Diffuse large B cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma (NHL), accounting for about 40% of all cases NHL. Analysis of the tumour microenvironment is an important aspect of the assessment of the progression of DLBCL. In this review article, we have analyzed the role of different cellular components of the tumour microenvironment, including mast cells, macrophages, lymphocytes, in tumour progression of DLBCL. We examined several approaches to confront the available pieces of evidence; three key points emerged. DLBCL is a disease of malignant B-cells spreading and accumulating both at nodal and in extranodal sites. Both in patients with nodal and extranodal lesions, the subsequent induction of a cancer-friendly environment appears pivotal. DLBCL cell interaction with mature stromal cells and vessels confers tumour protection and inhibition of immune response while delivering nutrients and oxygen supply. Single cells may also reside and survive in protected niches in the nodal and extranodal sites as a source for residual disease and relapse. This review aims to molecularly and functionally recapitulate the DLBCL-milieu crosstalk, to relate niche and pathological angiogenic constitution and interaction factors to DLBCL progression.

In tumour cells of more than 20 different cancer types, the CXCR4-CXCL12-axis is involved in multiple key processes including proliferation, survival, migration, invasion, and metastasis. Since data on this axis in diffuse large B cell lymphoma (DLBCL) are inconsistent and limited, we comprehensively studied the CXCR4-CXCL12-axis in our DLBCL cohort as well as the effects of CXCR4 antagonists on lymphoma cell lines in vitro. In DLBCL, we observed a 140-fold higher CXCR4 expression compared to non-neoplastic controls. Interestingly, high expression of CXCR4 was associated with poor clinical outcome. Furthermore, in corresponding bone marrow biopsies, we observed a correlation of CXCL12 expression and lymphoma infiltration rate as well as a reduction of CXCR4 expression in remission of bone marrow involvement after treatment. Furthermore, the niacin derivate of the CXCR4 antagonist AMD070, which was synthesized by us, demonstrated stronger pro-apoptotic effects than AMD070 in vitro and induced expression of certain pro-apoptotic genes in CXCR4 positive lymphoma cell lines. Finally, WK1 treatment resulted in reduced expression of JNK-, ERK1/2- and NFκB/BCR-target genes. These data indicate that the CXCR4-CXCL12-axis impacts the pathogenesis of DLBCL and represents a potential therapeutic target in aggressive lymphomas.

Severe combined immunodeficiency disorders (SCID) are a genetically heterogeneous group of inherited defects characterized by severe abnormalities of immune system development and function that lead to a wide spectrum in clinical manifestations. A subgroup of patients presents a disabling and life-threatening clinical course. In these cases, allogeneic hematopoietic stem cell transplant provides a curative approach. The occurrence of SCID-associated lymphoproliferative disorders is rare and occur mostly in adenosine deaminase-deficient severe combined immunodeficiency disorders, after allogeneic hematopoietic stem cell transplant. Epstein Barr virus infection is present in the majority of individuals with primary immunodeficiency developing lymphoma, revealing compromised anti-tumour surveillance of virally transformed cells. Herein, we report a rare case of diffuse large B cell lymphoma occurring in an Epstein Barr virus negative, non-transplanted X-linked severe combined immunodeficiency 4-months-old infant, successfully treated with immunotherapy and allogeneic stem cell transplantation. This case suggests that Epstein Barr virus -independent mechanism of neoplastic transformation must take action in severe combined immunodeficiency associated lymphoma and unveils the curative potential of donor T cells after allogeneic transplantation.

Soluble CD163 (sCD163) functions as a scavenger receptor for haptoglobin-hemoglobin complexes, and is mostly expressed by monocytes and macrophages. The level of soluble CD163 has been used to determine macrophage activation. Our goal was to determine whether the loading of M2 CD163 positive tumor-associated macrophages (TAMs) through the secretion of sCD163 affects overall survival in patients with DLBCL and eventually discriminates subgroups of patients with different prognosis. sCD163 levels were measured in 40 frozen serum samples from patients diagnosed with DLBCL and 30 healthy individuals (HI) using an enzyme-linked immunosorbent assay (ELISA). Statistical analyses were performed using SPSS version 28. The results showed that patients who achieved complete response after standard-of-care immuno-chemotherapy and were alive and disease-free after 12 months of follow-up, but had elevated sCD163 levels (above median) at diagnosis, presented a significantly worse overall survival compared to those with initial serum sCD163 levels below median (p=0.03). Consequently, serum sCD163 level in DLBCL patients may constitute a marker of long-term response to chemo-immunotherapy.