In vitro and in vivo effects of 2'-deoxycoformycin (Pentostatin) on tumour cells from human gammadelta+ T-cell malignancies

The Diverse Roles of γδ T Cells in Cancer: From Rapid Immunity to Aggressive Lymphoma

γδ T cells are unique players in shaping immune responses, lying at the intersection between innate and adaptive immunity. Unlike conventional αβ T cells, γδ T cells largely populate non-lymphoid peripheral tissues, demonstrating tissue specificity, and they respond to ligands in an MHC-independent manner. γδ T cells display rapid activation and effector functions, with a capacity for cytotoxic anti-tumour responses and production of inflammatory cytokines such as IFN-γ or IL-17. Their rapid cytotoxic nature makes them attractive cells for use in anti-cancer immunotherapies. However, upon transformation, γδ T cells can give rise to highly aggressive lymphomas. These rare malignancies often display poor patient survival, and no curative therapies exist. In this review, we discuss the diverse roles of γδ T cells in immune surveillance and response, with a particular focus on cancer immunity. We summarise the intriguing dichotomy between pro- and anti-tumour functions of γδ T cells in solid and haematological cancers, highlighting the key subsets involved. Finally, we discuss potential drivers of γδ T-cell transformation, summarising the main γδ T-cell lymphoma/leukaemia entities, their clinical features, recent advances in mapping their molecular and genomic landscapes, current treatment strategies and potential future targeting options.

Use of PEG-asparaginase in a case of Hepatosplenic γδ T-cell lymphoma with long-term remission after stem cell transplantation

Hepatosplenic γδ T-cell lymphoma (HSTCL) is a rare aggressive peripheral T-cell lymphoma. Prognosis is usually poor with a median survival between 8 and 16 months after traditional chemotherapy. Stem cell transplantation (SCT) is promising and with a more intense induction regimen, has yielded positive results. We report the use of pegylated-asparaginase (PEG-asparaginase) along with a conventional anthracycline-containing regimen in a 51-year-old male who was diagnosed with HSTCL, achieved a complete remission, and subsequently underwent peripheral blood SCT and remained in remission at the time of this case report.

Gamma-delta t-cell lymphomas

Gamma-delta T-cell lymphomas are aggressive and rare diseases originating from gamma-delta lymphocytes. These cells, which naturally play a role in the innate, non-specific immune response, develop from thymic precursor in the bone marrow, lack the major histocompatibility complex restrictions and can be divided into two subpopulations: Vdelta1, mostly represented in the intestine, and Vdelta2, prevalently located in the skin, tonsils and lymph nodes. Chronic immunosuppression such as in solid organ transplanted subjects and prolonged antigenic exposure are probably the strongest risk factors for the triggering of lymphomagenesis. Two entities are recognised by the 2008 WHO Classification: hepatosplenic gamma-delta T-cell lymphoma (HSGDTL) and primary cutaneous gamma-delta T-cell lymphoma (PCGDTL). The former is more common among young males, presenting with B symptoms, splenomegaly and thrombocytopenia, usually with the absence of nodal involvement. Natural behaviour of HSGDTL is characterised by low response rates, poor treatment tolerability, common early progression of disease and disappointing survival figures. PCGDTL accounts for <1% of all primary cutaneous lymphomas, occurring in adults with relevant comorbidities. Cutaneous lesions may vary, but its clinical behaviour is usually aggressive and long-term survival is anecdotal. Available literature on gamma-delta T-cell lymphomas is fractioned, mostly consisting of case reports or small cumulative series. Therefore, clinical suspicion and diagnosis are usually delayed, and therapeutic management remains to be established. This review critically analyses available evidence on diagnosis, staging and behaviour of gamma-delta T-cell lymphomas, provides recommendations for therapeutic management in routine practice and discusses relevant unmet clinical needs for future studies.

