Treatment of cutaneous T-cell lymphoma by extracorporeal photochemotherapy. Preliminary results

Randomized phase II trial of extracorporeal phototherapy and steroids vs. steroids alone for newly diagnosed acute GVHD

Steroids remain the initial therapy for acute graft-vs.-host disease (AGVHD). Strategies to improve response and minimize steroid exposure are needed. We report results of a randomized, adaptive, Bayesian-designed, phase II trial of prednisone with or without extracorporeal photopheresis (ECP) as an initial therapy for patients with newly diagnosed AGVHD. The primary endpoint was success at day 56 defined as: alive, in remission, achieving AGVHD response without additional therapy, and on <1 mg/kg at day 28 and <0.5 mg/kg on day 56 of steroids. Eighty-one patients were randomized to the ECP arm (n = 51) or steroids alone (n = 30). Median age was 54 years (range: 17-75); 90% had grade II AGVHD and 10% had grades III and IV AGVHD, with skin (85%), upper (22%)/lower (22%) gastrointestinal, and liver (10%) involvement. The ECP arm had a higher probability of success (0.815) and exceeded the predefined threshold for determining the investigational arm promising. ECP was potentially more beneficial than steroids-alone in skin-only AGVHD (response rate: 72% vs. 57%, respectively) than for visceral-organ AGVHD (47% vs. 43%, respectively). The addition of ECP to steroids may result in higher GVHD response as initial therapy for AGVHD, especially for patients with skin-only involvement.

[UV phototherapy : UV phototherapy and photodiagnostics-a practical overview]

UV phototherapy is an essential and efficient therapeutic option in the treatment of dermatological diseases. It is an integral part of multiple guidelines and maintains its high clinical significance despite the development of new therapeutic options for systemic treatment. Due to the difficult revenue situation, the market for ready-to-use products of psoralen and UV therapy devices is constantly changing.

Management of primary cutaneous lymphomas during the COVID-19 pandemic

Primary cutaneous lymphomas are defined as a heterogenic group of T- and B-cell non-Hodgkin lymphomas that present initially in the skin. Patients with primary cutaneous lymphomas are at a higher risk for developing complications in case of infection with the novel coronavirus severe acute respiratory syndrome coronavirus 2. The coronavirus disease 2019 (COVID-19) pandemic has affected the established diagnostic approach, staging, and therapeutic guidelines in patients with primary cutaneous lymphomas. In the light of the current global health crisis, management of primary cutaneous lymphomas needs to be adjusted. The key to achieving this is to balance the optimal control of the lymphoma, with a minimal increase of the personal risk for COVID-19 exposure and complications.

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.

A deep dive into UV-based phototherapy: Mechanisms of action and emerging molecular targets in inflammation and cancer

UV-based phototherapy (including psoralen plus UVA (PUVA), UVB and UVA1) has a long, successful history in the management of numerous cutaneous disorders. Photoresponsive diseases are etiologically diverse, but most involve disturbances in local (and occasionally systemic) inflammatory cells and/or abnormalities in keratinocytes that trigger inflammation. UV-based phototherapy works by regulating the inflammatory component and inducing apoptosis of pathogenic cells. This results in a fascinating and complex network of simultaneous events-immediate transcriptional changes in keratinocytes, immune cells, and pigment cells; the emergence of apoptotic bodies; and the trafficking of antigen-presenting cells in skin-that quickly transform the microenvironment of UV-exposed skin. Molecular elements in this system of UV recognition and response include chromophores, metabolic byproducts, innate immune receptors, neurotransmitters and mediators such as chemokines and cytokines, antimicrobial peptides, and platelet activating factor (PAF) and PAF-like molecules that simultaneously shape the immunomodulatory effects of UV and their interplay with the microbiota of the skin and beyond. Phototherapy's key effects-proapoptotic, immunomodulatory, antipruritic, antifibrotic, propigmentary, and pro-prebiotic-promote clinical improvement in various skin diseases such as psoriasis, atopic dermatitis (AD), graft-versus-host disease (GvHD), vitiligo, scleroderma, and cutaneous T-cell lymphoma (CTCL) as well as prevention of polymorphic light eruption (PLE). As understanding of phototherapy improves, new therapies (UV- and non-UV-based) are being developed that will modify regulatory T-cells (Treg), interact with (resident) memory T-cells and /or utilize agonists and antagonists as well as antibodies targeting soluble molecules such as cytokines and chemokines, transcription factors, and a variety of membrane-associated receptors.

A simplified extracorporeal photopheresis procedure based on single high-dose ultraviolet A light irradiation shows similar in vitro efficacy

BACKGROUND

Extracorporeal photopheresis (ECP) is one of the most widely used and effective cell-based therapies for the treatment of T-cell-mediated diseases. The patients' white blood cells (WBCs) are collected by apheresis and exposed to the photosensitizer 8-methoxypsoralen (8-MOP) and ultraviolet A (UVA) light before retransfusion. The UVA/8-MOP combination has been in use in ECP for more than 4 decades; however, whether ECP can be simplified by UVA light irradiation only has never been analyzed.

STUDY DESIGN AND METHODS

Peripheral blood mononuclear cells were treated with classical ECP or different UVA light doses only (UVA^only ). Treatment efficacy was investigated by apoptosis induction in WBC subsets, inhibition of T-cell proliferation, and the ability of monocytes to induce allogeneic T-cell expansion and to respond to lipopolysaccharide and interferon-γ stimulation in vitro.

RESULTS

High-dose UVA^only treatment (5 J/cm² ) was as efficient as ECP to induce apoptosis within 48 hours. UVA^only treatment modulated the composition of the surviving cells by improving monocyte survival and promoting CD8⁺ T-cell apoptosis. Both ECP and UVA^only treatment inhibited anti-CD3/anti-CD28 triggered T-cell proliferation. Interestingly, whereas ECP-treated monocytes exhibited a markedly reduced capacity to respond to stimulation and to induce allogeneic T-cell proliferation, UVA^only treatment preserved monocyte functionality to some degree.

CONCLUSIONS

High-dose UVA^only and standard ECP showed comparable efficacy in inducing apoptosis and inhibiting direct T-cell proliferation. Hence, UVA^only treatment can be a simplified alternative to ECP therapy. Furthermore, increased monocyte survival with partially preserved functionality after UVA^only treatment may provide a novel method for immunoregulation.

