The role of hematopoietic stem-cell transplantation in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma represents a broad spectrum of disorders with various manifestations, clinical courses, and therapeutic considerations. Mycosis fungoides is the most common form of cutaneous T-cell lymphoma, the skin being affected by erythematous patches, plaques, or tumors. The related Sézary syndrome is a more aggressive form of cutaneous T-cell lymphoma with cutaneous and leukemic manifestations. Recent advances in the understanding of the molecular and biologic behavior of T cells in these disorders have facilitated the development of novel treatments, using biologic agents, phototherapeutic methods, and irradiation techniques. Nevertheless, there remains a continued need to develop new therapeutic options, particularly for patients with advanced-stage and treatment-refractory disease. At present, hematopoietic stem-cell transplantation has the best chance for expanding the therapeutic armamentarium of cutaneous T-cell lymphoma. In advanced-stage mycosis fungoides and the Sézary syndrome, stem cell transplantation may result in sustained remissions and improvement of progression-free survival. However, physicians have to be aware of severe clinical problems like graft-versus-host disease as well as increased risk of infection and secondary cancers. In this review, we focus on the role of hematopoietic stem cell transplantation for the therapy of mycosis fungoides and the Sézary syndrome.

Pruritus in cutaneous T-cell lymphomas: frequent, often severe and difficult to treat

Pruritus has a well-known association with Hodgkin's disease and other nodal lymphomas; indeed it often reveals the disease. Pruritus is also an important symptom of cutaneous T-cell lymphomas. Lymphoma-associated itch is thus both frequent and severe, but its pathophysiology remains unclear. Few studies have evaluated the efficacy of therapeutic agents in the management of cutaneous T-cell lymphoma-related pruritus. The main objective of treatment remains disease control. Pruritus management is generally based on the physician's experience. Treatment is very difficult, especially in Sézary syndrome. We present here management strategies for cutaneous lymphoma-associated pruritus.

Clinical outcome of patients with subcutaneous panniculitis-like T-cell lymphoma

Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of cytotoxic T-cell lymphoma. The objective of this study was to characterize the clinical presentation, treatment, and prognosis of patients with SPTCL. Twenty-one patients with SPTCL were seen at Mayo Clinic (Rochester, Minnesota, USA) between July 1973 and June 2004. The median age at diagnosis was 42 years (range 23-80 years) and 15 (71%) were women. Constitutional symptoms occurred in 14 (67%) patients, including fever, serositis, arthralgias and myalgias. The Eastern Cooperative Oncology Group performance score was poor (3-4) in 3 (15%) patients. Liver enzymes (at least 2 enzymes, Aspartate aminotransferase (AST), alkaline phosphatase and/or lactate dehydrogenase) were elevated in 11 (52%) patients. Therapy consisted of chemotherapy in 13 (62%) patients, or other therapeutic interventions in 8 (38%) patients, including surgical excision, corticosteroids alone or in combination with either plaquenil, colchicine, hydroxychoroquine, or azathioprine. Bone marrow transplantation was performed in 5 (24%) patients, 3 autologous and 2 allogeneic. The median overall survival from diagnosis was 15 months (range 0.1-104 months). Two groups of patients were identified and categorized as having a favorable or unfavorable disease course. The factors associated with an unfavorable disease course were a low white blood cell count or elevated lactate dehydrogenase. Patients treated aggressively with stem cell transplantation appeared to have an improved overall survival.

Cutaneous T-Cell Lymphoma: A Paradigm for Biological Therapies

Mycosis Fungoides and Sézary Syndrome are the most common types of cutaneous T-cell lymphomas. There is no current standard of care for Mycosis Fungoides/Sézary Syndrome, with a general tendency to rely on topical interventions for early disease delaying systemic, more toxic therapy until the development of extensive symptoms. Knowledge of the biological characteristics of this disease has allowed for the development of rational interventions and a significant advance in its treatment. Retinoids are active in Mycosis Fungoides/Sézary Syndrome with the newer rexinoids being available in topical and systemic forms. Interferon alpha remains one of the most active therapeutic agents for Mycosis Fungoides/Sézary Syndrome, especially in combination with other agents such as PUVA. The monoclonal antibody alemtuzumab leads to responses in at least half of patients with advanced disease with its side effect profile consisting mainly of immunosupression and infusion reactions. The recombinant IL2-diphteria toxin denileukin diftitox (Ontak) is active in this disease and appears to have a beneficial effect in symptoms relief and quality of life. Extracorporeal photochemotherapy as an immunostimulating intervention seems to be very effective in a subset of patients, but its availability is limited to less than a hundred centers worldwide. Experimental and less studied interventions include autologous and allogeneic peripheral stem cell transplantation, Interleukin-12, the histone-deacetylator depsipeptide and the synthetic deoxynucleotide CpG7909. Cutaneous T-cell lymphoma has served as a paradigm for the development of biological agents. Further knowledge of the signaling pathways in Mycosis Fungoides/Sézary Syndrome will allow for the development of more effective treatment strategies.

