We characterised patients with mantle cell lymphoma (MCL) with poor prognosis based on differences in immune infiltration. Different expressions of the tumour cell markers Cyclin D1 and sex-determining region Y-box transcription factor 11 (SOX11), and the immune markers cluster of differentiation 3 (CD3), CD4, CD8, CD25, forkhead box protein P3 (FoxP3), Tbox transcription factor TBX21 (T-bet), programmed cell death protein 1 (PD-1), programmed-death ligand 1 (PD-L1) and CD163 were investigated for all-cause mortality in 282 patients with MCL and time-to-progression (TTP) in 106 clinical trial patients. With increasing age, a significantly lower infiltration of CD3 + T lymphocytes was seen. T-cell infiltration was independent of cellular tumour antigen p53 (p53) expression, Ki-67, morphology and frequency of tumour cells. The all-cause mortality was higher in patients with PD-L1-expression above cut-off [hazard ratio (HR) 1Á97, 95% confidence interval (CI) 1Á18-3Á25, adjusted for sex and MCL International Prognostic Index (MIPI)] and a higher frequency of CD163 + cells (continuously, HR 1Á51, 95% CI 1Á03-2Á23, adjusting for age, sex, morphology, Ki-67 and p53). In patients treated within the Nordic Lymphoma Group MCL2/3 trials, TTP was shorter in patients with a higher frequency of FoxP3 + cells (HR 3Á22, 95% CI 1Á40-7Á43) and CD163 + cells (HR 6Á09, 95% CI 1Á84-20Á21), independent of sex and MIPI. When combined a higher frequency of CD163 + macrophages and PD-L1 + cells or high CD163 + macrophages and FoxP3 + regulatory T cells indicated worse outcome independent of established risk factors. The T-cell infiltrate was in turn independent of molecular characteristics of the malignant cells and decreased with age.

The outcome for patients with mantle cell lymphoma (MCL) has drastically improved with new treatments directed towards the tumor immune microenvironment, where macrophages play an important role. In MCL, the presence of M2 macrophages defined by CD163 expression in diagnostic biopsies has been associated with a worse prognosis. An alternative way to assess the abundance of M2 macrophages is by measuring the level of soluble CD163 in serum (sCD163). We aimed to investigate the prognostic value of sCD163 in 131 MCL patients. We found that high sCD163 at diagnosis was associated with shorter progression-free survival (PFS) and shorter overall survival (OS) (p=0.002 and p<0.001) in 81 newly diagnosed chemoimmunotherapy-treated patients. The same was seen in a cohort of 50 relapsed MCL patients mainly treated within the phase II Philemon-trial with rituximab, ibrutinib and lenalidomide (PFS p=0.016 and OS p=0.035). In newly diagnosed patients with low levels of sCD163, five-year survival was 97%. There was a moderate correlation between sCD163 and tissue CD163 (r=0.64, p=0.014). The association with a poor prognosis was independent of MIPI, Ki67, p53 status and blastoid morphology, as assessed in a multivariable Cox proportional hazards model. Here, high sCD163 was associated with both shorter PFS (HR 3.48 95% CI: 1.42-8.54) and shorter OS (HR 4.33 95% CI: 1.32-14.2), showing that high levels of the M2 macrophage marker sCD163 is an independent negative prognostic factor in MCL, both in the chemoimmunotherapy and ibrutinib/lenalidomide era. In addition, low sCD163 levels identify MCL patients with a very good prognosis.

p < 0.001), proportion of patients with ≥1 SBI (SID: 39.8%; no-SID: 9.2%; p < 0.001) and proportion of patients with ≥1 infection-associated hospitalization (SID: 27.7%; no-SID: 5.8%; p < 0.001). The most common type of infection was bacterial (SID: 63.7%; no-SID: 24.9%); in those patients who experienced an SBI, the most frequently reported infection was bacterial pneumonia.To assess overall survival, 646 and 4719 patients with and without SID, respectively, were included. Overall survival at 24 months was lower in the SID cohort (77.3%) than the no-SID cohort (87.2%). Conclusions:Patients with CLL/SLL who subsequently developed SID had a greater burden of infection than patients who did not develop SID. Increasing understanding of this burden of infection may help to

Introduction: Mantle cell lymphoma (MCL) is an incurable disease and we have previously shown that presence of CD163+ cells in the tumor microenvironment in MCL is associated with an adverse outcome. We therefore profiled CD163+ cells to better understand their impact on this tumor and identify possible targetable markers. We hypothesize that, not only the presence of CD163+ cells, a marker of M2 macrophages, in the tumor tissue, but also the spatial context of CD163+ cells might be relevant for MCL development and treatment response. Material and Methods: Sixty-nine protein targets were measured by the Nanostring GeoMx Digital Spatial Profiler. This method allowed for preserved spatial context, in tissue microarrays from a population-based cohort of de novo MCL patients while investigating different markers. A total of 235 cores from 131 different patients were sampled. Regions of interest for CD20+, CD3+ and CD163+ cells were selected, with more than 600 areas of illumination (AOI) collected. From those, 85 AOI, belonging to 61 patients, were from CD163+ cells. These were subsequently classified according to their spatial profile: CD163+ cells within the tumor area and CD163+ cells excluded from the tumor area. Differentially expressed proteins between different tissue types were also explored. Results: Among the highest expressed proteins in the CD163 AOI were CD45, HLA-DR and CD68. The higher expression of both HLA-DR and CD68 suggests that macrophages in MCL microenvironment may display mixed phenotypes between pro- and anti-inflammatory stages, the called M1 and M2 polarization types. Interestingly, p53 and Ki67 were highly correlated among the CD163 AOI collected, which might suggest higher aggressiveness of CD163+ cells. We explored the differently expressed proteins between CD163 AOI sampled located within the tumor and excluded from the tumor/tumor barrier. We identified significant differences in the expressed proteins between the two groups, such as p53, VISTA, ARG1, LAG3 and HLA-DR. p53 was higher in the CD163 AOI within the tumor area, whereas VISTA was highest expressed in CD163 AOI excluded from the tumor cells/tumor barrier. Among the 85 CD163+ AOIs, 47 were sampled from lymph node biopsies, 14 from bone marrow, 10 from tonsil samples, four from the gastrointestinal tract, six from other tissue types and four from unknown origin. Principal component analysis and k-means clustering showed that most of bone marrow and gastrointestinal tract biopsies clustered apart from the remaining samples, with a few differentially expressed proteins, such as NF1 and CD66b. Conclusions: Our study demonstrates that spatial localization within the MCL tumor affects the expression of CD163+ macrophages, adding to the premise that macrophages in tumor are not easily characterized by the concept of M1 and M2 types. Our results shed light on targetable features of the MCL tumor microenvironment. Citation Format: Joana Matos Rodrigues, Lavanya Lokhande, Anna Gerdtsson, Anna Nikkarinen, Peter Hollander, Anna Porwit, Ingrid Glimelius, Mats Jerkeman, Sara Ek. Spatially resolved multiplexed analysisreveals how macrophages adapt to the mantle cell lymphoma microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2026.