Epstein-Barr virus, B cells, T cells, and a lymphoproliferative disorder

Management of Angioimmunoblastic T-Cell Lymphoma (AITL) and other T Follicular Helper Cell lymphomas (TFH PTCL)

Despite the remarkable improvements in the treatment and outcome of patients with aggressive B-cell lymphoma, the peripheral T-cell lymphomas (PTCL) continue to carry a poor prognosis with the presently available treatment options. The PTCL are very rare diseases that account for only 10,000 to 15,000 new cases per year in the United States. The World Health Organization's 2016 classification describes 29 distinct subtypes of PTCL, thus making these both rate and incredibly heterogenous. The 2 most common forms of PTCL, for example, peripheral T-cell lymphoma-not otherwise specified and angioimmunoblastic T-cell lymphoma , have an incidence of only 2500 and 1800 cases per year respectively, in the United States.

Epstein-Barr virus-associated B-cell lymphoproliferative disorders in angloimmunoblastic T-cell lymphoma and peripheral T-cell lymphoma, unspecified

Various patterns of Epstein-Barr virus (EBV)-associated B-cell lymphoproliferation occur in patients with immunodeficiency. We studied 17 cases of T-cell lymphoma displaying extensive EBV-driven B-cell lymphoproliferation or simultaneous/subsequent EBV-associated B-cell lymphoma. In 10 cases of angioimmunoblastic T-cell lymphoma, an uncommonly prominent population of EBV+ atypical, activated, focally confluent large transformed B cells was found in the background of T-cell lymphoma. In 4 cases, an EBV-associated B-cell neoplasm (3 diffuse large B-cell lymphomas, 1 plasmacytoma) occurred in patients with T-cell lymphoma. Three cases were composite lymphomas of a peripheral T-cell lymphoma, unspecified, combined with EBV-associated diffuse large B-cell lymphoma. The transformed B-cell population displayed EBV latency types 2 and 3. Monoclonal and oligoclonal B-cell populations were detected in 5 and 6 cases, respectively. Similar to other states of immunodeficiency, disease-related and therapy-induced immunosuppression in T-cell lymphoma may lead to a prominent EBV-associated B-cell lymphoproliferation and to EBV+ B-cell neoplasms.

Epstein-Barr virus-negative Hodgkin's lymphoma after mycosis fungoides: molecular evidence for distinct clonal origin

The association of mycosis fungoides (MF) and Hodgkin's lymphoma is a relatively frequent occurrence, but the potential clonal relationship of the two neoplasms is still controversial. We report a case of a patient with a history of MF in Clinical Stage 1A who developed retroperitoneal lymphadenopathy 9 years after the initial diagnosis of MF. A bone marrow biopsy obtained at this time showed nodular involvement by a mixed cellular infiltrate with large, atypical cells consistent with Hodgkin and Reed-Sternberg (RS) cells. These atypical cells were positive for CD30 and CD15 and did not express B- or T-cell markers. In addition, they lacked evidence of infection by Epstein-Barr virus, both by immunohistochemical staining for latent membrane protein 1 and by in situ hybridization for EBER1/2. The background population consisted mainly of small T cells without morphological or phenotypical signs of malignancy. Review of the skin biopsy obtained 9 years before showed the typical features of MF. Polymerase chain reaction analysis of the T-cell receptor T-gene confirmed the presence of a clonal T-cell rearrangement in the skin specimen. The bone marrow biopsy, however, showed a polyclonal pattern both for the T-cell receptor gamma-gene, as well as for immunoglobulin heavy chain genes. Isolation of RS cells stained for CD30 was performed by laser capture microdissection. Polymerase chain reaction analysis of several groups of RS cells showed a reproducible biallelic rearrangement of IgH genes, which was confirmed by cloning and sequencing of polymerase chain reaction products. To our knowledge, this is the first case in which a distinct clonal origin of MF and Hodgkin's lymphoma arising in the same patient is clearly demonstrated, based on molecular analysis of microdissected RS cells.

Peripheral T-cell lymphoma with Reed-Sternberg-like cells of B-cell phenotype and genotype associated with Epstein-Barr virus infection

We report three cases of nodal peripheral T-cell lymphoma (PTCL) with Reed-Sternberg-like (RS-like) cells of B-cell pheno- and/or genotype. Histologic analysis in all cases revealed diffuse nodal effacement by atypical lymphoid cells of variable size. Two of the three cases had features of angioimmunoblastic T-cell lymphoma (AILT). Large mononuclear and binucleated cells with prominent eosinophilic nucleoli and abundant cytoplasm resembling classic RS cells and mononuclear variants were scattered throughout all biopsies. The lymphoma cells in the three cases were of T-cell lineage (CD3+, CD43+, and CD45RO+). The RS-like cells from all cases were CD30 and CD15 positive. In contrast to the neoplastic T cells, the RS-like cells lacked all T-cell markers and in two cases were positive for CD20. Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) and EBER 1 (2/2) were detected in the RS-like cells in all cases. The neoplastic T cells were negative for EBV. Polymerase chain reaction (PCR) analysis demonstrated clonal rearrangements of the T-cell receptor gamma chain gene in the three cases. PCR analysis of microdissected RS-like cells for immunoglobulin heavy chain gene rearrangements in cases 1 and 3 showed an oligoclonal pattern. The presence of RS-like cells in PTCL represents a diagnostic pitfall, because in one case this observation led to a misdiagnosis of Hodgkin's disease (HD). The oligoclonal expansion of EBV-infected cells may be related to underlying immunodeficiency associated with T-cell lymphomas and AILT in particular. This phenomenon may provide the basis for some cases of Hodgkin's disease after T-cell lymphomas and suggests that they are clonally unrelated neoplasms. The expression of LMP1 appears to be crucial for the immunophenotype and probably for the morphology of the RS and RS-like cells appearing in diverse lymphoid malignancies, including HD, chronic lymphocytic leukemia, and PTCL.

Epstein-Barr virus genomes in Hodgkin's disease and non-Hodgkin's lymphomas

Seventeen of 40 cases of Hodgkin's disease (HD) and eight of 46 non-Hodgkin's lymphomas (NHL) were associated with Epstein-Barr virus (EBV) infection, judged by the EBER-1 in situ hybridization (ISH) method. Approximately 40% incidence in HD was comparable to previous reports. Young children and elderly HD patients were more prone to be found EBV positive. Fourteen of 17 HD and two of 8 NHL cases with positive EBER-1 ISH were also positive on LMP-1 immunostaining. EBV might have a role in lymphomagenesis in these cases. The fact that 7 of 8 EBV-related NHL were peripheral T cell lymphoma indicates the necessity of a larger-scale survey on this subject. As the present study revealed four cases with positive LMP-1 immunostaining but negative EBER-1 ISH (1 HD, 3 NHL), LMP-1 alone should not be regarded as a tool to prove EBV infection.