Abstract 993: Epigenetic immune cell profiling in B-non-Hodgkin lymphoma biopsies

Abstract

Early detection and differential diagnosis of Non-Hodgkin lymphoma (NHL) is essential for the initiation of suitable therapy options. Biopsy based diagnosis allows allocation to World Health Organization (WHO) sub-classification groups but prognosis often needs identification of specific genetic aberrations or gene expression patterns. Despite this strategy, prognosis is difficult, since diseases, like e.g. mantel cell lymphoma, can be indolent or aggressive. Here we report the characterization of NHL biopsies using epigenetic immune cell quantification. This approach is based on the identification of specifically demethylated regions in individual immune cell types. These regions are then quantified using methylation-sensitive qPCR after bisulfite conversion. This highly reproducible and objective method allows in depth immunophenotyping of the tumor microenvironment. Next to CD4+ and CD8+ T cells, B cells and NK cells more specialized immune cells like regulatory T cells (Tregs), follicular T helper cells, PD-1 expressing cells and Myeloid derived suppressor cells (MDSC) were quantitatively determined in formalin-fixed tissue samples of 251 patients with different B cell Non-Hodgkin lymphomas. As a result, characteristic immune cell distribution patterns were identified for the different lymphoma entities, including chronic lymphocytic leukemia (B-CLL) (n=41), mantle cell lymphoma (MCL) (n=32), follicular lymphoma (FL) (n=33), diffuse large B cell lymphoma (DLBCL) (n=74), marginal zone lymphoma (MZL) (n=40) and B cell acute lymphoblastic leukemia (B-ALL) (n=26). In addition, substantial heterogeneity within the entities was observed that may correlate with disease prognosis. Among others, this is particularly the case for MDSC in B-CLL patients as well as for NK cells and Tregs in MCL and PD-1+ cells in FL patients. Currently clusters within the different disease groups are analyzed with regard to the clinical outcome to investigate if disease prognosis can be predicted by epigenetic immune cell quantification. In conclusion, epigenetic immune cell quantification is a suitable method to analyze the tumor microenvironment of NHL patients with the potential to support patient’s prognosis. Citation Format: Jeannette Werner, Steffi Walter, Christoph Sachsenmaier, Janika Schulze, Deborah Phippard, Sven Olek, Barbara Seliger, Claudia Wickenhauser. Epigenetic immune cell profiling in B-non-Hodgkin lymphoma biopsies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 993.