Naturally occurring T cell mutations enhance engineered T cell therapies

Adoptive T cell therapies have produced exceptional responses in a subset of patients with cancer. However, therapeutic efficacy can be hindered by poor T cell persistence and function1. In human T cell cancers, evolution of the disease positively selects for mutations that improve fitness of T cells in challenging situations analogous to those faced by therapeutic T cells. Therefore, we reasoned that these mutations could be co-opted to improve T cell therapies. Here we systematically screened the effects of 71 mutations from T cell neoplasms on T cell signalling, cytokine production and in vivo persistence in tumours. We identify a gene fusion, CARD11-PIK3R3, found in a CD4+ cutaneous T cell lymphoma2, that augments CARD11-BCL10-MALT1 complex signalling and anti-tumour efficacy of therapeutic T cells in several immunotherapy-refractory models in an antigen-dependent manner. Underscoring its potential to be deployed safely, CARD11-PIK3R3-expressing cells were followed up to 418 days after T cell transfer in vivo without evidence of malignant transformation. Collectively, our results indicate that exploiting naturally occurring mutations represents a promising approach to explore the extremes of T cell biology and discover how solutions derived from evolution of malignant T cells can improve a broad range of T cell therapies.

Tissue-Resident Memory T Cells in Skin Diseases: A Systematic Review

In health, the non-recirculating nature and long-term persistence of tissue-resident memory T cells (TRMs) in tissues protects against invading pathogens. In disease, pathogenic TRMs contribute to the recurring traits of many skin diseases. We aimed to conduct a systematic literature review on the current understanding of the role of TRMs in skin diseases and identify gaps as well as future research paths. EMBASE, PubMed, SCOPUS, Web of Science, Clinicaltrials.gov and WHO Trials Registry were searched systematically for relevant studies from their inception to October 2020. Included studies were reviewed independently by two authors. This study was conducted in accordance with the PRISMA-S guidelines. This protocol was registered with the PROSPERO database (ref: CRD42020206416). We identified 96 studies meeting the inclusion criteria. TRMs have mostly been investigated in murine skin and in relation to infectious skin diseases. Pathogenic TRMs have been characterized in various skin diseases including psoriasis, vitiligo and cutaneous T-cell lymphoma. Studies are needed to discover biomarkers that may delineate TRMs poised for pathogenic activity in skin diseases and establish to which extent TRMs are contingent on the local skin microenvironment. Additionally, future studies may investigate the effects of current treatments on the persistence of pathogenic TRMs in human skin.

Highly Multiplexed Phenotyping of Immunoregulatory Proteins in the Tumor Microenvironment by CODEX Tissue Imaging

Immunotherapies are revolutionizing cancer treatment by boosting the natural ability of the immune system. In addition to antibodies against traditional checkpoint molecules or their ligands (i.e., CTLA-4, PD-1, and PD-L1), therapies targeting molecules such as ICOS, IDO-1, LAG-3, OX40, TIM-3, and VISTA are currently in clinical trials. To better inform clinical care and the design of therapeutic combination strategies, the co-expression of immunoregulatory proteins on individual immune cells within the tumor microenvironment must be robustly characterized. Highly multiplexed tissue imaging platforms, such as CO-Detection by indEXing (CODEX), are primed to meet this need by enabling >50 markers to be simultaneously analyzed in single-cells on formalin-fixed paraffin-embedded (FFPE) tissue sections. Assembly and validation of antibody panels is particularly challenging, with respect to the specificity of antigen detection and robustness of signal over background. Herein, we report the design, development, optimization, and application of a 56-marker CODEX antibody panel to eight cutaneous T cell lymphoma (CTCL) patient samples. This panel is comprised of structural, tumor, and immune cell markers, including eight immunoregulatory proteins that are approved or currently undergoing clinical trials as immunotherapy targets. Here we provide a resource to enable extensive high-dimensional, spatially resolved characterization of the tissue microenvironment across tumor types and imaging modalities. This framework provides researchers with a readily applicable blueprint to study tumor immunology, tissue architecture, and enable mechanistic insights into immunotherapeutic targets.

Aggressive CD4/CD8 Double-Negative Primary Cutaneous T-Cell Lymphoma With Dural Invasion: A Rare Presentation of Mycosis Fungoides?

