Expression of TIA1 and PAX5 in Classical Hodgkin Lymphoma at Initial Diagnosis May Predict Clinical Outcome

The Prognostic Value of Eight Immunohistochemical Markers Expressed in the Tumor Microenvironment and on Hodgkin Reed-Sternberg Cells in Pediatric Patients With Classical Hodgkin Lymphoma

Immunohistochemical markers are associated with treatment outcome in adults with classical Hodgkin Lymphoma (cHL). Studies in children are scarce and inconsistent. We investigated in 67 children with cHL, whether the expression of CD15, CD30, PAX5, PD-1, PD-L1, CD68, CD163 and TARC at diagnosis is associated with disease free survival (DFS) and with interim remission status. Low CD15 and low TARC expression were associated with relapsed disease. Low expression of PD-L1 was associated with complete remission at interim PET-scan. Our data suggest a difference between pediatric and adult cHL. This underlines the importance of future research into specific prognostic factors in pediatric cHL, indispensable for improvement of treatment in this population.

The Multifunctional Faces of T-Cell Intracellular Antigen 1 in Health and Disease

T-cell intracellular antigen 1 (TIA1) is an RNA-binding protein that is expressed in many tissues and in the vast majority of species, although it was first discovered as a component of human cytotoxic T lymphocytes. TIA1 has a dual localization in the nucleus and cytoplasm, where it plays an important role as a regulator of gene-expression flux. As a multifunctional master modulator, TIA1 controls biological processes relevant to the physiological functioning of the organism and the development and/or progression of several human pathologies. This review summarizes our current knowledge of the molecular aspects and cellular processes involving TIA1, with relevance for human pathophysiology.

Immunosuppressive Microenvironment and Efficacy of PD-1 Inhibitors in Relapsed/Refractory Classic Hodgkin Lymphoma: Checkpoint Molecules Landscape and Macrophage Populations

Simple Summary

Classic Hodgkin lymphoma contains rare malignant Hodgkin/Reed–Sternberg cells and abundant reactive populations in the tumor microenvironment. Many aspects of the interaction between tumor cells and immune cells remain unclear. Nevertheless, the microenvironment is believed to play a crucial role in tumor resistance and progression. Current knowledge about the role and dynamics of the tumor microenvironment in Hodgkin lymphoma during anti-PD-1 treatment is limited. The aim of this study was to identify possible predictive and prognostic morphological markers in the treatment of patients with relapsed or refractory classic Hodgkin lymphoma treated with nivolumab and to assess the variability of reactive cell populations after nivolumab therapy. The study was aimed to optimize therapeutic strategy in patients with relapsed or refractory classic Hodgkin lymphoma.

Abstract

To date, the impact of the tumor microenvironment on the prognosis of patients with classic Hodgkin lymphoma (cHL) during anti-PD-1 therapy has been studied insufficiently. This retrospective study included 61 primary samples of lymph nodes from patients who had relapsed/refractory (r/r) cHL and were treated with nivolumab. Repeated samples were obtained in 15 patients at relapse or disease progression after immunotherapy. Median follow-up was 55 (13–63) months. The best overall response rate and progression-free survival (PFS) were analyzed depending on the expression of CD68, CD163, PD-1, LAG-3, TIM-3, CTLA-4, TIGIT, CD163/c-maf in the tumor microenvironment in primary and sequential biopsies. The combination of CD163/c-maf antibodies was used for the identification of M2 macrophages (M2). A low number of macrophages in primary samples was associated with inferior PFS during nivolumab treatment (for CD163-positive cells p = 0.0086; for CD68-positive cells p = 0.037), while a low number of M2 with higher PFS (p = 0.014). Complete response was associated with a lower level of M2 (p = 0.011). In sequential samples (before and after nivolumab therapy) an increase in PD-1 (p = 0.011) and LAG-3 (p = 0.0045) and a depletion of CD68 (p = 0.057) and CD163 (p = 0.0049)-positive cells were observed. The study expands understanding of the cHL microenvironment structure and dynamics during nivolumab therapy in patients with r/r cHL.

The Triple Positivity for EBV, PD-1, and PD-L1 Identifies a Very High Risk Classical Hodgkin Lymphoma

BACKGROUND

The programmed death receptor (PD-1) and ligand (PD-L1) pathway act by suppressing the antitumor response in chronic Hodgkin lymphoma (cHL). In this study, we aimed to investigate the effect of PD-1, PD-L1, and Epstein-Barr virus (EBV) positivity on prognosis at the initial diagnosis of cHL.

MATERIAL AND METHODS

Thirty-six patients with cHL were retrospectively analyzed. PD-L1 staining was performed for RS cells and tumor microenvironment in the biopsy materials of cases. The presence of EBV was investigated by EBER (EBV-encoded RNA) method in tumor cell. P < .05 was accepted as significant.

RESULTS

The presence of advanced-stage disease, B symptoms, intermediate or high-risk international prognostic index (IPS), and extranodal involvement were found to be related to both PD-L1 positivity and EBV positivity in RS cells. PD-L1 positivity in RS cells was also associated with EBV positivity. There were 6 (16.7%) triple-positive (EBV⁺, RS-PD-L1⁺, mic-PD-1⁺) patients. All of these patients had advanced-stage disease, B symptoms at the time of diagnosis, and intermediate-high IPS score, and 4 of 6 patients had extranodal involvement. This group also had significantly shortened overall survival compared with others (38.4 months vs. 67.9 months P = .024).

CONCLUSION

Our data suggest that there is correlation between PD-L1 positivity and EBV positivity in tumor RS cells that are also associated with extranodal involvement, intermediate and high IPS score, presence of B symptoms, and advanced-stage disease. In addition, we identified a group of triple-positive (EBV⁺, RS-PD-L1⁺, mic-PD-1⁺) cHL patients who have a very high-risk disease.