Photodynamic therapy of tumour cells mediated by the natural anthraquinone parietin and blue light

Photodynamic therapy (PDT) is a treatment for superficial tumours involving the administration of a photosensitiser followed by irradiation. The potential of the natural anthraquinone parietin (PTN) in PDT is still relatively unexploited. In the present work, PTN isolated from the lichen Teoloschistes nodulifer (Nyl.) Hillman (Telochistaceae) was evaluated as a potential photosensitiser on tumour cells employing UVA-Vis and blue light. Blue light of 2 J/cm² induced 50% death of K562 leukaemic cells treated 1 h with 30 μM PTN (Protocol a). Higher light doses (8 J/cm²) were needed to achieve the same percentage of cell death employing lower PTN concentrations (3 μM) and higher exposure times (24 h) (Protocol b). Cell cycle analysis after both protocols of PTN-PDT revealed a high percentage of sub-G1 cells. PTN was found to be taken up by K562 cells mainly by passive diffusion. Other tumour cells such as ovary cancer IGROV-1 and LM2 mammary carcinoma, as well as the normal keratinocytes HaCaT, were also photosensitised with PTN-PDT. We conclude that PTN is a promising photosensitiser for PDT of superficial malignancies and purging of leukaemic cells, when illuminated with blue light. Thus, this light wavelength is proposed to replace the Vis-UVA lamps generally employed for the photosensitisation of anthraquinones.

CD11c+ dendritic cells mediate antigen-specific suppression in extracorporeal photopheresis

Extracorporeal photopheresis (ECP) represents one of the most widespread and effective cell therapies for graft‐versus‐host disease and other T cell‐mediated disorders. However, the key factors affecting the therapeutic efficacy of ECP remain unclear. We hypothesized that therapeutic effects are mediated by ECP‐treated antigen‐presenting dendritic cells (DC). To test this hypothesis, we used the experimental model of contact hypersensitivity (CHS). The ECP’s therapeutic activity improved when the total cell dose of the ECP‐treated cells was increased. We used different haptens during sensitization to demonstrate that the anti‐inflammatory activity of ECP is antigen‐specific. This confirmed the hypothesis that professional antigen‐presenting cells are involved in the mode of action. Also, the ECP’s therapeutic activity was abrogated by the depletion of CD11c⁺ DC, which represents fewer than 1% of all the ECP‐exposed cells. Finally, we confirm the critical importance of CD11c⁺ DC for ECP activity by showing that only a few purified CD11c⁺ DC are sufficient to mediate its therapeutic effect. The finding that ECP‐treated, physiological antigen‐presenting DC alone mediate antigen‐specific modulation of a pathological immune response may result in better‐targeted interventions when treating patients.

Inline and offline extracorporeal photopheresis: Device performance, cell yields and clinical response

BACKGROUND

Extracorporeal photopheresis (ECP) is an effective treatment for graft-vs-host-disease (GvHD). Photopheresis can be performed in offline or inline method. The first uses a conventional cell separator for collection of mononuclear-cells that are photoactivated by a separate device and manually reinfused; the second one involves a dedicated device performing the entire procedure (collection, photoactivation and reinfusion).

STUDY DESIGN AND METHODS

The objective was to compare the two methods and cell product features to highlight key process, devices performance, and to evaluate ECP clinical response. Patients developing steroid-resistant GvHD underwent ECP as second-line treatment using either inline (Therakos CellEx) or offline system (Terumo BCT Spectra or Optia and UVA PIT system). Data about patients' features, pre-apheresis blood-count, cell product characteristics and clinical response were collected for analysis.

RESULTS

We evaluated 494 procedures performed on 28 patients from April 2018 to March 2019. The offline procedure allows to achieve greater cell yield, it is characterized by larger processed blood volume, longer runtime, and higher ACD consumption. The inline procedure shows shorter runtime, high mononuclear-cells percentage and low percentage of granulocytes in cell product. We observed a significant difference in cell yields between inline and offline system; furthermore we did not find a significant relationship between cell dose and clinical response.

CONCLUSION

Inline ECP is fast, highly automated and productive, making it particularly suitable for ECP treatments. Offline ECP collects high cell yields implying longer procedure and greater operator intervention. Our study did not find a significant relationship between cell dose and GVHD response.

Use of Ultraviolet Blood Irradiation Against Viral Infections

Ultraviolet blood irradiation (UBI) was used with success in the 1930s and 1940s for a variety of diseases. Despite the success, the lack of understanding of the detailed mechanisms of actions, and the achievements of antibiotics, phased off the use of UBI from the 1950s. The emergence of novel viral infections, from HIV/AIDS to Ebola, from SARS and MERS, and SARS-CoV-2, bring back the attention to this therapeutical opportunity. UBI has a complex virucidal activity, mostly acting on the immune system response. It has effects on lymphocytes (T-cells and B-cells), macrophages, monocytes, dendritic cells, low-density lipoprotein (LDL), and lipids. The Knott technique was applied for bacterial infections such as tuberculosis to viral infections such as hepatitis or influenza. The more complex extracorporeal photopheresis (ECP) is also being applied to hematological cancers such as T-cell lymphomas. Further studies of UBI may help to create a useful device that may find applications for novel viruses that are resistant to known antivirals or vaccines, or also bacteria that are resistant to known antibiotics.

Outcomes Following Extracorporeal Photopheresis for Chronic Lung Allograft Dysfunction Following Lung Transplantation: A Single-Center Experience

INTRODUCTION

Survival following lung transplantation (LTx) is limited by the development of chronic lung allograft dysfunction (CLAD), for which there are few effective therapies and no standardized management. Several small studies have demonstrated the effectiveness of extracorporeal photopheresis (ECP) as a therapeutic option for CLAD.

METHODS

A retrospective descriptive audit of 12 LTx recipients who received rescue ECP for CLAD over 5 years (2013-2018) at the Alfred Hospital, Melbourne, Australia, was completed. Nonresponders to ECP were defined as patients who experienced a 20% decrease in forced expiratory volume (FEV₁) within 6 weeks of commencing therapy.

RESULTS

Mean time since LTx was 849 days and mean time since diagnosis of CLAD was 131 days. Fifty-eight percent of patients were male (n = 7) and 67% responded to ECP therapy (n = 8). Among responders, the mean (95% confidence interval) decline in FEV₁ pre-ECP was 9.0 mL/day (5-12 mL/day), compared to 1.4 mL/day (0-4 mL/day) post-ECP (P = .01). Among nonresponders, mean (95% confidence interval) decline in FEV₁ was 7.2 mL/day (4-10 mL/day) pre-ECP and 5.0 mL/day (3-7 mL/day) post ECP (P = .2). Nonresponders were more likely to be female (P = .01) and neutropenic (P = .005). Patients with prior exposure to anti-thymocyte globulin had a lowered response to ECP.