ABSTRACT

Mycosis fungoides (MF) is primarily characterized by epidermotropic CD3+/CD4+/CD45RO+ memory T cells. CD4/CD8 double-negative MF is an uncommon variant with no presumed prognostic significance. Despite the variability in the clinical course and presentation of MF, most cases behave indolently. About 5% of patients, however, advance to stage IV with visceral organ involvement. Central nervous system metastasis in MF is rare with no known cases of direct central nervous system invasion by MF to date. We report an exceedingly rare locally aggressive case of CD4/CD8 double-negative MF with direct dural invasion and underline pertinent diagnostic challenges encountered in our case.

The immunopathogenesis and immunotherapy of cutaneous T cell lymphoma: Current and future approaches

In the past few decades, immunotherapy has emerged as an effective therapeutic option for patients with cutaneous T cell lymphoma (CTCL). CTCL is characterized by progressive impairment of multiple arms of the immune system. Immunotherapy targets these deficits to stimulate a more robust antitumor response, thereby both clearing the malignant T cells and repairing the immune dysfunction. By potentiating rather than suppressing the immune system, immunotherapy can result in longer treatment responses than alternatives such as chemotherapy. In recent years, advances in our understanding of the pathogenesis of CTCL have led to the development of several new agents with promising efficacy profiles. The second article in this continuing medical education series describes the current immunotherapeutic options for treatment of CTCL, with a focus on how they interact with the immune system and their treatment outcomes in case studies and clinical trials. We will discuss established CTCL immunotherapies, such as interferons, photopheresis, and retinoids; emerging therapies, such as interleukin-12 and Toll-like receptor agonists; and new approaches to targeting tumor antigens and checkpoint molecules, such as mogamulizumab, anti-programmed cell death protein 1, anti-CD47, and chimeric antigen receptor T cell therapy. We also describe the principles of multimodality immunotherapy and the use of total skin electron beam therapy in such regimens.

Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen in erythrodermic cutaneous T-cell lymphoma (CTCL) patients

Erythroderma can occur in cutaneous T-cell lymphoma (CTCL). Staphylococcus aureus (S. aureus) prevalence is increased in CTCL patients and contributes to CTCL disease flares. Our primary aim was to describe S. aureus infections, including resistance patterns and the antibiotic treatment regimens used, in erythrodermic CTCL patients. This was a retrospective chart review of erythrodermic CTCL patients who had S. aureus infection or colonization and were treated at the UT MD Anderson Cancer Center's Melanoma Skin Center between 2012 and 2016. Twenty-six erythrodermic CTCL patients had 50 documented S. aureus colonization or infection events. Patients had an improvement in body surface area (BSA) or modified Severity Weighted Assessment Tool (mSWAT) in 53% events treated for S. aureus. Seventeen of the 50 (34%) events were due to methicillin-resistant S. aureus (MRSA). One-third (33%) of MRSA events were initially treated with dicloxacillin. The MRSA isolates were sensitive to trimethoprim-sulfamethoxazole (92%) and doxycycline (88%). Patients treated in the outpatient setting (OR 0.073; 95% CI 0.008-0.627; p = 0.017) and patients with a previous history of topical anti-S. aureus decolonization treatments before S. aureus event as stand-alone (OR 0.125; 95% CI 0.018-0.887; p = 0.038) or in combination treatment with systemic antibiotics (OR 0.094; 95% CI 0.009-0.944; p = 0.045) were less likely to see improvement in BSA or mSWAT from S. aureus treatment. Treatment of S. aureus improved CTCL skin score in a high number of erythrodermic patients. The MRSA prevalence was high in erythrodermic CTCL patients. Clinicians should consider using empiric MRSA antibiotic coverage for these patients.