Hepatosplenic γδ T-cell lymphoma: an overview

Peripheral T-cell lymphomas are a heterogeneous group of lymphoid malignancies. Among these, hepatosplenic γδ T-cell lymphoma (HTCL) represents an aggressive and treatment-resistant subgroup for which new avenues of treatment are critically needed. HTCL is characterized by primary extranodal distribution of the malignant cells with typical intrasinusoidal infiltration of the liver, spleen, and bone marrow, which results in hepatosplenomegaly and peripheral blood cytopenias. Another characteristic feature is the expression of γδ T-cell receptors. HTCL exhibits a rapid progressive course and an extremely poor response to currently known therapeutic strategies, with a 5-year overall survival rate of only 7%. In this review, we discuss the clinical, pathologic, and molecular characteristics of this disease, along with the challenges that are associated with its diagnosis and treatment.

Hepatosplenic alpha/beta T-cell lymphoma masquerading as cirrhosis

A 59-year-old man with diabetes mellitus, prior hepatitis B infection and recently diagnosed cirrhosis with prior Babesiosis presented to our institution from an outside hospital with six months of worsening abdominal pain, myalgias and fevers. On admission, physical examination revealed jaundice, hepatosplenomegaly and diffuse lymphadenopathy. Laboratory investigations demonstrated mild anemia, thrombocytopenia, hyperbilirubinemia and elevated lactate dehydrogenase. Tests for human immunodeficiency virus, and active Babesia microti infection were negative, however Epstein-Barr virus DNA by quantitative PCR was markedly elevated. CT scan revealed features suggestive of a cirrhotic liver without focal mass lesions as well as massive splenomegaly with axillary, retroperitoneal and inguinal lymphadenopathy. Bone marrow and lymph node biopsies were obtained which ultimately revealed hepatosplenic T-cell lymphoma. The patient's initial liver biopsy from five months prior to presentation was re-evaluated by our institution's pathologists. Histologic analysis showed hepatic sinusoidal and portal infiltration of atypical lymphocytes morphologically identical to those present on the more recently excised lymph node tissue. The hepatic sinusoidal lymphoid cells were strongly positive for CD2, CD3 and CD5 whereas CD4, CD8 stained only minor subsets of the T cells. Subsequent flow cytometric immunophenotypying of peripheral blood identified T-cell receptor alpha/beta positive cells that lacked CD4 and CD8 (double negative alpha/beta T cells). Given the established bone marrow involvement, he was diagnosed with stage IV disease and treated with chemotherapy. His clinical course involved multiple hospitalizations complicated by hyponatremia, neutropenic fevers and pulmonary emboli. Following his fourth cycle of chemotherapy, he developed worsening liver failure and expired approximately three months after initial diagnosis of lymphoma. Hepatosplenic lymphoma of alpha/beta T cells is a rare malignancy with largely unclear risk factors and varied clinical presentations. Notably, diffuse infiltration of liver parenchyma is a prominent feature and the disease can mimic cirrhosis clinically as well as radiographically. Early recognition of this aggressive lymphoma is important and should be considered in the evaluation of patients in whom the etiology of cirrhosis remains in question.

Hepatosplenic gamma-delta T-cell lymphoma

Hepatosplenic T-cell lymphoma (HSTL) is a rare and aggressive extranodal lymphoma derived mostly from cytotoxic γδ T-cells. The peak incidence is in adolescents and young adults, and is more common in males. Up to 20% of HSTL arise in the setting of chronic immune suppression, most commonly solid organ transplantation or prolonged antigenic stimulation. Patients present with systemic symptoms (fever), abdominal pain, weakness, and marked hepatosplenomegaly in the absence of lymphadenopathy. Patients usually manifest marked thrombocytopenia, often with anaemia and leucopenia, a leukemic phase, and bone marrow involvement in 80% of cases. Lactate dehydrogenase levels are usually markedly elevated. HSTL exhibits a marked chemoresistance to currently used regimens, a rapidly progressive behavior, and dismal prognosis. Patients with post-transplant HSTL exhibit an especially poor outcome. Standard treatment has yet to be established. Anthracycline-based chemotherapy is associated with a satisfactory response in two thirds of patients, but poor long-term results. Complete remission is extremely uncommon, and most patients die from lymphoma within two years of diagnosis. A prognostic correlation between outcome and degree of thrombocytopenia has been reported. Relapsing disease is usually chemorefractory and fast growing, and patients' performance status and clinical conditions are poor. These aspects, as well as the lack of drugs with proven activity against HSTL, render salvage treatment almost impossible. A few cases of HSTL successfully treated with autologous or allogeneic stem-cell transplantation have been reported. The use of 2'-deoxycoformycin and other targeted therapies, such as alemtuzumab, anti-γδ TCR monoclonal antibodies, and anti-CD44 therapy, have shown promising results in anecdotal reports.