CONCLUSION

Rescue ECP arrested the decline of lung function in 67% of patients with CLAD. Sex, pre-ECP neutrophil count, and exposure to anti-thymocyte globulin may help determine response to ECP. Future clinical trials are needed to confirm this effect, help predict response to therapy, and ultimately guide the placement of ECP in the treatment algorithm for CLAD.

European dermatology forum - updated guidelines on the use of extracorporeal photopheresis 2020 - part 1

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multi‐disciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐versus‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines are divided in two parts: PART I covers cutaneous T‐cell lymphoma, chronic graft‐versus‐host disease and acute graft‐versus‐host disease while PART II will cover scleroderma, solid organ transplantation, Crohn's disease, use of ECP in paediatrics practice, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

European dermatology forum: Updated guidelines on the use of extracorporeal photopheresis 2020 - Part 2

Background

Following the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T‐cell lymphoma published in 1983, this technology has received continued use and further recognition for additional earlier as well as refractory forms. After the publication of the first guidelines for this technology in the JEADV in 2014, this technology has maintained additional promise in the treatment of other severe and refractory conditions in a multidisciplinary setting. It has confirmed recognition in well‐known documented conditions such as graft‐vs.‐host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection including lung, heart and liver and to a lesser extent inflammatory bowel disease.

Materials and methods

In order to further provide recognized expert practical guidelines for the use of this technology for all indications, the European Dermatology Forum (EDF) again proceeded to address these questions in the hands of the recognized experts within and outside the field of dermatology. This was done using the recognized and approved guidelines of EDF for this task. All authors had the opportunity to review each contribution as it was added.

Results and conclusion

These updated 2020 guidelines provide at present the most comprehensive available expert recommendations for the use of extracorporeal photopheresis based on the available published literature and expert consensus opinion. The guidelines were divided into two parts: PART I covers Cutaneous T‐cell lymphoma, chronic graft‐vs.‐host disease and acute graft‐vs.‐host disease, while PART II will cover scleroderma, solid organ transplantation, Crohn’s disease, use of ECP in paediatric patients, atopic dermatitis, type 1 diabetes, pemphigus, epidermolysis bullosa acquisita and erosive oral lichen planus.

How do we treat cutaneous T-cell lymphoma?

Cutaneous T-cell lymphomas are a heterogeneous group of non-Hodgkin lymphomas which are based on the malignant proliferation of skin-related T lymphocytes. The clinical appearance, as well as the course and the associated therapeutic approach, are sometimes very different between the different subtypes. Since allogeneic stem cell transplantation is currently the only curative option, and the morbidity and mortality are not insignificant, a therapy concept should be developed that considers its often rather indolent but chronic course. This concept should enable a good disease control with as few side effects as possible and preserve or improve the quality of life. In the early stages of the disease, skin-oriented therapies are generally used first before systemic and increasingly aggressive therapeutic agents are used as the disease progresses. Considering the current guidelines, literature and subjective experience, we summarize in this review how we treat cutaneous T-cell lymphomas.

A survey of extracorporeal photopheresis treatment in pediatric patients in the United Kingdom

Extracorporeal photopheresis (ECP) is a second‐line therapy in acute and chronic GVHD and solid organ transplant rejection. We report ECP use in 98 pediatric patients in seven UK centers from 2010 to 2017, the majority treated for aGVHD (73.5%). ECP was safe and well tolerated including in low body weight patients. Most patients were on multiple immunosuppressive therapies prior to ECP; 45.9% were able to reduce or stop immunosuppression with treatment. Complete or partial response was reported in almost 60%. This study supports the need to include ECP treatment data to national transplant databases to provide accurate information regarding service provision, patient outcomes, and safety.

Psoralen Derivatives with Enhanced Potency

Psoralen is a furocoumarin natural product that intercalates within DNA and forms covalent adducts when activated by ultraviolet radiation. It is well known that this property contributes to psoralen's clinical efficacy in several disease contexts, which include vitiligo, psoriasis, graft-versus-host disease and cutaneous T-cell lymphoma. Given the therapeutic relevance of psoralen and its derivatives, we attempted to synthesize psoralens with even greater potency. In this study, we report a library of 73 novel psoralens, the largest collection of its kind. When screened for the ability to reduce cell proliferation, we identified two derivatives even more cytotoxic than 4'-aminomethyl-4,5',8-trimethylpsoralen (AMT), one of the most potent psoralens identified to date. Using MALDI-TOF MS, we studied the DNA adduct formation for a subset of novel psoralens and found that in most cases enhanced DNA binding correlated well with cytotoxicity. Generally, our most potent derivatives contain positively charged substituents, which we believe increase DNA affinity and enhance psoralen intercalation. Thus, we provide a rational approach to guide efforts toward further optimizing psoralens to fully capitalize on this drug class' therapeutic potential. Finally, the structure-activity insights we have gained shed light on several opportunities to study currently underappreciated aspects of psoralen's mechanism.

Extracorporeal Photopheresis: A Case of Immunotherapy Ahead of Its Time

Extracorporeal photopheresis (ECP) is a cell-based immunotherapy that involves the reinfusion of autologous leukocytes after exposure to psoralen and UVA. The treatment has been used for over 30 years, at first on patients with cutaneous T-cell lymphoma (CTCL) and later for the management of patients with graft-versus-host disease (GvHD), sclerosing disorders, atopic dermatitis, and other diseases that may share the common driving factor of a pathogenic T-cell clone or clones in blood circulation. Patients with clinical improvement mount an antigen-specific immune response that may have tolerance traits in the case of GvHD or anticlonal cytotoxic characteristics in the case of CTCL. The exact mechanisms that dictate one response or the other are not fully understood, but the evidence accumulated so far indicates that multiple events occur simultaneously and consequentially contribute to the end result. These include contact of cells with the outside (plastics and tubing of the ECP apparatus), exposure to psoralen and UVA that activates platelets, monocytes, and other myeloid cells, the release of damage-associated molecular patterns, differentiation of monocytes into dendritic cells, and generation and successive presentation of numerous antigens after the phagocytosis of apoptotic cells. Once reintroduced, the ECP product increases the frequency and activity of regulatory T cells (Tregs), shifts the systemic cytokine balance, and promotes extravasation of immune cells that together shape the effects of this treatment. In this review, we summarize the seminal work and most recent literature of the therapeutic mechanisms and reflect on future avenues of improvements and applications of ECP.

Extracorporeal Photopheresis in Graft-versus-Host Disease

Background and Summary

Extracorporeal photopheresis (ECP) is a leukapheresis-based procedure used in the therapy of acute and chronic graft-versus-host disease (aGvHD, cGvHD) and other diseases. Based on the substantial efficacy and the excellent safety profile in the absence of immunosuppression ECP has established itself as a major treatment form for steroid-refractory GvHD. Here we review the current literature on ECP as a treatment option for patients with aGvHD as well as cGvHD.