Expression of the immune checkpoint receptor TIGIT in Hodgkin's lymphoma

Hodgkin's lymphoma (HL) is characterized by a high background of inflammatory cells which play an important role for the pathogenesis of the disease. T cell immunoreceptor with Ig and ITIM domains (TIGIT) is an inhibitory immune checkpoint receptor and a putative target for novel immunotherapies. To study patterns of TIGIT expression in the T cell background surrounding malignant cells including Hodgkin cells, Reed-Sternberg cells and histiocytic cells, a microenvironment (ME) tissue microarray (TMA) was constructed from tissue punches measuring 2 mm in diameter obtained from formalin-fixed tissue samples of Hodgkin's lymphoma lymph nodes (n = 40) and normal human tonsil (n = 2). The ME-TMA was stained by brightfield and fluorescence multiplex immunohistochemistry (IHC) to evaluate expression levels of TIGIT and PD-1 as well as standard lymphocyte markers (CD3, CD8, CD4, FOXP3) in the lymphocytic background. All analyzed cases of HL contained 9-99% (median: 86%) of TIGIT+ lymphoid cells. In general, TIGIT localized to the same cells as PD-1. Strikingly, expression levels of TIGIT and PD-1 were highly variable among the analyzed samples. Highest levels of TIGIT and PD-1 were found in one sample of nodular lymphocytic-predominant HL (NLPHL). In conclusion, TIGIT expression is highly variable between patients with Hodgkin's lymphoma. Our results encourage further studies evaluating the role of TIGIT as a target for immunotherapies in Hodgkin's lymphoma.

Flow cytometry for assessment of the tumor microenvironment in pediatric Hodgkin lymphoma

BACKGROUND

The role of flow cytometry in diagnosis and management of Hodgkin lymphoma (HL) remains limited. As knowledge emerges of the tumor microenvironment in this disease, various methods are being evaluated in its study. This study examines the microenvironment using flow cytometry to assess differences between subtypes and clinicopathologic correlates.

PROCEDURE

A retrospective cross-sectional study was performed analyzing the tumor immunophenotype, by flow cytometry, for 31 children with classical HL. Correlation was made with patient information, including outcome.

RESULTS

The makeup of the tumor microenvironment varies across subtype of HL, with T cells predominating in nodular sclerosis (NS), and similar proportions of B and T cells in mixed cellularity (MC). CD4 cells predominate in NS, whereas CD8 more so in MC subtype. The rate of continuous complete remission is significantly higher in the MC subgroup. Last, the proportion of HLA-DR/CD38 copositive lymphocytes was an independent prognostic factor for relapse/refractoriness.

CONCLUSIONS

This study indicates that flow cytometry can be used to examine the tumor microenvironment in HL and that percentage of HLA-DR/CD38 copositive lymphocytes may be a biomarker for relapse and refractoriness in pediatric HL.

PAX5-Negative Classical Hodgkin Lymphoma: A Case Report of a Rare Entity and Review of the Literature

Classical Hodgkin lymphoma (CHL) is recognized as a B-cell neoplasm arising from germinal center or postgerminal center B-cells. The hallmark of CHL is the presence of CD30 (+) Hodgkin and Reed-Sternberg (HRS) cells with dim expression of PAX5. Nearly all of the HRS cells are positive for PAX5. However, a small minority of HRS cells may lack PAX5 expression, which can cause a diagnostic dilemma. Herein we describe two cases of PAX5-negative CHL and review of the English literature on this very rare entity. It is crucial to be aware of this phenomenon, which in some cases may lead to misdiagnosis and may ultimately adversely affect patient's management.

High proportions of PD-1+ and PD-L1+ leukocytes in classical Hodgkin lymphoma microenvironment are associated with inferior outcome

Immune checkpoint inhibition targeting the programmed death receptor (PD)-1 pathway is a novel treatment approach in relapsed and refractory classical Hodgkin lymphoma (cHL). Identifying patients with a high risk of treatment failure could support the use of PD-1 inhibitors as front-line treatment. Our aim was to investigate the prognostic impact of PD-1, programmed death-ligand 1 (PD-L1), and PD-L2 in the tumor microenvironment in diagnostic biopsies of patients with cHL. Patients from Denmark and Sweden, diagnosed between 1990 and 2007 and ages 15 to 86 years, were included. Tissue microarray samples were available from 387 patients. Immunohistochemistry was used to detect PD-1, PD-L1, and PD-L2, and the proportions of positive cells were calculated. Event-free survival (EFS; time to treatment failure) and overall survival (OS) were analyzed using Cox proportional hazards regression. High proportions of both PD-1⁺ (hazard ratio [HR], 1.77; 95% confidence interval [CI], 1.10-2.86) and PD-L1⁺ (HR = 1.89; 95% CI, 1.08-3.30) leukocytes in the microenvironment were associated with inferior EFS in a multivariate analysis (adjusted for white blood cell count >15 × 10⁹/L, hemoglobin <105 g/L, albumin <40 g/L, B symptoms, extranodal involvement, stage, bulky tumor, nodular sclerosis subtype, Epstein-Barr virus status, lymphocyte count <0.6 × 10⁹/L, sex, and country). A high proportion of PD-L1⁺ leukocytes was also associated with inferior OS in a multivariate analysis (HR, 3.46; 95% CI, 1.15-10.37). This is the first study to show a correlation after multivariate analysis between inferior outcome in cHL and a high proportion of both PD-1⁺ and PD-L1⁺ leukocytes in the tumor microenvironment.