Guidelines for the management of mature T-cell and NK-cell neoplasms (excluding cutaneous T-cell lymphoma)

The peripheral T-cell neoplasms are a biologically and clinically heterogeneous group of rare disorders that result from clonal proliferation of mature post-thymic lymphocytes. Natural killer (NK) cell neoplasms are included in this group. The World Health Organization classification of haemopoietic malignancies has divided this group of disorders into those with predominantly leukaemic (disseminated), nodal, extra-nodal or cutaneous presentation. They usually affect adults and are more commonly reported in males than in females. The median age at diagnosis is 61 years with a range of 17-90 years. Although some subtypes may follow a relatively benign protracted course most have an aggressive clinical behaviour and poor prognosis. Excluding anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL), which has a good outcome, 5-year survival for other nodal and extranodal T-cell lymphomas is about 30%. Most patients present with unfavourable international prognostic index scores (>3) and poor performance status. The rarity of these diseases and the lack of randomized trials mean that there is no consensus about optimal therapy for T- and NK-cell neoplasms and recommendations in this guideline are therefore based on small case series, phase II trials and expert opinion.

Hepatosplenic T-cell lymphoma and inflammatory bowel disease

OBJECTIVE

This article reviews the current literature and knowledge about hepatosplenic T-cell lymphoma (HSTCL), providing an overview of the clinical features, a description of its pathology and immunophenotypic traits in relation to other lymphomas. In addition, we explore the history of reported cases of hepatosplenic T-cell lymphoma in relation to the possible existence of a causal relationship between infliximab use and HSTCL. The treatments for HSTCL will be briefly addressed.

METHODS

A comprehensive literature search using multiple databases was performed. Keyword search phrases including "lymphoma," "hepatosplenic T-cell lymphoma," "Inflammatory bowel disease," "6-mercaptopurine," and "infliximab" were used in various combinations. In addition references from published papers were reviewed as well.

RESULTS

There are over 200 reported cases of HSTCL. Only 22 cases of hepatosplenic T-cell lymphoma are associated with IBD treatment. Clinicians usually reserve immunomodulators and biologics for moderate to severe IBD cases. The ultimate goal of therapy is to control inflammation and therefore allow mucosal healing. IBD patients demonstrating mucosal healing are less likely to undergo surgery and experience complications related to their disease. We manipulate the immune system with corticosteroids, immunomodulators, and biologics, therefore causing bone marrow suppression. With bone marrow suppression, malignant degeneration may begin through selective uncontrolled cell proliferation, initiating HSTCL development in the genetically susceptible.

CONCLUSION

Hepatosplenic T-cell lymphoma is a rare disease, often with a poor outcome. With the increasing number of reported cases of HSTCL linked to the use of infliximab, adalimumab, and AZA/6-MP, there appears to be an undeniable association of HSTCL development with the use of these agents. This risk is unquantifiable. When considering the rarity of cases and the multiple complications with uncontrolled disease, however, the benefit of treatment far outweighs the risk.

