Here, we have demonstrated that TET2 loss and RhoAG17V expression in mature murine T cells cooperatively cause abnormal CD4+ T cell proliferation and differentiation by perturbing FoxO1 gene expression, phosphorylation, and subcellular localization, an abnormality that is also detected in human primary AITL tumor samples.
Among PTCL-NOS, a heterogeneous group of lymphoma-comprising cases likely to derive from Th follicular (T(FH)) cells similarly to AITL, TET2 mutations were more frequent when PTCL-NOS expressed T(FH) markers and/or had features reminiscent of AITL (58% vs 24%, P = .01).
Moreover, significantly higher Ang1 and Tie2 expression was detected in AILT cases with CD10-positive neoplastic T-cells by comparison with unspecified peripheral T-cell lymphoma (14 cases).
Angioimmunoblastic T-cell lymphoma (AITL) has increased neoplastic follicular-helper T cells (FHT), which often express CD10; but nonneoplastic, CD10-positive T cells may be associated with reactive lymphadenopathy and with B-cell lymphomas.
Among PTCL-NOS, a heterogeneous group of lymphoma-comprising cases likely to derive from Th follicular (T(FH)) cells similarly to AITL, TET2 mutations were more frequent when PTCL-NOS expressed T(FH) markers and/or had features reminiscent of AITL (58% vs 24%, P = .01).
Our data show that aberrant CD10 expression is a useful phenotypic marker for diagnosis of AITL in most involved extranodal sites, except bone marrow, and suggest a possible role of FDC in the pathogenesis of AITL.
Angiogenic mediators angiopoietin (Ang) 1 (ANGPT1), Ang2 (ANGPT2) and their receptor, Tie2 (TEK), vascular endothelial growth factor (VEGF; VEGFA) and its receptor, VEGFR2 (KDR), and hepatocyte growth factor (HGF) and its receptor, c-Met (MET) were all more highly expressed in AILT lymph nodes (16 cases) than in B-cell lymphomas (24 cases).
Notably, we found that the vascular endothelial growth factor (VEGF) was expressed not only by reactive cells, but also by neoplastic cells, and that nuclear factor-kappaB (NF-kappaB) activation is uncommon in AILT, as suggested by frequent exclusively cytoplasmic c-REL localization.
Antibodies specific to phosphorylated ZAP70, ITK and PLCγ1 were used to identify the activation status of intracellular proteins involved in TCR signaling in AITL patients.
This prompted us to study CD30 immunohistochemical (IHC) expression and mRNA levels by reverse transcription polymerase chain reaction (RT-PCR) in a different series of 51 cases (43 AITLs and 8 PTCL-NOSs) in routine samples.
Furthermore, 58.1% of patients with PTCL-NOS, 57.1% of patients with NK/TCL, 53.3% of patients with ALCL and 60% of patients with AITL highly expressed HDAC2.
Angiogenic mediators angiopoietin (Ang) 1 (ANGPT1), Ang2 (ANGPT2) and their receptor, Tie2 (TEK), vascular endothelial growth factor (VEGF; VEGFA) and its receptor, VEGFR2 (KDR), and hepatocyte growth factor (HGF) and its receptor, c-Met (MET) were all more highly expressed in AILT lymph nodes (16 cases) than in B-cell lymphomas (24 cases).
We performed genome-wide microRNA (miRNA) profiling on 33 ALK-positive (ALK[+]) ALCLs, 25 ALK-negative (ALK[-]) ALCLs, 9 angioimmunoblastic T-cell lymphomas, 11 peripheral T-cell lymphomas not otherwise specified (PTCLNOS), and normal T cells, and demonstrated that ALCLs express many of the miRNAs that are highly expressed in normal T cells with the prominent exception of miR-146a.
Results revealed that 55.8% of patients with PTCL-NOS, 57.1% of patients with NK/TCL, 86.7% of patients ALCL and 50% of patients with AITL highly expressed HDAC1.
We measured serum levels of IL-5, IL-10, IL-12, and interferon-gamma (IFN-γ) at diagnosis in AITL and other common subtypes of nodal T-cell lymphoma including peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), ALK-negative anaplastic large cell lymphoma (ALCL) or ALK-positive ALCL between September 2008 and December 2014.