Staphylococcus aureus alpha-toxin inhibits CD8+ T cell-mediated killing of cancer cells in cutaneous T-cell lymphoma

Staphylococcus aureus and its toxins have been linked to disease progression and mortality in advanced stages of cutaneous T-cell lymphoma (CTCL). CD8+ T cells play a crucial role in anti-cancer responses and high CD8+ T cell numbers in tumor lesions are associated with a favorable prognosis in CTCL. Here, we show that CD8+ T cells from both healthy donors and Sézary syndrome patients are highly susceptible to cell death induced by Staphylococcal alpha-toxin, whereas malignant T cells are not. Importantly, alpha-toxin almost completely blocks cytotoxic killing of CTCL tumor cells by peptide-specific CD8+ T cells, leading to their escape from induced cell death and continued proliferation. These findings suggest that alpha-toxin may favor the persistence of malignant CTCL cells in vivo by inhibiting CD8+ T cell cytotoxicity. Thus, we propose a novel mechanism by which colonization with Staphylococcus aureus may contribute to cancer immune evasion and disease progression in CTCL.

Exposure-Response Analysis for Mogamulizumab in Adults With Cutaneous T-Cell Lymphoma

Mogamulizumab is a humanized monoclonal antibody against C-C chemokine receptor 4 approved in the United States for the treatment of patients with relapsed/refractory mycosis fungoides or Sézary syndrome, the most common forms of cutaneous T-cell lymphoma (CTCL). The exposure-response relationships for efficacy (progression-free survival [PFS] and overall response rate [ORR]) and safety (the 5 most common treatment-related adverse events by Medical Dictionary for Regulatory Activities [MedDRA] System Organ Class) for 184 patients with CTCL treated with mogamulizumab in a large, registrational clinical trial. Exposure metrics were area under the serum mogamulizumab concentration-time curve over the dose interval at steady state (AUC_ss ) and minimum serum mogamulizumab concentration after the first dose (C_min,1st ). PFS by investigator assessment, the primary efficacy objective, and PFS and ORR by independent review were not correlated with exposure metrics; however, there was a statistically significant positive relationship between a secondary objective, ORR by investigator assessment, and AUC_ss (P = .0168). The frequency of treatment-related adverse events was not related to exposure metrics (C_min,1st or AUC_ss ) for any of the MedDRA System Organ Classes examined. Of the covariates that were found to have a statistically significantly effect on the population PK model (ie, albumin, aspartate aminotransferase, body surface area, mild to moderate hepatic impairment, and sex), none was found to impact efficacy or safety, indicating that there is no need to modify dose on the basis of these parameters.

Aggressive Rare T-cell Lymphomas with Manifestation in the Skin: A Monocentric Cross-sectional Case Study

Rare T- or NK-cell lymphomas with cutaneous manifestation may display a highly aggressive clinical course and major diagnostic/therapeutic challenges. This report describes our experiences with different lymphomas of this rare category and the therapeutic options used. This retrospective, descriptive, monocentric, cross-sectional case study, identified 4 rare aggressive T-/NK-cell lymphomas with manifestation in the skin, which were diagnosed in a tertiary care centre over a period of 4 years. Two patients had an Epstein-Barr virus-associated extranodal NK/T-cell lymphoma and 2 patients had a primary cutaneous CD8+ aggressive epidermotropic cytotoxic T-cell lymphoma. Concomitant extracutaneous involvement was observed in 2 of all 4 patients. Two patients had fulminant disease progression and resistance to chemotherapy. Two patients underwent allogeneic haematopoietic stem cell transplantation, which resulted in one complete remission and one partial remission. This report emphasizes the importance of an early diagnostic work-up and a prompt aggressive therapeutic approach.

The development of primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoproliferative disorder at the site of a melanoma excision scar

Primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoproliferative disorder (PCSM-LPD) is a rare and low-grade form of cutaneous T-cell lymphoma (CTCL), representing 2% of all primary cutaneous lymphomas. Because of its rarity, the etiology or exact clinicopathology of PCSM-LPD remains unclear. We present the first case of PCSM-LPD, to our knowledge, arising at a past melanoma excision site. A 72-year-old woman with a past medical history significant for melanoma-in-situ excised 36 years ago presented to our clinic for evaluation of a single, erythematous plaque of the posterior arm within a melanoma excision scar. A biopsy was performed, revealing PCSM-LPD. Reports of the development of other T-cell lymphoproliferative disorders after prior skin trauma such as chemical burns, thermal injury, and mechanical trauma exist in the literature. Physicians should be aware of the possibility of the appearance of T-cell lymphoproliferative disorders at the site of scars or prior trauma with a time lag of months to years.

