T-cell receptor γδ T-cell leukemia with the morphology of T-cell prolymphocytic leukemia and a postthymic immunophenotype

T-cell prolymphocytic leukemia (T-PLL) is a postthymic T-cell neoplasm with a characteristic morphology and heterogeneous immunophenotype. Most cases of T-PLL express membrane T-cell receptors (TCRs) of the alphabeta phenotype. We experienced a 30-year-old man suffering from TCRgammadelta T-cell leukemia with morphology compatible to T-PLL with a postthymic phenotype. He was admitted with skin eruption and pancytopenia. Peripheral blood and bone marrow were occupied with medium-sized lymphocytes, which had moderately condensed chromatin with a single nucleolus and sparse, nongranular basophilic cytoplasm. The immunophenotype was CD1a-, CD2-, CD3+, CD4-, CD5+, CD7+, CD8-, and terminal deoxynucleotidyl transferase negative. Hepatosplenomegaly was absent. He was diagnosed as having T-PLL and was treated with combination chemotherapy. Six months later the leukemic cell became chemoresistant. Although the patient showed transient improvement in response to pentostatin, he died 13 months after the diagnosis. To our knowledge, this is the first case of T-PLL with a TCRgammadelta phenotype.     

Hepatosplenic γδ T-cell lymphoma

AIM: To investigate the clinicopathologic characteristics, immunophenotype and TCR gene rearrangements of hepatosplenic T-cell lymphoma in eight Chinese patients. METHODS: Eight Chinese patients with hepatosplenic γδ T-cell lymphomas were studied. Hematoxylin-eosin-stained slides and clinical histories were reviewed. We also carried out immunohistochemical staining for CD3, CD4, CD8, CD20, CD43, CD56, CD79a, UCHL-1, and TCR γδ. Rearrangements of TCR gamma and delta chain genes were also studied. RESULTS: The spleens were enlarged and the cut surfaces were homogeneous and red-purple in color without identifiable gross lesions or enlarged hilar lymph nodes. Histologically, Iymphoma cells infiltrated the cords of Billroth and often packed the sinuses. Liver biopsy showed Iymphoma cell infiltrations in the sinusoids, and three cases showed involvements of the portal tracts. Immunohistochemically Iymphoma cells were positive for CD3, CD43, and CD56 in all cases. Four of eight cases were positive for CD8, and all cases were negative for CD4 (6/6). Monoclonal rearrangements of TCR γ gene were demonstrated by PCR analysis in five out of the eight cases. TCR δ gene rearrangements were detected in six out of the eight cases, which demonstrated single bands on PAGE gel, and the amplification products in two cases were confirmed by sequencing. CONCLUSION: The clinicopathology of hepatosplenic γδ T-cell lymphoma in Chinese patients is similar to what was previously reported except that the splenomegaly is not so massive, and CD8 is positive.     

Hepatosplenic γδ T-cell lymphoma

AIM: To investigate the clinicopathologic characteristics, immunophenotype and TCR gene rearrangements of hepatosplenic T-cell lymphoma in eight Chinese patients. METHODS: Eight Chinese patients with hepatosplenic 76 T-cell lymphomas were studied. Hematoxylin-eosin-stained slides and clinical histories were reviewed. We also carried out immunohistochemical staining for CD3, CD4, CD8, CD20, CD43, CD56, CD79a, UCHL-1, and TCR γδ. Rearrangements of TCR gamma and delta chain genes were also studied. RESULTS: The spleens were enlarged and the cut surfaces were homogeneous and red-purple in color without identifiable gross lesions or enlarged hilar lymph nodes. Histologically, lymphoma cells infiltrated the cords of Billroth and often packed the sinuses. Liver biopsy showed lymphoma cell infiltrations in the sinusoids, and three cases showed involvements of the portal tracts. Immunohistochemically lymphoma cells were positive for CD3, CD43, and CD56 in all cases. Four of eight cases were positive for CD8, and all cases were negative for CD4 (6/6). Monoclonal rearrangements of TCR y gene were demonstrated by PCR analysis in five out of the eight cases. TCR δ gene rearrangements were detected in six out of the eight cases, which demonstrated single bands on PAGE gel, and the amplification products in two cases were confirmed by sequencing. CONCLUSION: The clinicopathology of hepatosplenic γδ T-cell lymphoma in Chinese patients is similar to what was previously reported except that the splenomegaly is not so massive, and CD8 is positive.     

Can one target T-cell ALL?

Progress in our understanding of the central genes, pathways, and mechanisms in the pathobiology of T-cell acute lymphoblastic leukemia (T-ALL) has identified key drivers of the disease, opening new opportunities for therapy. Drugs targeting highly prevalent genetic alterations in NOTCH1 and CDKN2A are being explored, and multiple other targets with readily available therapeutic agents, and immunotherapies are being investigated. The molecular basis of T-ALL is reviewed here and potential targets and therapeutic targets discussed.     