Key Messages

ECP is a well-established second-line therapy for cGvHD. Its role in the treatment of aGvHD is less clear but also points towards an effective second-line therapy option. In the future ECP could play a role in the prevention of GvHD. More experimental and randomized controlled trials are needed to define the best patient selection criteria, settings, and therapy regimens for GvHD.

CD209+ monocyte-derived myeloid dendritic cells were increased in patients with leukemic cutaneous T-cell lymphoma undergoing extracorporeal photopheresis via the CELLEXTM system

BACKGROUND/PURPOSE

We previously reported that myeloid dendritic cells (mDC) were increased in patients with leukemic cutaneous T-cell lymphoma (L-CTCL) following extracorporeal photopheresis (ECP) using the Therakos UVAR XTS^™ system. We now assessed monocyte-derived mDCs (Mo-DCs) in L-CTCL patients treated with the CELLEX^TM photopheresis system. CD209, a transmembrane receptor, was used to define Mo-DCs.

METHODS

Peripheral blood samples from baseline pre-ECP and at Day 2, 1 month, 3 months, and 6 months post-ECP were analyzed by flow cytometry for Lin^- HLA-DR⁺ CD123⁺ plasmacytoid dendritic cells (pDCs), Lin^- HLA-DR⁺ CD11c⁺ mDCs, and CD209⁺ mDCs. The expression of CD209 mRNA was assessed by real-time PCR.

RESULTS

At baseline, 7 of 19 patients had lower than normal mDCs, and all patients had lower than normal CD209⁺ mDCs in peripheral blood mononuclear cells (0.005% in patients, n = 19, vs 0.50% in healthy donors, n = 7, P < .0001). The CD209⁺ mDC numbers only accounted for 3.28% out of total mDCs in patients compared with 66.51% in healthy donors. After treatment, the CD209⁺ mDC numbers showed increasing trends in patients. The average absolute numbers of CD209⁺ mDCs went up by 4.8-fold at 3 months (n = 10, P = .103) and by 6.4-fold at 6 months (n = 9, P = .100). CD209 mRNA expression went up in two patients responsive to therapy, parallel to CD209⁺ mDC numbers. L-CTCL patients achieved 70% overall clinical response rate (7/10) following ECP therapy with the CELLEX^TM system.

CONCLUSIONS

Our results suggest that the CELLEX^TM photopheresis system is effective for treating L-CTCL patients like the UVAR XTS^™ system, and in vivo-generated Mo-DCs increase following ECP.

Extracorporeal Photochemotherapy: Mechanistic Insights Driving Recent Advances and Future Directions

Dendritic cells (DCs) are professional antigen-presenting cells, necessary for the initiation and maintenance of antigen-specific immunity and tolerance. Decades of research have been driven by hopes to harness the immunological capabilities of DCs and achieve physiological partnership with the immune system for therapeutic ends. Potential applications for DC-based immunotherapy include treatments for cancer, autoimmune disorders, and infectious diseases. However, DCs have poor availability in peripheral and lymphoid tissues and have poor survivability in culture, leading to the development of multiple strategies to generate and manipulate large numbers of DCs ex vivo. Among these is Extracorporeal Photopheresis (ECP), a widely used cancer immunotherapy. Recent advancements have uncovered that stimulation of monocyte-to-DC maturation via physiologic inflammatory signaling lies at the mechanistic core of ECP. Here, we describe the landscape of DC-based immunotherapy, the historical context of ECP, the current mechanistic understanding of ex vivo monocyte-to-DC maturation in ECP, and the implications of this understanding on making scientifically driven improvements to modern ECP protocols and devices.

CD8+ T cells mediate ultraviolet A-induced immunomodulation in a model of extracorporeal photochemotherapy

Extracorporeal photochemotherapy (ECP) that takes advantage of the immunomodulatory effects of UV light has been extensively used for many years for the treatment of several T cell-mediated diseases, including graft-versus-host disease (GvHD) and systemic scleroderma. Immune mechanisms that lead to the establishment of T cell tolerance in ECP-treated patients remain poorly known. In this study, we have tested the effect of UV/psoralen-treated BM-derived dendritic cells, referred to as ECP-BMDCs on the outcome of an antigen-specific T cell-mediated reaction, that is, contact hypersensitivity (CHS), which is mediated by CD8⁺ effector T cells (CD8⁺ T_eff ). The intravenous (i.v.) injection of antigen-pulsed ECP-BMDCs in recipient C57BL/6 mice induced specific CD8⁺ T cells endowed with immunomodulatory properties (referred to as CD8⁺ T_ECP ), which prevented the priming of CD8⁺ T_eff and the development of CHS, independently of conventional CD4⁺ regulatory T cells. CD8⁺ T_ECP mediated tolerance by inhibiting the migration and functions of skin DC and subsequently the priming of CD8⁺ T_eff . CD8⁺ T_ECP displayed none of the phenotypes of the usual CD8⁺ T regulatory cells described so far. Our results reveal an underestimated participation of CD8⁺ T cells to ECP-induced immunomodulation that could explain the therapeutic effects of ECP in T cell-mediated diseases.

Selective Killing of Activated T Cells by 5-Aminolevulinic Acid Mediated Photodynamic Effect: Potential Improvement of Extracorporeal Photopheresis

Extracorporeal photopheresis (ECP), a modality that exposes isolated leukocytes to the photosensitizer 8-methoxypsoralen (8-MOP) and ultraviolet-A (UV-A) light, is used to treat conditions such as cutaneous T-cell lymphoma and graft-versus-host disease. However, the current procedure of ECP has limited selectivity and efficiency; and produces only partial response in the majority of treated patients. Additionally, the treatment is expensive and time-consuming, so the improvement for this modality is needed. In this study, we used the concept of photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA), a precursor of an endogenously synthesized photosensitizer protoporphyrin IX (PpIX) in combination with blue light to explore the possibility of targeting activated human blood T cells ex vivo. With various T-cell activation protocols, a high ALA-induced PpIX production took place in activated CD3⁺, CD4⁺CD25⁺, and CD8⁺ T cell populations with their subsequent killing after blue light exposure. By contrast, resting T cells were much less damaged by the treatment. The selective and effective killing effect on the activated cells was also seen after co-cultivating activated and resting T cells. Under our clinically relevant experimental conditions, ALA-PDT killed activated T cells more selectively and efficiently than 8-MOP/UV-A. Monocyte-derived dendritic cells (DCs) were not affected by the treatment. Incubation of ALA-PDT damaged T cells with autologous DCs induced a downregulation of the co-stimulatory molecules CD80/CD86 and also upregulation of interleukin 10 (IL-10) and indoleamine 2,3-dioxygenase expression, two immunosuppressive factors that may account for the generation of tolerogenic DCs. Overall, the data support the potential use of ALA-PDT strategy for improving ECP by selective and effective killing of activated T cells and induction of immune tolerance.