Gamma-delta T-cell lymphomas

Peripheral T-cell lymphomas (TCLs) are uncommon neoplasms, accounting for about 12% of all lymphoid tumors worldwide. TCLs in which gammadelta T-cell receptors are expressed (gammadelta TCLs) are extremely aggressive and rare (<1% of lymphoid neoplasms). gammadelta TCLs originate from gammadelta T cells, a small subset of peripheral T cells with direct antigen recognition capability acting at the interface between innate and adaptive immunity. Two distinct gammadelta TCL entities are recognized: hepatosplenic T-cell lymphoma (HSTL) and primary cutaneous gammadelta T-cell lymphoma (PCGD-TCL). HSTL is a well-characterized extranodal lymphoma that has a disguised onset, secondary to intrasinusoidal infiltration of the spleen, liver and bone marrow, has a rapidly progressive course that is poorly responsive to chemotherapy, and often ensues in the setting of immune system suppression. PCGD-TCL can present with prominent epidermal involvement or with a panniculitis-like clinical picture that can be complicated by a concurrent hemophagocytic syndrome; the disease shows biological and phenotypic overlap with other extranodal gammadelta TCLs that involve the respiratory or gastrointestinal tract mucosa. The regular application of phenotypic and molecular techniques is crucial for the diagnosis of gammadelta TCLs. In this Review, we discuss the clinical and biological features, the diagnostic challenges and the therapeutic perspectives of HSTL and PCGD-TCL.

Hepatosplenic T-cell lymphoma in a patient with Crohn's disease

BACKGROUND

A 58-year-old man who had a 35-year history of Crohn's disease presented to our IBD center with a disease flare, pararectal fistulas and abscess formation. The patient had previously undergone ileocolic resection for a stenosis and his abscesses had been treated by surgical drainage. He had been taking azathioprine therapy for approximately 5.5 years and had received high-dose steroids. He had also previously taken metronidazole and antihypertensive medications.

INVESTIGATIONS

Physical examination, laboratory investigations including hemoglobin levels and white blood cell counts, genetic testing, CT, bone-marrow biopsy, immunophenotyping by fluorescence-activated cell sorting, polymerase chain reaction analyses, fluorescence in situ hybridization, sputum culture and diagnostic splenectomy.

DIAGNOSIS

Hepatosplenic T-cell lymphoma.

MANAGEMENT

Splenectomy, antibiotic therapy and chemotherapy with cyclophosphamide.

Hepatosplenic and other gammadelta T-cell lymphomas

The 2005 Society for Hematopathology/European Association for Haematopathology Workshop session 11 was dedicated to hepatosplenic T-cell lymphoma (HSTCL). HSTCL is a rare aggressive type of extranodal lymphoma characterized by hepatosplenomegaly, bone marrow involvement, and peripheral blood cytopenias. HSTCL exhibits a distinctive pattern of infiltration; tumor cells preferentially infiltrate the sinusoids of the splenic red pulp, liver, and bone marrow. The tumor cells have a nonactivated cytotoxic T-cell immunophenotype and frequently carry a recurrent cytogenetic abnormality, isochromosome 7q. Most cases express the gammadelta T-cell receptor, but cases can have an alphabeta phenotype and are considered to be a variant of the disease. Although HSTCL is the prototype peripheral T-cell lymphoma expressing the gammadelta T-cell receptor, non-HSTCL proliferations of gammadelta T cells can involve other extranodal sites, mainly skin and mucosa. These gammadelta T-cell lymphomas display marked heterogeneity in clinical and histologic features. In contrast with HSTCL, non-HSTCL gammadelta T-cell lymphomas frequently have an activated cytotoxic phenotype and most likely are not a single disease entity.