Defucosylated anti-CCR4 monoclonal antibody exercises potent ADCC-mediated antitumor effect in the novel tumor-bearing humanized NOD/Shi-scid, IL-2Rgamma(null) mouse model

PURPOSE

There are no suitable small animal models to evaluate human antibody-dependent cellular cytotoxicity (ADCC) in vivo, due to species incompatibilities. Thus, the first aim of this study was to establish a human tumor-bearing mouse model in which human immune cells can engraft and mediate ADCC, but where the endogenous mouse immune cells cannot mediate ADCC. The second aim was to evaluate ADCC mediated in these humanized mice by the defucosylated anti-CC chemokine receptor 4 (CCR4) monoclonal antibody (mAb) which we have developed and which is now in phase I clinical trials.

EXPERIMENTAL DESIGN

NOD/Shi-scid, IL-2Rgamma(null) (NOG) mice were the recipients of human immune cells, and CCR4-expressing Hodgkin lymphoma (HL) and cutaneous T-cell lymphoma (CTCL) cell lines were used as target tumors.

RESULTS

Humanized mice have been established using NOG mice. The chimeric defucosylated anti-CCR4 mAb KM2760 showed potent antitumor activity mediated by robust ADCC in these humanized mice bearing the HL or CTCL cell lines. KM2760 significantly increased the number of tumor-infiltrating CD56-positive NK cells which mediate ADCC, and reduced the number of tumor-infiltrating FOXP3-positive regulatory T (Treg) cells in HL-bearing humanized mice.

CONCLUSIONS

Anti-CCR4 mAb could be an ideal treatment modality for many different cancers, not only to directly kill CCR4-expressing tumor cells, but also to overcome the suppressive effect of Treg cells on the host immune response to tumor cells. In addition, using our humanized mice, we can perform the appropriate preclinical evaluation of many types of antibody based immunotherapy.

Cutaneous T cell lymphoma-mycosis fungoides and Sezary syndrome: an update

Mycosis fungoides (MF) is the most common form of cutaneous T cell lymphoma (CTCL) and, for unclear reasons, its incidence appears to be increasing. Due to significant differences in biological behavior, cutaneous T cell lymphomas have recently been reclassified. MF and Sezary syndrome (SS) are now separately classified as indolent and aggressive CTCLs, respectively. The cause of MF and SS remains elusive. Because establishing the diagnosis of MF, particularly in early stages of disease, is often difficult, a guideline with clinical and histological diagnostic criteria has recently been proposed. With the exception of very early stage disease, no cure is available. However, the number of available therapeutic options has increased considerably in recent years, and partial and complete remissions are achievable. Prognosis and selection of appropriate therapy largely depends on stage of disease. A detailed practice guideline with an algorithmic, stage-based approach to therapy has recently been put forth and will likely aid clinicians in managing patients with MF and SS. Despite the indolent nature in most individuals, the disease has a tremendous psychological impact, not only because of the visible nature of the skin lesions, but also due to the rarity of the disease and its chronicity. Knowledge of this disease, therapeutic options and expectations of therapy will greatly enhance care of afflicted patients.

Transimmunization for cutaneous T cell lymphoma: A phase I study

Extracorporeal photochemotherapy (ECP) is a widely used immunotherapy for cutaneous T cell lymphoma (CTCL). It involves four sequential steps: conversion of blood monocytes into dendritic antigen presenting cells (DC) by repetitive adherence and disadherence to plastic surface; reinfusion of the new DC; presumed in vivo loading of the new DC with apoptotic malignant leukocytes; and expansion of the anti-tumor CD8 T cell pool. To assess the safety of a methodology designed to increase ex vivo contact between the apoptotic malignant cells and new DC prior to reinfusion, a single-center, open-label Phase I clinical study of a revised procedure--referred to as "Transimmunization"--was conducted in CTCL patients. Twenty-seven subjects were treated monthly for 3 to 5 months, alone or in combination with electron beam therapy. For those receiving Transimmunization alone, there was an overall diminution in infiltrative lesions in eleven (55%) of twenty patients. In the twelve leukemic CTCL patients, there was a significant mean reduction of 50.1% in the circulating malignant cells, as determined with family-specific anti-T cell receptor Vbeta monoclonal antibodies (P <or= 0.021). Because this therapy permits the synchronous induction and tumor loading of DC, with minimal toxicity, Transimmunization may merit further investigation in CTCL and other malignancies.