Furanocoumarins in anticancer therapy - For and against

Furanocoumarins are a class of natural compounds produced by several plants, including those consumed by humans. They have been used medicinally in eastern countries for ages. Given the growing body of evidence about their anticancer potential and observations that naturally occurring compounds potentiate the antitumor activity of chemotherapeutics, more attention is paid to elucidation of the nature of furanocoumarins and the possibility of using thereof in practice. The general mechanism by which furanocoumarins eliminate cancer cells is based on cell cycle blockage and initiation of programmed death like apoptosis or autophagy. The precise molecular mechanism of such an action depends on the chemical structure of furanocoumarins, which is based on the furan ring attached to the coumarin backbone in a linear or angular form as well as the type, location, and number of the substituents attached. The review summarizes the current evidence of the antitumor properties of linear and angular furanocoumarins with special emphasis on the molecular mechanism of elimination of cancer cells via apoptosis and autophagy. Negative aspects of the use of coumarins in anticancer therapy will be also discussed especially in the context of their phototoxicity and potential cancerogenic effect.

Extracorporeal Photopheresis (ECP) and the Potential of Novel Biomarkers in Optimizing Management of Acute and Chronic Graft vs. Host Disease (GvHD)

As the use of hematopoietic stem cell transplantation (HSCT) has become a more widespread and effective treatment for hematological malignant and non-malignant conditions, the need to minimize the harmful effects of graft- vs.-host disease (GvHD) has become more important in achieving good outcomes. With diagnosis of GvHD reliant on its clinical manifestations, research into biomarkers for the diagnosis, progression, and even for the prediction of disease, is imperative to combating the high levels of morbidity and mortality post-HSCT. Despite the development of novel treatment approaches to GvHD, corticosteroids remain the standard first-line treatment, with immunosuppressant therapies as second-line options. These strategies however have significant limitations and associated complications. Extracorporeal Photopheresis (ECP) has shown to be effective and safe in treating patients with symptomatic GvHD. ECP has been shown to have varied effects on multiple parts of the immune system and does not appear to increase the risk of relapse or infection in the post HSCT setting. Even so, ECP can be logistically more complex to organize and requires patients to be sufficiently stable. This review aims to summarize the potential role of biomarkers to help guide individualized treatment decisions in patients with acute and chronic GvHD. In relation to ECP, robust biomarkers of GvHD will be highly useful in informing patient selection, intensity and duration of the ECP schedule, monitoring of response and other treatment decisions alongside the concurrent administration of other GvHD therapies. Further research is warranted to establish how GvHD biomarkers are best incorporated into ECP treatment pathways with the goal of tailoring ECP to the needs of individual patients and maximizing benefit.

Human Apoptotic Cells, Generated by Extracorporeal Photopheresis, Modulate Allogeneic Immune Response

The induction of specific and sustainable tolerance is a challenging issue in organ transplantation. The discovery of the immunosuppressive properties of apoptotic cells in animal models has paved the way for their use in human transplantation. In this work, we aimed to define a stable, reproducible, and clinically compatible production procedure of human apoptotic cells (Apo-cells). Using a clinically approved extracorporeal photopheresis technique, we have produced and characterized phenotypically and functionally human apoptotic cells. These Apo-cells have immunosuppressive properties proved in vitro and in vivo in NOD/SCID/γC mice by their capacity to modulate an allogeneic response following both a direct and an indirect antigen presentation. These results brought the rationale for the use of Apo-cells in tolerance induction protocol for organ transplantation.

Site-Specific Encoding of Photoactivity in Antibodies Enables Light-Mediated Antibody-Antigen Binding on Live Cells

Antibodies have found applications in several fields, including, medicine, diagnostics, and nanotechnology, yet methods to modulate antibody-antigen binding using an external agent remain limited. Here, we have developed photoactive antibody fragments by genetic site-specific replacement of single tyrosine residues with photocaged tyrosine, in an antibody fragment, 7D12. A simple and robust assay is adopted to evaluate the light-mediated binding of 7D12 mutants to its target, epidermal growth factor receptor (EGFR), on the surface of cancer cells. Presence of photocaged tyrosine reduces 7D12-EGFR binding affinity by over 20-fold in two out of three 7D12 mutants studied, and binding is restored upon exposure to 365 nm light. Molecular dynamics simulations explain the difference in effect of photocaging on 7D12-EGFR interaction among the mutants. Finally, we demonstrate the application of photoactive antibodies in delivering fluorophores to EGFR-positive live cancer cells in a light-dependent manner.

CD71 surface analysis of T cells: a simple alternative for extracorporeal photopheresis quality control

BACKGROUND

Extracorporeal photopheresis (ECP) is a leukapheresis-based cellular therapy that is used with increasing frequency worldwide to treat various T-cell-mediated diseases. Currently, the inhibition of T-cell proliferation after photopheresis is analysed frequently using time-consuming assays including radioactive thymidine assays or carboxyfluorescein succinimidyl ester (CFSE) staining. We investigated whether simple surface T-cell staining using surrogate markers of T-cell proliferation can replace time-consuming measurement of T-cell proliferation in ECP quality control.

STUDY DESIGN AND METHODS

T-cell activation markers were investigated by flow cytometry after ECP. Candidates were validated by direct comparison with the classical CFSE T-cell proliferation inhibition test and apoptosis staining. Finally, surface T-cell staining was performed in patient samples in comparison with classical methods.

RESULTS

CD71 expression exhibited the fastest and most robust upregulation, which was detectable as early as 6-8 h after T-cell stimulation and almost completely abrogated by ECP. In a direct comparison with the CFSE T-cell proliferation assay, suppression of CD71 expression after ECP was almost identical and detectable as early as 16 h after stimulation in peripheral blood mononuclear cells of healthy donors. Furthermore, in direct comparison with classical apoptosis staining, the inhibition delta of CD71 after ECP was significantly higher. Moreover, in patients under T-cell suppressive therapy, T-cell-dependent CFSE and CD71 assays exhibited decreased sensitivity to detect ECP treatment and were inferior in comparison to apoptosis staining.

CONCLUSION

Surface CD71 analysis represents a very simple quality control alternative to detect ECP-mediated T-cell proliferation inhibition in normal PBMC samples devoid of T-cell suppressive drugs.