Non-Hodgkin's lymphoma involving the liver: clinical and therapeutic considerations

Primary hepatic non-Hodgkin's lymphoma (NHL) is a rare disease that presents unique diagnostic and therapeutic challenges. Secondary liver involvement by lymphoma is common and can complicate treatment decisions. A review of the published case reports and the few larger series suggests that primary hepatic NHL represents a heterogeneous mixture of disparate diseases rather than a single entity. Presentations vary from the incidental discovery of hepatic abnormalities in an otherwise asymptomatic patient to that of fulminant hepatic failure with rapid progression of encephalopathy to coma and death. The clinical, laboratory, and radiographic characteristics are nonspecific, which means the diagnosis is often not suspected until histopathologic examination of liver tissue. There appears to be a strong association between primary hepatic NHL and the hepatitis C virus. Hepatosplenic T-cell lymphoma has attained its own status as a unique disease, whereas case reports suggest that the spectrum of hepatic lymphoma includes many histologies. Involvement of the liver by lymphoma can compound the difficulty of pursuing aggressive chemotherapy in patients who have a life-threatening illness and impaired metabolism of the most effective drugs. Therapy should be tailored to the individual clinical situation, with consideration of the underlying histology and degree of hepatic insufficiency.

CD26 expression correlates with a reduced sensitivity to 2'-deoxycoformycin-induced growth inhibition and apoptosis in T-cell leukemia/lymphomas

PURPOSE AND EXPERIMENTAL DESIGN

dCF (2'-deoxycoformycin) is a potent inhibitor of ADA (adenosine deaminase), an enzyme regulating intra- and extracellular concentrations of purine metabolites. ADA exists as cytosolic and extracellular forms, the latter colocalized on the cell surface with CD26. Once the surface expression of CD26 and ADA in a panel of cell lines and primary samples of T-cell leukemia/lymphoma was defined, we correlated this expression with the antiproliferative and apoptotic effect of dCF.

RESULTS

Surface expression of CD26 inversely correlated with the capability of dCF to inhibit cell growth and induce apoptosis both in T-cell lines and primary samples of T-cell malignancies. This conclusion was sustained by a decreased sensitivity to dCF-mediated proapoptotic and/or antiproliferative in vitro effects of: (a) leukemia/lymphoma T-cell lines expressing surface CD26/ADA complex; (b) primary CD26(+) T cell malignancies; and (c) normal T cells (CD26(+)) as compared with tumor T cells (CD26(-)) in unpurified samples from three cases of T-cell receptor gammadelta(+) T-cell malignancies characterized by a mixture of normal and neoplastic cells. This latter point was confirmed in vivo, in a patient affected by CD26(-) T-cell receptor gammadelta(+) hepatosplenic gammadelta(+) T-cell lymphomas treated on a compassionate basis with dCF. The inverse correlation between CD26 expression and sensitivity to dCF was also demonstrated in a lymphoblastic lymphoma case in which CD26 was expressed on circulating blasts at relapse but not at diagnosis, as well as in two H9 T-cell clones expressing or not expressing CD26 mRNA and protein.

CONCLUSIONS

This study corroborates the notion of CD26 as a marker of poor prognosis for T-cell malignancies and delineates a role for CD26 as a predictor of poor response to dCF.

Gamma/delta T cell lymphoma

A 54-year-old woman complained of fever and hepato-splenomegaly. The pathological findings of a liver biopsy specimen revealed the infiltration of lymphocytes in the sinusoids and that of the laparoscopically resected spleen revealed the infiltration of lymphocytes in the red pulp, which was positive for CD3, CD43, CD45RO and T-cell intracellular antigen-1 (TIA-1) and was negative for betaF1, while the white pulp was spared. Genetic analysis of the spleen cells revealed the rearrangement of T-cell receptor (TCR) Cbeta1, Jdelta1 and Jgamma. Epstein-Barr virus (EBV) genomic DNA was detected in the spleen cells. Atypical lymphocytes appeared in the peripheral blood and bone marrow, chromosomal analysis revealed del (13) (q12 q14), trisomy 8 and breakage of RB gene. Elevated level of serum vascular endothelial growth factor (VEGF) was observed. Hepatosplenic gammadelta T cell lymphoma (GDTL) was diagnosed. The patient was treated with chemotherapy by cyclophosphamide, hydroxydoxorubicin, vincristine and prednisolone (CHOP), however, it was ineffective, and the patient died of hemorrhage from the lymphoma involvement of the intestine 5 months after the onset of disease.

