Immune escape mechanisms in ALCL

Tumor microenvironment and immune effects of antineoplastic therapy in lymphoproliferative syndromes

Lymphomas represent a wide group of heterogenic diseases with different biological and clinical behavior. The underlying microenvironment-specific composition seems to play an essential role in this scenario, harboring the ability to develop successful immune responses or, on the contrary, leading to immune evasion and even promotion of tumor growth. Depending on surrounding lymphoid infiltrates, lymphomas may have different prognosis. Moreover, recent evidences have emerged that confer a significant impact of main lymphoma's treatment over microenvironment, with clinical consequences. In this review, we summarize these concepts from a pathological and clinical perspective. Also, the state of the art of lymphoma's anti-idiotype vaccine development is revised, highlighting the situations where this strategy has proven to be successful and eventual clues to obtain better results in the future.

Differences in survivin location and Bcl-2 expression in CD30+ lymphoproliferative disorders of the skin compared with systemic anaplastic large cell lymphomas: an immunohistochemical study

BACKGROUND

Cutaneous CD30+ lymphoproliferative disorders (LPDs) are a spectrum of disease associated with a favourable prognosis. Systemic anaplastic large cell lymphoma (ALCL), although morphologically and phenotypically similar, differs in clinical presentation and has a less favourable biological behaviour. Dysregulation of apoptosis, the process regulating cell population by programmed death, can explain the differences among these disorders.

OBJECTIVES

We investigated the expression of two inhibitors of apoptosis, survivin and Bcl-2 protein, in serial skin lesion samples from CD30+ LPDs compared with systemic ALCL.

METHODS

Immunohistochemical analysis with antibodies against anaplastic lymphoma kinase (ALK)-1 protein, survivin and Bcl-2 protein was performed in 10 cutaneous CD30+ LPDs (five lymphomatoid papulosis, five ALCL) and 18 systemic ALCLs. Reverse transcription-polymerase chain reaction studies for ALK and ALK/nucleophosmin were also performed.

RESULTS

Cutaneous CD30+ LPDs shared a heterogeneous expression of cytoplasmic survivin with all systemic ALCLs, and of Bcl-2 with systemic ALK- ALCLs; however, they differ from systemic ALK- ALCLs because they lack nuclear survivin (P = 0.045), and from systemic ALK+ ALCLs by a higher expression of Bcl-2 (P = 0.045) and a lack of ALK-1. Overall, coexpression of Bcl-2 and nuclear survivin in CD30+ LPDs was associated with a less favourable disease survival.

CONCLUSIONS

The different patterns of expression of Bcl-2 and survivin in CD30+ LPDs might have an impact on their different biological and clinical behaviour. Moreover, nuclear localization of survivin, similarly to ALK, may be a useful marker for predicting a systemic form of ALCL with cutaneous presentation.

Apoptosis resistance and response to chemotherapy in primary nodal diffuse large B-cell lymphoma

Diffuse large B-cell lymphomas (DLBCL) represent the most common type of adult malignant lymphoma in western countries and are treated with high dose combination chemotherapy. Although initially the majority of patients respond to this therapy, many do not achieve complete remission and others experience an early relapse. Several studies have shown that prediction of the clinical response to chemotherapy is possible before the start of chemotherapy treatment. Apparently, DLBCL are intrinsically either resistant or sensitive to chemotherapy-induced cell death. Differences in functional integrity of the apoptosis cascade are an important factor predicting outcome in DLBCL. In this review we discuss the possible mechanisms leading to intrinsic resistance to apoptosis and provide an explanation why strong differences in apoptosis sensitivity between DLBCL are observed. Subsequently we will focus on how differences in this intrinsic apoptosis resistance provide an explanation for the variable response to combination chemotherapy and how this can be used for further therapy tailoring.

Coexpression of major histocompatibility complex class I and LMP1 in Epstein-Barr virus-positive Hodgkin'sLymphoma in a pediatric age group

The Epstein-Barr virus (EBV)-encoded latent membrane proteins (LMP1 and LMP2) are consistently expressed by malignant Hodgkin Reed-Sternberg (HRS) cells of EBV-associated Hodgkin's disease (HD). The EBV LMP1 has been implicated in tumorogenesis. Cytotoxic T lymphocyte (CTL) responses to both of these proteins have been shown in the blood of EBV-seropositive individuals, and in HD, the apparent failure of the CTL response to eliminate HRS cells expressing LMP1 in vivo has given rise to the suggestion that HD may be characterized by the presence of defects in antigen CTL-presentation or in CTL dysfunction. This study examined 28 cases seen at the Regional Children's Hospital Arturo Grullón in Santiago, the Dominican Republic, by immunohistochemistry. High level of expression of major histocompatibility complex (MHC) class I molecules in HRS cells of EBV-associated HD was recorded. These results suggest that deregulation of MHC class I molecules does not account for the apparent ability of EBV to infect HRS cells and to evade CTL protection. Therefore, the result from our work and similar studies will help to determine whether, or which, immunotherapy should be used in positive and negative cases of HD related to EBV.