Therapeutic apheresis in kidney transplantation: An updated review

Therapeutic apheresis is a cornerstone of therapy for several conditions in transplantation medicine and is available in different technical variants. In the setting of kidney transplantation, immunological barriers such as ABO blood group incompatibility and preformed donor-specific antibodies can complicate the outcome of deceased- or living- donor transplantation. Postoperatively, additional problems such as antibody-mediated rejection and a recurrence of primary focal segmental glomerulosclerosis can limit therapeutic success and decrease graft survival. Therapeutic apheresis techniques find application in these issues by separating and selectively removing exchanging or modifying pathogenic material from the patient by an extracorporeal aphaeresis system. The purpose of this review is to describe the available techniques of therapeutic aphaeresis with their specific advantages and disadvantages and examine the evidence supporting the application of therapeutic aphaeresis as an adjunctive therapeutic option to immunosuppressive agents in protocols before and after kidney transplantation.

[Single-center retrospective analysis of extracorporal photopheresis in clinical practice : Peripheral venous compared to central venous access]

BACKGROUND

Extracorporal photopheresis (ECP) was shown to be effective without severe side effects in the treatment of cutaneous T cell lymphoma (CTCL) and graft versus host disease (GvHD). However, only few studies investigated the practical aspects of ECP.

METHODS

Treatment protocols of 2038 ECP procedures in 52 patients (CTCL, n = 29; GvHD, n = 15; other, n = 8) were evaluated. The patients were treated with the UVAR® XTS™ ECP system (Therakos, Inc. Johnson & Johnson, Raritan, NJ, USA) between 2001 and 2010. All patients started with a peripheral venous access. During the course of treatment 7 patients were treated via a port and 4 via a central venous catheter.

RESULTS

In all, 1765 (86.6%) treatments were performed with a peripheral venous access; 239 (11.7%) ECPs were done via a port and 34 (1.7%) via a central venous catheter. The peripheral venous access showed a higher flow rate and longer photoactivation time. ECPs via port lead to higher UV-irradiated volumes, longer treatment times and higher differences in systolic blood pressure. The following side effects were observed: being unwell (n = 13), hypo- (n = 13) and hypertension (n = 7), vertigo (n = 4), headache (n = 4), shortness of breath (n = 4), fever (n = 3) and metallic taste (n = 3). Technical complications such as problems with venous access (9.6%) occurred in 385 (18.9%) treatments.

CONCLUSIONS

Peripheral venous access should be preferred for ECP treatments.

Leukaemic variants of cutaneous T-cell lymphoma: Erythrodermic mycosis fungoides and Sézary syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common types of cutaneous lymphoma, accounting for approximately 60% of cutaneous T-cell lymphomas. Diagnosis requires correlation of clinical, histologic, and molecular features. A multitude of factors have been linked to the aetiopathogenesis, however, none have been definitively proven. Erythrodermic MF (E-MF) and SS share overlapping clinical features, such as erythroderma, but are differentiated on the degree of malignant blood involvement. While related, they are considered to be two distinct entities originating from different memory T cell subsets. Differential expression of PD-1 and KIR3DL2 may represent a tool for distinguishing MF and SS, as well as a means of monitoring treatment response. Treatment of E-MF/SS is guided by disease burden, patients' ages and comorbidities, and effect on quality of life. Current treatment options include biologic, targeted, immunologic, and investigational therapies that can provide long term response with minimal side effects. Currently, allogeneic stem cell transplantation is the only potential curative treatment.

Mycosis fungoides and Sézary syndrome: 2019 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas (CTCL) are a heterogenous group of T-cell neoplasms 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

TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multi-disciplinary approach to treatment. For patients with disease limited to the skin, skin-directed therapies are 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 systemic therapies. These include biologic-response modifiers, histone deacetylase (HDAC) inhibitors, or antibody-based strategies, in an escalating fashion. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

Prolonged survival with the early use of a novel extracorporeal photopheresis regimen in patients with Sézary syndrome

Gao et al report that early use of extracorporeal photopheresis improves time to next treatment and survival in patients with Sézary syndrome.

Iron deficiency anemia associated with extracorporeal photopheresis: A retrospective analysis

BACKGROUND

Extracorporeal photopheresis (ECP) is associated with few adverse effects. We have anecdotally noted patients treated with long-term ECP develop iron deficiency anemia (IDA).

METHODS

We performed a retrospective chart review of adult patients who received ECP for any indication at Mayo Clinic Rochester and Mayo Clinic Arizona. The primary objective was to describe the cumulative incidence of IDA at 1 year of ECP therapy.

RESULTS

A total of 123 patients were eligible for analysis. Graft-vs-host disease was the most common indication for ECP (n = 76, 61.8%). At 1 year of ECP therapy, the cumulative incidence of IDA was 24.1% (95% CI, 14.2%-32.9%). At 5 years, the cumulative incidence of IDA was 68.3% (95% CI, 38%-83.8%). Risk factors for the development of IDA included: cumulative number of ECP sessions (HR 1.34, 95% CI, 1.05-1.73 per 10 additional sessions, P = .022), an indication for ECP of solid organ transplant rejection (compared to cutaneous T-cell lymphoma, HR 5.46, 95% CI, 2.06-14.49, P < .001), and proton pump inhibitor use at baseline (HR 2.15, 95% CI, 1.1-4.21, P = .03). Iron supplementation was initiated in 29 of 37 evaluable patients who developed IDA, with a cumulative incidence of supplementation in 77.2% patients within 3 months of recognition of IDA (95% CI, 55.8%-88.3%). Hemoglobin normalized in 50.1% of patients started on iron supplementation for IDA within 7 months (95% CI, 25.2%-66.7%).

CONCLUSIONS

Iron deficiency anemia is common in patients receiving long-term ECP and occurs throughout ECP therapy. IDA resolved with iron supplementation in half of patients.

Cutaneous Lymphomas

Primary cutaneous lymphomas are the second most common form of extra-nodal lymphomas. They have special characteristics compared with other lymphomas. They are most frequently of T-cell origin and they generally have a much more indolent course than lymphomas of similar histology in other locations. Mycosis fungoides is the most common type of cutaneous lymphoma. Primary cutaneous lymphomas remain confined to the skin for a long time. Skin-directed therapies are the main treatments; systemic treatments are not very effective for the skin lesions. Skin-directed therapies used for the early and thin lesions are topical corticosteroids, phototherapy and topical retinoids and, for the more widespread or thick lesions, topical nitrogen mustard and radiation. Radiation therapy is highly effective and is indicated in virtually all cases of localised disease. Radiation therapy may be given to the whole skin surface, so-called total skin electron beam therapy. However, if the disease spreads to other organs, systemic treatments are indicated, often combined with skin-directed therapies. Conventional cytotoxic therapy is less effective in cutaneous lymphomas. The commonly used therapies, such as interferon, enhanced anti-tumour immunity and the recent advances in immune therapies may improve our treatments for cutaneous lymphomas.