Angioimmunoblastic T-cell lymphoma: a relatively common type of T-cell lymphoma in Sjögren's syndrome

An increased risk of developing lymphoma has been indicated in Sj?gren's syndrome (SS), and the lymphomas in SS are usually B-cell type in origin. Interestingly, despite the rather low frequency of T-cell lymphoma in SS, angioimmunoblastic T-cell lymphoma (AILD) constitute the majority of T-cell lymphomas associated with SS. To the best of our knowledge, including our case, at least 11 out of 23 (48%) cases of T-cell lymphoma reported in association with SS, were AILD. The fact that the development of B-cell lymphoma in SS is much more frequent than that of T-cell lymphoma, might be explained by differences in the situation between B and T cells, although the exact mechanism still remains uncertain.     

Antibody therapy for Adult T-cell leukemia–lymphoma

Adult T-cell leukemia–lymphoma (ATL) has a very poor prognosis. Since there currently are limited treatment options for ATL patients, several novel agents are being developed and tested clinically. Antibody therapy against ATL was initially started with interleukin-2 receptor α-subunit, CD25, as a target molecule in the late 1980s, and is currently ongoing. CC chemokine receptor 4 (CCR4) was postulated as a novel molecular target in ATL antibody therapy, and humanized anti-CCR4 mAb (KW-0761), whose Fc region was defucosylated to enhance antibody-dependent cellular cytotoxicity, was developed. A phase I study of KW-0761 in relapsed ATL and peripheral T-cell lymphoma was started in 2006, and a subsequent phase II study was completed in 2010. KW-0761 showed a clinically meaningful antitumor activity in patients with relapsed ATL, with an acceptable toxicity profile. The prognosis of ATL patients should be improved in the near future with clinical applications of novel treatment strategies, including those involving KW-0761 and other promising antibody therapies targeting CD25 or CD30.     

Blastic NK-cell lymphoma/leukemia with T-cell receptor γ rearrangement

A 79-year-old Japanese man was admitted to our hospital with dyspnea in June 1999. Physical examination revealed general exanthema, hepatosplenomegaly, and lymphadenopathy. Increased numbers of abnormal cells were observed in peripheral blood; these cells were of lymphoblastic morphology with high nuclear/cytoplasm ratios and few azurophilic granules. Immunophenotypic analysis revealed positivity for CD2, CD4, CD56, and HLA-DR, and negativity for CD3, CD13, CD16, CD33, CD34, and T cell receptor (TCR). On genotypic analysis, TCRgamma chain was rearranged, but neither the TCRbeta chain nor TCRdelta chain. Despite an initial good response to chemotherapy the disease relapsed in the early stage, and the patient died 6 months after diagnosis.     

TGF-β regulates T-cell neurokinin-1 receptor internalization and function

Substance P (SP) is a proinflammatory mediator implicated in inflammatory bowel disease (IBD) and other inflammatory states. SP acts by stimulating the neurokinin-1 receptor (NK-1R) on T lymphocytes and other cell types, and regulates these cells in a complex interplay with multiple cytokines. The mechanisms of interaction among these inflammatory mediators are not yet fully understood. Here, we demonstrate that function of the NK-1R, a member of the G protein-coupled receptor (GPCR) superfamily, is modulated by TGF-β. The latter acts not on a GPCR but via serine-threonine kinase-class receptors. By flow confocal image analysis, we demonstrate that TGF-β delays SP-induced NK-1R internalization on mucosal T cells isolated from a mouse model of IBD and on granuloma T cells in murine schistosomiasis. Furthermore, luciferase reporter-gene assays revealed that NK-1R stimulation activates the nuclear factor of activated T cell- and activator protein-1-dependent signaling pathways, which are known triggers of effector T-cell cytokine production. TGF-β markedly increases SP-induced activation of these signaling cascades, suggesting that delayed NK-1R internalization results in enhanced signaling. Providing a link to amplified immune function, SP and TGF-β, when applied in combination, trigger a strong release of the proinflammatory cytokines IFN-γ and IL17 from intestinal inflammatory T cells, whereas either agonist alone shows no effect. These observations establish precedent that members of two distinct receptor superfamilies can interact via a previously unrecognized mechanism, and reveal a paradigm of GPCR transregulation that is relevant to IBD and possibly other disease processes.     

Adult T-cell lymphoma mimicking Henoch–Schönlein purpura

We report a male patient with adult T-cell lymphoma, who was initially diagnosed clinically as having Henoch–Schönlein purpura (HSP) with abdominal pain and specific purpura. Adult T-cell lymphoma-like cells were minimal and abdominal lymph nodes were transiently swollen, and the symptoms were improved by supportive management. Although the clinical course was compatible with HSP, the histological examination revealed infiltration of lymphocytes rather than neutrophils. Later he developed lymphoma and was treated with chemotherapy. This rare case suggests the importance of skin biopsies to seek the underlying pathology in adult HSP.