Correlation of T-cell immune response with spontaneous resolution and subsequent relapse of Hodgkin's lymphoma

Spontaneous Regression of Hodgkin Lymphoma: Case Report and Review of the Literature

Spontaneous regression of Hodgkin lymphoma (HL) is a rare event. We describe a 32-year-old woman with spontaneous regression of HL and review the literature. The patient presented with cervical lymphadenopathy and was diagnosed with stage IIA classical HL. The patient refused to receive any treatment for her disease. Positron emission tomography/computed tomography carried out 2 years later showed complete regression of the lymphadenopathy, without pathological uptake of fluorodeoxyglucose. At the last follow-up, 3.5 years after the initial presentation, the patient is with no evidence of disease. During workup for the HL, concomitant papillary thyroid carcinoma was diagnosed, for which the patient refused treatment as well. The thyroid malignancy has remained stable throughout the follow-up.

T-Cell Traffic Jam in Hodgkin's Lymphoma: Pathogenetic and Therapeutic Implications

In hematologic malignancies, the microenvironment is often characterized by nonneoplastic cells with peculiar phenotypic and functional features. This is particularly true in Hodgkin's lymphoma (HL), in which T lymphocytes surrounding Hodgkin's Reed-Sternberg cells are essentially polarized towards a memory T-helper type 2 phenotype. In this paper we will first evaluate the main processes modulating T-cell recruitment towards the lymph node microenvironment in HL, especially focusing on the role played by cytokines. We will then consider the most relevant mechanisms of immune escape exerted by neoplastic cells in order to evade antitumor immunity. The potential pathogenetic and prognostic impact of regulatory T cells in such a context will be also described. We will finally overview some of the strategies of cellular immunotherapy applied in patients with HL.

The interplay between Epstein-Barr virus and the immune system: a rationale for adoptive cell therapy of EBV-related disorders

The Epstein-Barr virus has evolved a plethora of strategies to evade immune system recognition and to establish latent infection in memory B cells, where the virus resides lifelong without any consequence in the majority of individuals. However, some imbalances in the equilibrium between the inherent virus transforming properties and the host immune system can lead to the development of different tumors, such as lymphoproliferative disorders, Hodgkin's lymphoma, Burkitt's lymphoma, and nasopharyngeal carcinoma. The expression of viral antigens in malignant cells makes them suitable targets for immunotherapeutic approaches, which are mainly based on the ex vivo expansion of EBV-specific T cells. Indeed, the infusion of virus-specific cytotoxic T lymphocytes has proved not only to be safe and effective, but also capable of restoring or inducing a protective anti-virus immunity, which is lacking, albeit to a different extent, in every EBV-driven malignancy. The purpose of this review is to summarize the results of adoptive immunotherapy approaches for EBV-related malignancies, with particular emphasis on the immunological and virological aspects linked to the clinical responses obtained. Data collected confirm the clinical relevance of the use of EBV-specific cytotoxic T lymphocytes in the field of adoptive immunotherapy and suggest the increasing importance of this approach also against other tumors, concurrent with the increasing knowledge of the intimate and continuous interplay between the virus and the host immune system.

Regulatory T cells and EBV associated malignancies

It has been shown that the T-regulatory cells (Tregs) not only play a key role in the establishment and maintenance of peripheral tolerance to prevent the autoimmune disease, but also inhibit the anti-tumor immunity. Recently, many studies have demonstrated that cytotoxicity T cells (CTL) can control the growth of EBV-positive tumor cells in vitro, including Hodgkin's lymphoma (HL), nasopharyngeal carcinoma, posttransplantation lymphoproliferative disorders (PTLD), depending on the large mount of EBV antigens presented by MHC molecules on the surface of these malignant cells. However, limited benefit of CTL adoptive immunotherapy has been reported in the treatment of EBV positive HL and NPC, and Tregs are regarded as a critical hurdle in this issue. In the present review, we discuss the correlation of EBV antigens expression in the tumor cells and the induction of Tregs in tumor microenvironment. Treg subsets and its possible mechanism to attenuate the anti-tumor immunity in EBV associated malignancies are also discussed, following by the possible strategies of targeting Tregs in the future immunotherapy for EBV positive cancers.

Spontaneous regression of an EBV-associated monoclonal large B cell proliferation in the mastoid of a young child following surgical biopsy

We report the spontaneous regression of an Epstein-Barr virus-associated monoclonal lymphoid proliferation in an immunocompetent child. A 2-year-old male with acute otitis media presented with a right-sided facial palsy secondary to acute mastoiditis. During mastoid decompression a polypoid mass, a histologically diffuse large B cell lymphoma, was found. Staging revealed localized disease. At surgical re-exploration 5 weeks later the disease had resolved. Retrospective serological testing was consistent with an acute Epstein-Barr viral infection and in situ hybridization of the tumour tissue was positive for Epstein-Barr RNA.

Detection of T-regulatory cells has a potential role in the diagnosis of classical Hodgkin lymphoma

Previous studies have demonstrated an increase in T-regulatory cells in the involved lymph nodes and peripheral blood of patients with Hodgkin lymphoma. Our study examined whether the detection of T-regulatory cells by flow cytometry could distinguish classical Hodgkin lymphoma (CHL) from benign cases and B-cell non-Hodgkin lymphomas (B-NHL). We measured CD4, CD25, and CD152 in 14 CHLs, 2 nodular lymphocyte-predominant Hodgkin lymphomas, 31 B-NHLs, and 54 benign cases. All T-regulatory cell parameters, including percent lymphocytes CD4+/CD152+ and CD4+/CD25+/CD152+, and mean and median CD152 expression in CD4+/CD25+ lymphocytes, were higher in CHL than in B-NHL and benign. Mean CD152 in CD4+/CD25+ lymphocytes distinguished CHL from benign with 79% sensitivity and 100% specificity, and from B-NHL with 71% sensitivity and 90% specificity. Overall, our results show that T-regulatory cells are increased in CHL and their detection may be a useful tool in differentiating CHL from other entities.