Role of Dysregulated Cytokine Signaling and Bacterial Triggers in the Pathogenesis of Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma is a heterogeneous group of lymphomas characterized by the accumulation of malignant T cells in the skin. The molecular and cellular etiology of this malignancy remains enigmatic, and what role antigenic stimulation plays in the initiation and/or progression of the disease remains to be elucidated. Deep sequencing of the tumor genome showed a highly heterogeneous landscape of genetic perturbations, and transcriptome analysis of transformed T cells further highlighted the heterogeneity of this disease. Nonetheless, using data harvested from high-throughput transcriptional profiling allowed us to develop a reliable signature of this malignancy. Focusing on a key cytokine signaling pathway previously implicated in cutaneous T-cell lymphoma pathogenesis, JAK/STAT signaling, we used conditional gene targeting to develop a fully penetrant small animal model of this disease that recapitulates many key features of mycosis fungoides, a common variant of cutaneous T-cell lymphoma. Using this mouse model, we show that T-cell receptor engagement is critical for malignant transformation of the T lymphocytes and that progression of the disease is dependent on microbiota.

Ontak-like human IL-2 fusion toxin

Ontak® is a FDA-approved diphtheria toxin-based recombinant fusion toxin for treatment of human CD25⁺ cutaneous T cell lymphoma (CTCL). However, it has been discontinued clinically due to the production issue related to the bacterial expression system with difficult purification. Recently we have developed monovalent and bivalent human IL-2 fusion toxins targeting human CD25⁺ cells using advanced unique diphtheria toxin resistant yeast Pichia Pastoris expression system. In vitro efficacy characterization using human CD25⁺ HUT102/6TG cells demonstrated that both monovalent and bivalent isoforms are potent and the bivalent isoform is approximately two logs more potent than the monovalent isoform. In this study, we further assessed the in vivo efficacy of the human IL-2 fusion toxins using human CD25⁺ HUT102/6TG tumor-bearing NSG mouse model. The data demonstrated that both monovalent and bivalent human IL-2 fusion toxins significantly prolonged the survival of the human CD25⁺ tumor-bearing NSG mice in a dose-dependent manner. Then we further assessed the residual tumor cells from the HUT102/6TG tumor-bearing NSG mice using the residual tumor cell bearing NSG mouse model. The results demonstrated that the residual tumor cells were still sensitive to the continual treatment with the human IL-2 fusion toxin. This yeast-expressed human IL-2 fusion toxin will be a promising candidate to replace the clinically discontinued Ontak®.

Innovative Treatment Concepts for Cutaneous T-Cell Lymphoma Based on Microenvironment Modulation

Cutaneous T-cell lymphomas (CTCL) are a rare and biologically heterogeneous malignant entity comprising mycosis fungoides and Sézary syndrome as the most common subtypes. The current treatment outcome is characterized by high rates of relapse, but survival is usually not significantly shortened in low-stage disease. This is different in tumor-stage disease or aggressive CTCL subtypes where survival is significantly reduced. Recent advances have been made on several levels of tumor biology: Whole genome sequencing has resulted in novel strategies of NF-κB or JAK inhibition, ongoing translational research has revealed new targets like CD30 or CCR4, and, finally, research focusing on impaired immunosurveillance has gained more importance. Based on the growing knowledge about the functional roles of the tumor microenvironment and non-malignant infiltrating cells, current research aims to develop novel CTCL treatment strategies. This review focuses on the mounting evidence for efficiently targeting tumor-infiltrating immune cells and thereby modulating the tumor microenvironment and restoring immunosurveillance.

Th17 cytokine differentiation and loss of plasticity after SOCS1 inactivation in a cutaneous T-cell lymphoma