Gammadelta T-cell lymphomas

T-cell lymphomas expressing the gammadelta T-cell receptor (TCR) are uncommon, although their frequency may be underestimated. They show a broad clinicopathological spectrum. Besides precursor T-cell lymphoblastic leukemia/lymphoma, various post-thymic gammadelta T-cell neoplasms have been recognized. Among these, hepatosplenic gammadelta T-cell lymphoma constitutes the prototype of T-cell lymphomas expressing the gammadelta TCR and was listed as a provisional entity in the Revised European-American Lymphoma (REAL) classification. The recognition of this lymphoma subtype was further supported by the demonstration that the neoplasm results from a proliferation of nonactivated cytotoxic T cells and is associated with a recurrent cytogenetic abnormality, the isochromosome 7q. More recently, a few cases of hepatosplenic T-cell lymphoma with similar clinicopathologic features and alphabeta phenotype have been described that are thought to belong to the same entity, and the term "hepatosplenic T-cell lymphoma" is preferred in the current World Health Organization (WHO) classification. Most nonhepatosplenic gammadelta T-cell lymphomas occur in skin or in mucosal sites, a location that parallels that of normal gammadelta T cells. In contrast to hepatosplenic gammadelta T-cell lymphomas, they show an important clinical and morphological heterogeneity, have an activated cytotoxic phenotype, and are not believed to constitute a single disease entity.

Enantiospecific synthesis of carbapentostatins

In this paper we describe enantioselective syntheses of (+)-carbapentostatin (8) and its cyclopentyl analogue 12b. A new and efficient one-pot, two-step preparation of aldehyde 15 has been developed, based on the borane reduction of N-Pf-protected L-aspartic acid gamma-methyl ester (13) and Swern oxidation of the resulting alcohol. Homologation to diester 18 and ring formation by Dieckman cyclization, followed by reduction and dehydration steps, afford the 4-amino-1-cyclopentenemethanol derivative 22. Hydroboration and oxidation transform this compound stereospecifically into aminocyclopentanol 26, the key aminocyclitol component for an asymmetric synthesis of (+)-carbapentostatin.

CD4-CD8-"Double-negative" cutaneous T-cell lymphomas share common histologic features and an aggressive clinical course

We report 15 patients with CD4-CD8-"double-negative" T-cell lymphoma arising in skin. There were seven women and eight men with a mean age at diagnosis of 53 years (range 19-77 years). All but two patients presented with solitary or multiple cutaneous nodule(s). Initial and recurrent biopsy specimens showed a dense infiltrate centered in the mid-dermis (extending into subcutis when sampled) of small to intermediate-sized lymphocytes with indistinct nucleoli and frequently irregular nuclear contours. Periadnexal infiltration and epidermal ulceration were present in five cases with the intraepidermal cells being primarily reactive CD4+ T cells. All cases were negative for CD30 and terminal deoxynucleotidyltransferase; one showed expression of CD56, and six of eight tested cases were positive for T-cell receptor-delta expression. Despite systemic chemotherapy, all 12 patients with clinical follow-up showed recurrent or progressive disease with widespread cutaneous dissemination in 10 of 12. Eventual dissemination to lymph nodes or bone marrow occurred in two patients each, with at least nine patients dead of disease or treatment complications. Only two patients achieved lasting clinical remission (with 2'-deoxycoformycin/pentostatin and nelarabine, respectively). CD4-CD8-"double-negative" CTCL has distinctive histologic features and cytomorphology with a marked propensity for rapid multifocal cutaneous dissemination.

2'-Deoxycoformycin for hepatosplenic gammadelta T-cell lymphoma

We describe a patient with unusually indolent hepatosplenic gammadelta T cell lymphoma characterised by severe lassitude and high fever. No significant responses were obtained to a range of chemotherapeutic and biological agents. 2'-deoxycoformycin (dCF), however, produced a dramatic and sustained clinical and histological response. This is the second recent report of gammadelta T cell lymphoma responding to dCF, suggesting this agent may have a specific role in this condition.