[Extracorporeal photopheresis in dermatology]

Extracorporeal photochemotherapy or photopheresis is an immunomodulatory therapy that combines leukapheresis with phototherapy. Blood from the patient is processed to give a leukocyte-rich plasma, which is then treated ex vivo with a photosensitizer and ultraviolet A radiation before reinfusion back into the patient. The exact mechanism of action of photopheresis has not been fully elucidated although it is thought that induction of leukocyte apoptosis and formation of dendritic cells is essential for the development of an immune response to pathogenic cells. Extracorporeal photophoresis was initially used for treating cutaneous T-cell lymphoma. Since then, in view of its efficacy and safety, it has been used in a number of cutaneous and noncutaneous diseases with uneven results, which can in part be explained by the different patient selection criteria, therapy regimens, and follow-up protocols used in different hospitals.

Current Concepts of the Immunobiology and Immunotherapy of Cutaneous T Cell Lymphoma: Insights Gained through Cross-talk between the Clinic and the Bench

An understanding of the immunologic features of cutaneous T cell lymphoma (CTCL) has led to insights into the life cycle of the malignancy. The identification of the T cell lineage of the neoplastic CTCL cells has allowed unification of diverse clinical presentations under a single entity. The CD4 inducer T cell phenotype of the malignant cells has provided an understanding of the patient's ability to resist infection with certain bacteria. The clonality of the tumor cells, beyond its diagnostic implications, has made them a valuable resource for studying both normal and neoplastic T cell biology. The recently identified immunosuppressive features of the malignant T cells and their dependency for survival on an interaction with immature dendritic cells have explained previously cryptic clinical observations and identified new targets for immunotherapy. Future insights gained both from the bedside and the bench will provide not only an understanding of the immunobiology of the malignancy but also open new avenues for therapeutic intervention.

Primary bone lymphoma: a series from a cancer institute in Pakistan

Primary bone lymphoma (PBL) is an uncommon tumour. Numerous studies have been reported from Western countries, but none from Southeast Asia. We reviewed a series of seven consecutive patients diagnosed and treated with PBL at our hospital between March 2002 and January 2007. All patients underwent chemotherapy with half receiving radiotherapy as their initial treatment. Six (84%) patients were male and 1 (16%) female with a median age of 33 (range: 23-85). All had diffuse large B-cell lymphoma (DLBCL) of bone except one (85 - M) who had chest wall cutaneous T-cell lymphoma with iliac blade involvement. The femur was the most frequently involved site (43%). Except for three patients that involved the lymph nodes, all patients had disease limited to bone. The 5-year overall survival rate was 43%. Although the number of patients was small, the data presented here revealed several characteristics of PBL.

Granulomatous slack skin presenting as acquired ichthyosis and muscle masses

We describe a case of granulomatous slack skin in a 31-year-old woman with an unusual presentation of acquired ichthyosis and muscular masses involving four limbs over 3 years. Vesicles and ulcerative skin nodules first appeared only 3 months prior to diagnosis. The diagnosis was confirmed after sequential biopsies of muscle, skin lesions, and lymph nodes, together with molecular genetic studies. The patient responded poorly to various therapies, including thalidomide, and died of doxorubicin-related cardiomyopathy.

Extracorporeal photopheresis: Lighting the way to immunomodulation

Photopheresis, initially established as an effective treatment of cutaneous T-cell lymphoma, has in recent years also been used to treat chronic graft vs. host disease, heart transplant rejection, and several other conditions requiring immunosuppression. Despite reported beneficial results of this procedure in treatment of various conditions, randomized controlled clinical trials are lacking for the majority of suggested indications. Furthermore, the mechanisms of action of this procedure are still unclear. Deeper understanding of the molecular basis of photopheresis-based immunomodulation will allow better selection of patients to be treated and will facilitate development of novel, minimally toxic immunomodulatory treatments.

Cutaneous T cell lymphoma: translating immunobiology into therapeutic opportunities

Cutaneous T cell lymphoma (CTCL) has always served as a proving ground where conceptual advances in immunology can be tested and the results translated into clinical practice. From the earliest studies that used sheep red blood cells to identify the malignant cell as a T lymphocyte to molecular demonstration of the clonalilty of the disease, basic science techniques have provided sign posts that allow us to understand the clinical features seen in the patients. We continue to apply this paradigm to develop new insights into the role of the immune system in CTCL with the goal of using this knowledge to enhance the therapeutic options available to the patient. This article will review the studies that have led to our current understanding of the immunobiology of CTCL and the new therapeutic approaches that are being tested in this disease.