We propose that deregulated T-helper-cell (Th) signaling underlies evolving Th17 cytokine expression seen during progression of cutaneous T-cell lymphoma (CTCL). Accordingly, we developed a lymphoma progression model comprising cell lines established at indolent (MAC-1) and aggressive (MAC-2A) CTCL stages. We discovered activating JAK3 (V722I) mutations present at indolent disease, reinforced in aggressive disease by novel compound heterozygous SOCS1 (G78R/D105N) JAK-binding domain inactivating mutations. Though isogenic, indolent and aggressive-stage cell lines had diverged phenotypically, the latter expressing multiple Th17 related cytokines, the former a narrower profile. Importantly, indolent stage cells remained poised for Th17 cytokine expression, readily inducible by treatment with IL-2 - a cytokine which mitigates Th17 differentiation in mice. In indolent stage cells JAK3 expression was boosted by IL-2 treatment. Th17 conversion of MAC-1 cells by IL-2 was blocked by pharmacological inhibition of JAK3 or STAT5, implicating IL2RG - JAK3 - STAT5 signaling in plasticity responses. Like IL-2 treatment, SOCS1 knockdown drove indolent stage cells to mimic key aggressive stage properties, notably IL17F upregulation. Co-immunoprecipitation experiments showed that SOCS1 mutations abolished JAK3 binding, revealing a key role for SOCS1 in regulating JAK3/STAT5 signaling. Collectively, our results show how JAK/STAT pathway mutations contribute to disease progression in CTCL cells by potentiating inflammatory cytokine signaling, widening the potential therapeutic target range for this intractable entity. MAC-1/2A cells also provide a candidate human Th17 laboratory model for identifying potentally actionable CTCL markers or targets and testing their druggability in vitro.

Induction of anti-tumor CD8 T cell responses by experimental ECP-induced human dendritic antigen presenting cells

Extracorporeal photochemotherapy (ECP), or photopheresis, is distinguished by the specificity of the clinically potent immunologic reactions it initiates or regulates. The selectivity of ECP-induced immunoprotection for the malignant clone in cutaneous T cell lymphoma (CTCL), and for the pathogenic clones in allograft rejection and graft-versus-host disease (GVHD), has suggested a central mechanistic role for dendritic antigen presenting cells (DC). Discovery of ECP's induction of monocyte-derived DC, via monocyte signaling by ECP-plate activated platelets, and the absolute dependency of experimental ECP on such induced DC, supports that premise. Herein, we show that ECP-induced DC are capable of stimulating CD8 T cell responses to tumor antigens with which they are loaded. They internalize an antigen-specific melanoma-associated protein then present it onto a class I major histocompatibility, which then stimulates expansion of anti-tumor CD8 T cell populations. We conclude that ECP-induced DC prominently contribute to its initiation of anti-tumor immunity and raise the possibility that the therapy may be applicable to the immunotherapeutic management of a broader spectrum of cancers.

[THE DYNAMICS OF IMMUNOLOGICAL RESULTS OF PATIENTS WITH T-CELL SKIN LYMPHOMAS AND PSORIASIS BY THE THERAPY OF ACTIVATION MECHANISMS SANOGENESIS METHODS]

The therapy T-cell skin lymphoma and psoriasis by the application of activation mechanisms sanogenesis methods, such as: original--a treatment plasmapheresis, a standard heparin infusion; used for the first time--wobenzym; solutions of acid acetic food and sodium bicarbonate; known--the basic sanitations of concomitant diseases, photopheresis caused remissions in 79.6% patients with different stages T-cell skin lymphoma (observed over an 8-year span), and in 67% of patients with psoriasis (observed over an 6-year span). Depuration reactions (phagocytosis, pinocytosis, toxin neutralization) has been activated by detoxication of treatment plasmapheresis and heparin infusions. The topical therapy with wobenzym, solutions of acid acetic food and sodium bicarbonate renewed natural immune barrier of skin. Basic therapy of concomitant diseases enhanced of patient state of health and mobilized compensatory resources. Photopheresis initiated autoimmunization processes by malignant CD4+ lymphocytes. When remission was achieved, the parameters of cellular and humoral immunity returned to normal levels, or the parameters made worse in the absence of remission.

IPH4102, a humanized KIR3DL2 antibody with potent activity against cutaneous T-cell lymphoma

Advanced cutaneous T-cell lymphoma (CTCL) remains an unmet medical need, which lacks effective targeted therapies. In this study, we report the development of IPH4102, a humanized monoclonal antibody that targets the immune receptor KIR3DL2, which is widely expressed on CTCL cells but few normal immune cells. Potent antitumor properties of IPH4102 were documented in allogeneic human CTCL cells and a mouse model of KIR3DL2(+) disease. IPH4102 antitumor activity was mediated by antibody-dependent cell cytotoxicity and phagocytosis. IPH4102 improved survival and reduced tumor growth in mice inoculated with KIR3DL2(+) tumors. Ex vivo efficacy was further evaluated in primary Sézary patient cells, sorted natural killer-based autologous assays, and direct spiking into Sézary patient peripheral blood mononuclear cells. In these settings, IPH4102 selectively and efficiently killed primary Sézary cells, including at unfavorable effector-to-target ratios characteristic of unsorted PBMC. Together, our results offer preclinical proof of concept for the clinical development of IPH4102 to treat patients with advanced CTCL.

