Clinicopathological analysis of primary central nervous system lymphoma in patients with or without HIV infection

Abstract

Background The main aim of this study was to investigate the differences in clinicopathological features between HIV-related primary central nervous system lymphoma (PCNSL) and immunocompetent-primary central nervous system lymphoma (IC-PCNSL). Methods The study included thirty-seven patients with HIV-related PCNSL and thirty patients with IC-PCNSL. Hematoxylin & eosin (HE) staining, immunohistochemical detection using CD20, Bcl-2, Bcl-6, p53, C-MYC, Ki67, methyltransferase like factor 3 (METTL3) antibodies, and Epstein–Barr encoding region (EBER) in situ hybridization were performed. Results All of the patients were classified as the diffuse large B-cell lymphoma (DLBCL) histological type. Patients with HIV-related PCNSL were younger and more likely to be male compared to patients with IC-PCNSL. Elevated lactate dehydrogenase (LDH) and low sugar content in cerebrospinal fluid (CSF) were more common among HIV-related PCNSL. The expression levels of METTL3, Bcl-2 and p53 were significantly higher in HIV-related PCNSL patients than in IC-PCNSL patients. In contrast, HIV-related PCNSL patients exhibited lower levels of Bcl-6 expression and more likely to be positive for EBER, accounting for 81.1% of these patients. Furthermore, we also found that the expression of METTL3 was lower in germinal center B (GCB)-like DLBCL (n = 7) than in activated B-cell (ABC)-like DLBCL (n = 32) in HIV-related PCNSL (p = 0.041); however, in IC-PCNSL patients, the expression of METTL3 was not significantly different between GCB-like DLBCL and ABC-like DLBCL (p = 0.710). Conclusion Our study of Chinese patients with HIV-related PCNSL and IC-PCNSL has revealed new findings: although the tumor manifestations are similar in PCNSL patients with and without HIV, HIV-related PCNSL differs from IC-PCNSL in terms of pathological characteristics including METTL3, Bcl-2, p53, Bcl-6, and EBER. We therefore suggest that the pathogenesis of HIV-related PCNSL and IC-PCNSL may be different due to host's immune status.