Extracorporeal photochemotherapy induces bona fide immunogenic cell death

Extracorporeal photochemotherapy (ECP) is employed for the management of cutaneous T cell lymphoma (CTCL). ECP involves the extracorporeal exposure of white blood cells (WBCs) to a photosensitizer, 8-methoxypsoralen (8-MOP), in the context of ultraviolet A (UVA) radiation, followed by WBC reinfusion. Historically, the therapeutic activity of ECP has been attributed to selective cytotoxicity on circulating CTCL cells. However, only a fraction of WBCs is exposed to ECP, and 8-MOP is inactive in the absence of UVA light, implying that other mechanisms underlie the anticancer effects of ECP. Recently, ECP has been shown to enable the physiological differentiation of monocytes into dendritic cells (DCs) that efficiently cross-present tumor-associated antigens (TAAs) to CD8⁺ T lymphocytes to initiate cognate immunity. However, the source of TAAs and immunostimulatory signals for such DCs remains to be elucidated. Here, we demonstrate that 8-MOP plus UVA light reduces melanoma cell viability along with the emission of ICD-associated danger signals including calreticulin (CALR) exposure on the cell surface and secretion of ATP, high mobility group box 1 (HMGB1) and type I interferon (IFN). Consistently, melanoma cells succumbing to 8-MOP plus UVA irradiation are efficiently engulfed by monocytes, ultimately leading to cross-priming of CD8⁺ T cells against cancer. Moreover, malignant cells killed by 8-MOP plus UVA irradiation in vitro vaccinate syngeneic immunocompetent mice against living cancer cells of the same type, and such a protection is lost when cancer cells are depleted of calreticulin or HMGB1, as well as in the presence of an ATP-degrading enzyme or antibodies blocking type I IFN receptors. ECP induces bona fide ICD, hence simultaneously providing monocytes with abundant amounts of TAAs and immunostimulatory signals that are sufficient to initiate cognate anticancer immunity.

Extracorporeal photopheresis for the treatment of graft rejection in 33 adult kidney transplant recipients

Background - Extracorporeal photopheresis (ECP) has shown encouraging results in the prevention of allograft rejection in heart transplantation. However, the role of ECP in kidney transplant (KT) rejection needs to be determined. Methods - This multicentre retrospective study included 33 KT recipients who were treated with ECP for allograft rejection (23 acute antibody-mediated rejections (AMRs), 2 chronic AMRs and 8 acute cellular rejections (ACRs)). The ECP indications were KT rejection in patients who were resistant to standard therapies (n = 18) or in patients for whom standard therapies were contraindicated because of concomitant infections or cancers (n = 15). Results - At 12 months (M12) post-ECP, 11 patients (33%) had a stabilization of kidney function with a graft survival rate of 61%. The Banff AMR score (g + ptc + v) was a risk factor for graft loss at M12 (HR 1.44 [1.01-2.05], p < 0.05). The factorial mixed data analysis identified 2 clusters. Patients with a functional graft at M12 tended to have cellular and/or chronic rejections. Patients with graft loss at M12 tended to have acute rejections and/or AMR; higher serum creatinine levels; DSA levels and histologic scores of AMR; and a longer delay between the rejection and ECP start than those of patients with functional grafts. Conclusions - ECP may be helpful to control ACR or moderate AMR in KT recipients presenting concomitant opportunistic infections or malignancies when it is initiated early.

Efficacy and safety of one-day offline extracorporeal photopheresis schedule processing one total blood volume for treating patients with graft-versus-host disease

BACKGROUND

Extracorporeal photopheresis (ECP) has been increasingly used as a second-line therapy for graft-versus-host disease (GVHD) but there is no consensus regarding the best therapeutic schedule.

STUDY DESIGN AND METHODS

Our offline ECP schedule for treating patients with GVHD was retrospectively reviewed. Patients with acute GVHD were treated on 2 days per week for the first 2 weeks, followed by 1 day per week for 2 more weeks. After the first month of treatment, patients received treatment 1 day every 2 weeks for a minimum of 16 ECP procedures. Patients with chronic GVHD were treated on 1 day per week for 4 weeks followed by 1 day every 2 weeks for a minimum of 14 ECP procedures.

RESULTS

Our series comprises 21 (45%) patients with acute GVHD and 26 (55%) patients with chronic GVHD who received 667 ECP procedures. A median (interquartile range [IQR]) of 1.0 (1.0-1.12) total blood volume was processed. Patients with acute and chronic GVHD received ECP procedures during a median of 49 (IQR, 14-103) and 180 (IQR, 111-274) days, respectively. Mild citrate-induced symptoms were present in 98 (46%) and 232 (51%) procedures in patients with acute and chronic GVHD, respectively. Overall response rate (ORR) and overall survival (OS) were 57 and 38% (95% confidence interval [CI], 17%-59%), respectively, for patients with acute GVHD. For patients with chronic GVHD, ORR and OS were 77 and 61% (95% CI, 18%-87%), respectively.

CONCLUSION

Our new offline ECP schedule for treating patients with acute and chronic GVHD was efficacious and safe.

Chemoirradiated neutrophils and T cells differentially affect immune functions of APCs

Extracorporeal photopheresis (ECP) is known as an immunomodulatory therapy with few side effects, which is mainly used in the treatment of cutaneous T cell lymphoma, graft-versus-host disease, and allograft rejection. During ECP, leukocytes are separated from whole blood by leukapheresis, subsequently chemoirradiated with 8-methoxypsoralen and UVA light, and re-infused into the patient. Although clinically effective, its mode of action has not been fully elucidated. In the present study, we analyzed the interaction of chemoirradiated neutrophils and CD3+ lymphocytes with APC in an in vitro model. We report that chemoirradiated CD3+ T cells induced increased expression of activation markers on dendritic cells (DC), macrophages, and monocytes. Coculture of chemoirradiated CD3+ T cells with these APC also led to significantly increased secretion of TNF-α. Although less pronounced, additional activation of APC took place when APC were stimulated with LPS or IFN-γ. In contrast, chemoirradiated neutrophils did not show activating effects on APC. The presence of chemoirradiated neutrophils during LPS and IFN-γ stimulation of DC rather diminished DC and macrophage activation. In line with these findings DC cocultured with chemoirradiated CD3+ T cells, but not neutrophils, showed significantly increased activation of CD3+ responder lymphocytes in a mixed lymphocyte reaction. With this study, we demonstrate that chemoirradiated leukocytes have differential indirect immunomodulatory effects. Whereas chemoirradiated CD3+ T cells activate APC, chemoirradiated neutrophils suppress activation of APC in the presence of other activating factors, suggesting that the composition of the ECP-treated buffy coat might be of importance for its immunomodulatory effects.