The role of IL-22 and Th22 cells in human skin diseases

Interleukin (IL)-22 is a cytokine that is involved in the modulation of tissue responses during inflammation. It is produced by immune cell subsets such as T cells, while the expression of its receptor is restricted to cells of non-hematopoietic origin, particularly epithelial cells. In the skin, IL-22 induces keratinocyte proliferation and epidermal hyperplasia, inhibits terminal differentiation of keratinocytes, and promotes the production of antimicrobial proteins. Although IL-22 was initially thought to be produced by T helper (Th)17 cells, IL-22 production can also occur in an apparently unique subset of cells, Th22 cells, which lack the ability to produce IL-17 and interferon-γ. Of note, Th22 cells, which express the skin homing chemokine receptors CCR4 and CCR10, reside in the normal skin and are enriched in the lesional skin of inflammatory skin diseases, indicating the importance of IL-22 in skin homeostasis and pathogenesis of skin diseases. Although a critical role of IL-22 was initially highlighted in psoriasis, a growing body of evidence indicates that this cytokine also plays a role in atopic dermatitis and other inflammatory skin diseases. Moreover, emerging experimental data suggest that IL-22 also participates in the pathophysiology of malignancies of the skin. In this review, recent findings regarding the expression, regulation, and function of the IL-22 pathway in various human skin diseases will be discussed. Considering the strong association between excess activation of the IL-22/Th22 pathway and human skin diseases, targeting this pathway may provide promising new therapeutic approaches.

Association of nerve growth factor, chemokine (C-C motif) ligands and immunoglobulin E with pruritus in cutaneous T-cell lymphoma

Many patients with cutaneous T-cell lymphoma (CTCL) experience severe pruritus. This study evaluated serum levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in patients with CTCL. Although serum NGF and BDNF levels in patients with CTCL were not significantly higher than in healthy controls, serum NGF levels in patients with Sézary syndrome were higher than in those with mycosis fungoides and in healthy controls. Enhanced NGF expression by keratinocytes and increased dermal nerve fibres were detected in lesional skin of subjects with Sézary syndrome. Correlations between pruritus in CTCL and serum levels of NGF, BDNF, chemokine (C-C motif) ligand 1 (CCL1), CCL17, CCL26, CCL27, lactate dehydrogenase (LDH), IgE, and soluble interleukin-2 receptor were analysed. Serum CCL1, CCL26, LDH, and IgE levels correlated with pruritus in patients with CTCL. NGF may be associated with increased dermal nerve fibres and pruritus in Sézary syndrome, and CCL1, CCL26, and IgE may be associated with pruritus in CTCL.

Primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma: transformation from indolent to aggressive phase in association with CCR7-positive conversion

We report a case of primary cutaneous aggressive epidermotropic CD8+ T-cell lymphoma that transformed from the indolent phase to the aggressive phase. In the aggressive phase, the patient developed numerous subcutaneous lesions on the trunk, limbs, and face. The involvement of muscle, right testis, and pharynx were also found. We immunohistochemically analyzed the expression of chemokine receptors, before and after the transformation of aggressive epidermotropic CD8+ T-cell lymphoma. The transformation was accompanied by positive conversion of CCR7. CCR7 is crucial in lymphatic cell migration and chemotaxis to lymph nodes. Therefore, its expression is likely associated with the disseminated behavior of T-cell lymphoma.

Primary cutaneous aggressive epidermotropic CD8+ T cell lymphoma with a chronic and indolent course. Is this different from peripheral T cell lymphoma?