A human CD4 monoclonal antibody for the treatment of T-cell lymphoma combines inhibition of T-cell signaling by a dual mechanism with potent Fc-dependent effector activity

Zanolimumab is a human IgG1 antibody against CD4, which is in clinical development for the treatment of cutaneous and nodal T-cell lymphomas. Here, we report on its mechanisms of action. Zanolimumab was found to inhibit CD4+ T cells by combining signaling inhibition with the induction of Fc-dependent effector mechanisms. First, T-cell receptor (TCR) signal transduction is inhibited by zanolimumab through a fast, dual mechanism, which is activated within minutes. Ligation of CD4 by zanolimumab effectively inhibits early TCR signaling events but, interestingly, activates signaling through the CD4-associated tyrosine kinase p56lck. An uncoupling of p56lck from the TCR by anti-CD4 allows the kinase to transmit direct inhibitory signals via the inhibitory adaptor molecules Dok-1 and SHIP-1. Second, CD4+ T cells are killed by induction of antibody-dependent cell-mediated cytotoxicity, to which CD45RO+ cells are more sensitive than CD45RA+ cells. Finally, zanolimumab induces down-modulation of CD4 from cell surfaces via a slow Fc-dependent mechanism. In conclusion, zanolimumab rapidly inhibits T-cell signaling via a dual mechanism of action combined with potent Fc-dependent lysis of CD4+ T cells and may act long-term by down-regulating CD4.

Consequences of misdiagnosis of lymphomatoid papulosis

We report two patients with lymphomatoid papulosis (LyP), who were initially diagnosed as systemic T-cell lymphoma. The patients presented with recurrent self-healing cutaneous lesions and skin biopsies showed a lymphocytic infiltrate with malignant features. Clinico-pathological correlation of findings was not performed and results of staging investigations were misinterpreted. Consequently, both patients were unnecessarily treated with multi-agent chemotherapy, radiotherapy and stem cell/bone marrow transplants and sustained long-term adverse effects. The clinical and histological features of LyP are described and appropriate management discussed in detail. Factors leading to the unnecessary treatment of both patients are examined and several learning points highlighted such as the importance of a multidisciplinary approach.

Down-modulation of CXCR3 surface expression and function in CD8+ T cells from cutaneous T cell lymphoma patients

Viruses can escape destruction by the immune system by exploitation of the chemokine-chemokine receptor system. It is less established whether human cancers can adopt similar strategies to evade immunologic control. In this study, we show that advanced cutaneous T cell lymphoma (CTCL) is associated with selective and efficient inactivation of CXCR3-dependent T cell migration. Our studies demonstrate that this alteration is at least in part due to CXCR3 down-regulation in vivo by elevated serum levels of CXCR3 ligands. The T cell population most affected by this down-regulatory mechanism are CD8+ cytotoxic effector T cells. In CTCL patients, cytotoxic effector T cells have strongly reduced surface CXCR3 expression, accumulate in peripheral blood, but are virtually absent from CTCL tumor lesions, indicating an inability to extravasate into lymphoma tissue. CTCL-associated inactivation of effector cell recruitment may be a paradigmatic example of a new type of immune escape mechanisms shielding the neoplasm from a tumoricidal attack.

Maintenance therapy in cutaneous T-cell lymphoma: Who, when, what?

The aim of current therapy for cutaneous T-cell lymphoma (CTCL) is to induce clinically meaningful remission, provide symptom relief, improve patient quality of life (QoL) and prolong disease-free and overall survival. A key research question is whether such remissions or minimal disease status can be maintained in the long term. There have been few formal studies of maintenance therapy in CTCL. Some skin-directed therapies such as total-skin electron-beam therapy and high-dose psoralen plus ultraviolet A may not be considered suitable, because of the risk of long-term cumulative toxicities. Other therapies such as nitrogen mustard, interferon (IFN)-alpha and bexarotene have demonstrated positive effects in prolonging remissions in small numbers of patients. Large longitudinal studies are required to investigate the efficacy of maintenance treatments in CTCL and their impact on patients' QoL and overall survival. Of the systemic therapies currently approved for the treatment of CTCL, bexarotene and IFN-alpha are obvious candidates for testing, because they can be self-administered by the patient and provide good long-term tolerability.