Blood transcriptional profiling reveals IL-1 and integrin signaling pathways associated with clinical response to extracorporeal photopheresis in patients with leukemic cutaneous T-cell lymphoma

Extracorporeal photopheresis (ECP) is a frontline therapy for patients with leukemic cutaneous T-cell lymphoma (L-CTCL), but its mechanisms of action are not fully understood. This study was to explore the molecular mechanisms underlying clinical response versus non-response in patients with L-CTCL. We performed blood transcriptional profiling of ten L-CTCL patients at Day 2 and 1 month post- ECP compared to pre-ECP baseline using Agilent Whole Human Genome Microarray technology. Differentially expressed genes (DEGs) between five clinically-responsive patients and five clinically-resistant patients were cross-compared. Higher numbers of genes were modulated in responders than non-responders after ECP at both Day 2 and 1 month, with two thirds of DEGs down-regulated. The down-regulated DEGs at 1 month post-ECP were related to inflammatory, immune and/or stress responses, platelet functions, and chromatin remodeling. Upregulated DEGs were mainly related to functions of the nucleolus. Pathway analysis revealed that integrin and IL-1 signaling pathways were the top pathways affected in responders, which were minimally affected in non-responders. The top upstream transcription regulators affected were IL1B, EGR1, FAS, and TGFB1. Our results suggest that the modulation of cell adhesion and suppression of IL-1β induced inflammation may underlie the efficacy of ECP in L-CTCL.

Higher response rates in patients with severe chronic skin graft-versus-host disease treated with extracorporeal photopheresis

Introduction

Different forms of graft-versus-host disease (GVHD) remain a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). The prognosis for steroid-refractory chronic GVHD (cGVHD) remains poor. Our aim was to evaluate extracorporeal photopheresis (ECP) treatment in cGVHD patients with different organ involvement to detect subgroups of patients with the best response.

Material and methods

Thirty-four patients who underwent HSCT and developed moderate (n = 7) or severe (n = 27) steroid-refractory or steroid-dependent cGVHD treated with ECP were included in the analysis. A matched cGVHD control patient group untreated with ECP was collected for comparison.

Results

Compared to the control group and the stable/progressive disease (SD/PD) patients, individuals with complete/partial remission have higher overall survival and lower transplant-related mortality. Furthermore, patients with complete and partial remission (CR/PR) had significantly higher levels of albumin and platelets after ECP treatment compared to patients with stable or progressive cGVHD (SD/PD). Corticosteroid treatment and other immunosuppressive agents could successfully be tapered in the CR/PR group compared to the SD/PD patients. In this study patients with skin cGVHD are those with the highest rate of CR/PR after ECP treatment.

Conclusions

Our results suggest that ECP treatment is safe and effective for patients with predominantly skin, oral and liver cGVHD.

A standardized methodical approach to characterize the influence of key parameters on the in vitro efficacy of extracorporeal photopheresis

Extracorporeal photopheresis (ECP) is an autologous immunomodulatory cell therapy that consists of the ex vivo collection of mononuclear cells (MNCs), which are irradiated with UVA in the presence of the photosensitizing agent 8-methoxypsoralen (8-MOP) to induce cell apoptosis. This photoactivated cell preparation is then reinfused into the patient. While the clinical benefits of ECP are well-demonstrated, no study has yet characterized the influence of variations in the composition of the cell preparation on the efficacy of ECP in vitro. Here, we describe a standardized methodology for the in vitro assessment of ECP that uses the human lymphoma T-cell line and mimics the clinical procedure. By quantifying cell apoptosis, inhibition of cell proliferation, and 8-MOP consumption, we used this approach to characterize the specific influence of key variables on the cellular response to ECP. We found that (i) increases in hematocrit and plasma concentrations attenuated the cellular response to ECP; (ii) plasma concentration was the only variable tested that influenced 8-MOP consumption; and (iii) the loss of efficacy due to variations in the concentration of certain blood components could be counteracted by modulating the UVA dose. This methodology may enable evaluation of other leukapheresis preparation protocols and better determination of the optimal working parameters for ECP.

Phototherapy of cutaneous T-cell lymphomas

Cutaneous T-cell lymphomas (CTCL) are a heterogenous group of non-Hodgkin lymphomas arising in the skin. Mycosis fungoides (MF), the most common variant, is characterised by clonal proliferation of skin residing malignant T-cells. Initially appearing with erythematous patches and plaques it follows a chronic course with progression to cutaneous tumours and extracutaneous involvement in some patients. Phototherapy with ultraviolet A radiation combined with 8-methoxypsoralen (PUVA) and with narrow-band ultraviolet B radiation (NB-UVB) are among the first line options for the treatment of MF and can induce remission in most patients. Sézary syndrome (SS) is a rare and more aggressive CTCL variant with generalized skin involvement. Patients with SS and with erythroderma from MF can benefit from treatment with extracorporeal photochemotherapy (ECP) where peripheral blood is exposed to PUVA. Phototherapy can be safely combined with systemic agents, most notably interferon-alpha and retinoids. Another photoresponsive CTCL variant is lymphomatoid papulosis (LP), a CD30+ lymphoproliferative disease characterised by chronically recurring papules. The disease responds favourably to PUVA but low dose methotrexate might be preferred for long term disease control. Recently updated treatment guidelines have been published to provide evidence-based algorithms for the stage-oriented treatment of MF, SS and LP. Areas of uncertainty are treatment schedules that are currently not optimised for CTCL, the use of phototherapy for maintenance, and the value of ultraviolet A1 radiation, excimer lasers, and photodynamic therapy.

Current Status of HDAC Inhibitors in Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of lymphomas that are characterized by primary skin involvement. Mycosis fungoides (MF) and Sézary syndrome (SS), the two most common subtypes of CTCL, can be difficult to manage clinically as there are few effective treatment options available. Recently, histone deacetylase inhibitors (HDACi) have emerged as promising therapies with favorable adverse effect profiles, compared with traditional chemotherapies. In this article, we review the published literature to evaluate the role of HDACi in the treatment of CTCL. Specifically, we (1) briefly discuss the molecular rationale for the use of HDACi in CTCL; (2) compare the efficacy, tolerability, and adverse effects of HDACi; (3) review the cardiac safety data; and (4) discuss optimization of therapy with HDACi in the treatment of CTCL.