Cutaneous T cell lymphomas most commonly have a CD4+ memory T cell phenotype and exhibit a relatively indolent course, but may in rare cases present with a CD8+ cytotoxic phenotype with a strikingly more aggressive clinical behavior. Primary cutaneous aggressive epidermotropic CD8+ T cell lymphoma is an extremely rare entity with distinct clinicopatological features. The clinical features and prognosis of the recently-described CD8+ peripheral lymphoma are very different from cytotoxic CD8+ epidermotropic lymphoma, but the histological and phenotypic characteristics are very similar. We report a new case of CD8+ epidermotropic lymphoma with a chronic course and suggest the possibility of an overlap between these two types of lymphoma.

Cutaneous T-cell lymphoma: 2011 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell lymphoproliferative disorders involving the skin, the majority of which may be classified as Mycosis fungoides (MF) or Sézary syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

Tumor, node, metastasis, and blood (TNMB) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multidisciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral, or blood involvement are generally approached with biologic-response modifiers, denileukin diftitox, and histone deacetylase inhibitors before escalating therapy to include systemic, single-agent chemotherapy. Multiagent chemotherapy may be used for those patients with extensive visceral involvement requiring rapid disease control. In highly-selected patients with disease refractory to standard treatments, allogeneic stem-cell transplantation may be considered.

Molecular markers associated with clinical response to bexarotene therapy in cutaneous T-cell lymphoma

Bexarotene (Targretin(®)), was registered for the treatment of cutaneous T-cell lymphoma (CTCL) in 2002, and has been reported to induce a 45% overall response. Responses are mostly partial or generate a stable, skin-restricted disease. This study explored the usefulness of a novel cancer-associated gene, NAV3 and corresponding chromosome 12 copy numbers as possible biomarkers to monitor the therapeutic response to bexarotene in 21 Finnish patients with CTCL. Six patients (29%) reached complete remission (CR) and 3 of these remained in CR for more than 24 months, 12 (57%) reached a partial response (PR, with one stable disease) and 3 were non-responders. Low-level NAV3 deletions were detected using a fluorescence in-situ hybridization (FISH) assay in the lesions of 5 patients, 4 of whom were non-responders or progressed after short PR. This occurrence of NAV3 deletions was statistically significant compared with non-progressors (p = 0.011, Fisher's exact test). Chromosome 12 tetraploidy was found in the lesions of two of the 3 patients with CR who remained in remission. While such tetraploidy is a feature of proliferating normal T cells, this observation may reflect a favourable anti-tumour immune response among the skin-infiltrating lymphocytes.

Activation of coagulation in bullous pemphigoid and other eosinophil-related inflammatory skin diseases

Bullous pemphigoid (BP) is a skin disease caused by autoantibodies to hemidesmosomal proteins BP180 and BP230, with eosinophils participating in blister formation. Tissue factor (TF), the initiator of coagulation, is embodied within the eosinophil granules and exposed upon activation. We evaluated the coagulation activation in patients with BP (63), chronic urticaria (CU; 20), atopic dermatitis (AD; 14), cutaneous drug reactions (CDRs; six), psoriasis (20), dermatitis herpetiformis (DH; four) and primary cutaneous T cell lymphoma (CTCL; five), and in 40 healthy controls. Prothrombin fragment F1+2 and d-dimer (coagulation markers) were measured by enzyme-linked immunosorbent assay (ELISA) in all plasma samples and BP blister fluid. Skin TF expression was evaluated immunohistochemically in the patients and 20 controls. F1+2 and d-dimer levels were higher in BP plasma than in control plasma (P = 0·0001 for both), and dramatically high in blister fluid; both correlated positively with disease severity, esinophil counts and anti-BP180 antibodies (P = 0·006-0·0001). Plasma F1+2 and d-dimer levels were higher in the CU, AD and CDR patients than in controls (P = 0·0001 for all), but normal in the psoriasis, DH and CTCL patients. Skin TF was expressed in the BP (P = 0·0001), CU (P = 0·0001), AD (P = 0·001) and CDR patients (P = 0·01), but not in the psoriasis, DH or CTCL patients. Co-localization confocal microscopy studies confirmed eosinophils as the source of TF in 10 BP patients. The coagulation cascade is activated in BP and other eosinophil-mediated skin disorders, but not in non-eosinophil driven conditions. This hypercoagulability may contribute to inflammation, tissue damage and, possibly, thrombotic risk.

