Ebv-Positive Hiv-Associated Diffuse Large B Cell Lymphomas Are Characterized By Jak/Stat (Stat3) Pathway Mutations And Unique Clinicopathologic Features

Even in the era of highly active combination antiretroviral therapy (cART), patients with HIV have a disproportionate risk of developing aggressive lymphomas that are frequently Epstein-Barr virus (EBV)-related. Here, we investigate HIV-associated diffuse large B-cell lymphoma (HIV-DLBCL) and compare EBV-positive and EBV-negative cases. HIV-DLBCL were identified from two academic medical centres and characterised by immunohistochemistry, EBV status, fluorescence in situ hybridisation, cell of origin determination by gene expression profiling, and targeted deep sequencing using a custom mutation panel of 334 genes. We also applied the Lymphgen tool to determine the genetic subtype of each case. Thirty HIV-DLBCL were identified, with a median patient age of 46 years and male predominance (5:1). Thirteen cases (48%) were EBV-positive and 14 (52%) EBV-negative. Nine of the 16 tested cases (56%) had MYC rearrangement, three (19%) had BCL6 (two of which were double hit MYC/BCL6) and none had BCL2 rearrangements. Using the Lymphgen tool, half of the cases (15) were classified as other. All HIV-DLBCL showed mutational abnormalities, the most frequent being TP53 (37%), MYC (30%), STAT3 (27%), HIST1H1E (23%), EP300 (20%), TET2 (20%), SOCS1 (17%) and SGK1 (17%). EBV-negative cases were mostly of germinal centre B-cell (GCB) origin (62%), showed more frequent mutations per case (a median of 13 center dot 5/case) and significant enrichment of TP53 (57% vs. 15%; P = 0 center dot 046), SGK1 (36% vs. 0%; P = 0 center dot 04), EP300 (43% vs. 0%; P = 0 center dot 02) and histone-modifying gene (e.g. HIST1H1E, HIST1H1D, 79% vs. 31%; P = 0 center dot 02) mutations. EBV-positive cases were mostly of non-GCB origin (70%), with fewer mutations per case (median 8/case; P = 0 center dot 007), and these tumours were enriched for STAT3 mutations (P = 0 center dot 10). EBV-positive cases had a higher frequency of MYC mutations but the difference was not significant (36% vs. 15%; P = 0 center dot 38). EBV-association was more frequent in HIV-DLBCLs, arising in patients with lower CD4 counts at diagnosis (median 46 center dot 5 vs. 101, P = 0 center dot 018). In the era of cART, approximately half of HIV-DLBCL are EBV-related. HIV-DLBCL are enriched for MYC rearrangements, MYC mutations and generally lack BCL2 rearrangements, regardless of EBV status. Among HIV-DLBCL, tumours that are EBV-negative and EBV-positive appear to have important differences, the latter arising in context of lower CD4 count, showing frequent non-GCB origin, lower mutation burden and recurrent STAT3 mutations.