrospectively analyzed 89 HIV-associated DLBCL patients treated at Chongqing University Cancer Hospital between October 2012 and December 2023. The primary outcome was the clinical overall survival (OS) rate. The optimal cut-off value of β2-M was determined to be 5 mg/L. Compared to the low serum β2-M group (< 5 mg/L), patients in the high serum β2-M group (≥ 5 mg/L) had a higher International Prognostic Index (IPI)/ age adjusted IPI (aaIPI) score, more B symptoms, lower CD4⁺T cell counts, and higher lactate dehydrogenase (LDH) level. Patients in high group exhibited poorer OS, with 1-, 3-, and 5-year OS rates of 33.4%, 22.8%, and 18.2%, respectively. Multivariate Cox regression analysis identified serum β2-M ≥ 5 mg/L as an independent risk factor influencing OS of this patient group. Moreover, CD8⁺T cell count < 392 cells/µL, LDH ≥ 375 U/L, and non-receipt of standard treatment were also independent risk factors. Receiver operating characteristic curve analysis demonstrated that these four independent risk factors accurately predicted survival in HIV-associated DLBCL. 5 mg/L threshold for serum β2-M was associated with poor OS in HIV-associated DLBCL, indicating it could serve as a novel biomarker for assessing their prognosis.