Dendritic cells and cutaneous T-cell lymphomas

Dendritic cells (DCs) are potent antigen-presenting cells that help orchestrate the innate and adaptive immune systems to induce tolerance and immunity. They are diversified in their phenotypes, stages of maturation, degrees of activation, and functions. Several subtypes of DCs exist among human lymphoid tissues, non-lymphoid tissues, and in peripheral blood. In the skin, three types of DCs are described: Langerhans cells (LCs), dermal dendritic cells (DDCs), and plasmacytoid dendritic cells (pDCs). In the peripheral blood, myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells are well described. Dysfunctional DCs are found in many autoimmune disorders, allergies, and cancers. In this paper, we focus on DCs as related to cutaneous T cell lymphomas (CTCLs). Abnormal DC number and defective DC function are found in the blood of patients with advanced stage Sézary syndrome (SS), a leukemic variant of CTCLs. Extracorporeal photopheresis (ECP), an effective therapy for erythrodermic CTCLs, is thought to work by inducing apoptosis of tumor cells and monocytes-derived DCs. DC vaccination has been carried out successfully in some patients with CTCLs when combined with immune modifiers like toll like receptor agonists, which may enhance the function of DCs. However, DCs may perform a dual role in the pathogenesis of CTCLs. Immature DCs (langerhans cells) could promote the survival of malignant T cells. Further understanding of DCs and their role in CTCLs can help us to uncover the pathogenesis of this disease and to further explore the therapeutic uses of DCs.

[A spontaneously resolving T-cell lymphoma]

BACKGROUND

Primary cutaneous CD30+ anaplastic large-cell lymphoma is a rare form of non-Hodgkin's lymphoma, which is restricted to the skin.

CASE DESCRIPTION

A 50-year-old man presented with an asymptomatic tumorous area in the groin that had appeared within the previous week, and a longer history of a transient red, flaking area in the popliteal space. Histopathological findings were consistent with CD30+ anaplastic large-cell lymphoma. Staging demonstrated no extracutanous spread. The skin lesions disappeared without treatment within 3 months.

CONCLUSION

Primary cutaneous CD30+ anaplastic large-cell lymphoma is a rare condition. It has a histopathological picture of a diffuse proliferation of large atypical anaplastic cells, suggesting an unfavourable disease course. However, this condition is characterised by a indolent course and favourable prognosis since spontaneous complete regression can occur.

Thalidomide and analogues: potential for immunomodulation of inflammatory and neoplastic dermatologic disorders

Thalidomide and analogues are a class of immunomodulatory drugs or IMiDS. Thalidomide was initially approved by the U.S. Food and Drug Administation for treatment of erythema nodosum in leprosy and is now approved for multiple myeloma as well. A second generation IMiD, lenalidomide, is also approved for multiple myeloma and refractory myelodysplastic syndrome. Discovery of this class of drugs has been serendipitous and empirical, as the drug targets have been unknown. In this review, the authors integrate recent identification of drug targets of IMiDS, which include the inducible form of nitric oxide synthase (iNOS), Rho GTPase and caspase-1, with the developments in the understanding of the molecular biology of human inflammatory, infectious and neoplastic skin disorders. Because thalidomide reemerged through leprosy, the original disease classified by the T cell, the authors have also emphasized advances in the understanding of T-cell subsets in human skin disorders.

CD4 (+)CD25 (+)Foxp3 (+) regulatory T cells and hematologic malignancies

Regulatory T cells (Tregs) are an immunosuppressive T cell subset that functions to prevent autoimmunity and to regulate physiologic immune reactions. Tregs are also present in the tumor microenvironment and appear to play an important role in the pathophysiology of malignant processes. Available data suggests that this role is context-dependent, as a higher density of tumor infiltrating Tregs at diagnosis may be associated with either a positive or a negative clinical outcome. Negative prognostic associations are found primarily in solid tumors such as ovarian carcinoma, while positive associations have been reported in various lymphomas, most prominently in those of germinal center (GC) B cell derivation. Most of these observations are correlative, however, as mechanistic studies have lagged behind descriptive observations because of a lack of informative animal models. Nonetheless, the available data are intriguing and provide compelling support for the hypothesis that Tregs are pathobiologically relevant. This review focuses on studies of the role of CD4 (+)CD25 (+)FOXP3 (+) Tregs in hematopoietic malignancies and clonal myeloid neoplasms.