ECP-treated lymphocytes of chronic graft-versus-host disease patients undergo apoptosis which involves both the Fas/FasL system and the Bcl-2 protein family

What Does the Future Hold for Biomarkers of Response to Extracorporeal Photopheresis for Mycosis Fungoides and Sézary Syndrome?

Extracorporeal photopheresis (ECP) is an FDA-approved immunotherapy for cutaneous T-cell lymphoma, which can provide a complete response in some patients. However, it is still being determined who will respond well, and predictive biomarkers are urgently needed to target patients for timely treatment and to monitor their response over time. The aim of this review is to analyze the current state of the diagnostic, prognostic, and disease state-monitoring biomarkers of ECP, and outline the future direction of the ECP biomarker discovery. Specifically, we focus on biomarkers of response to ECP in mycosis fungoides and Sézary syndrome. The review summarizes the current knowledge of ECP biomarkers, including their limitations and potential applications, and identifies key challenges in ECP biomarker discovery. In addition, we discuss emerging technologies that could revolutionize ECP biomarker discovery and accelerate the translation of biomarker research into clinical practice. This review will interest researchers and clinicians seeking to optimize ECP therapy for cutaneous T-cell lymphoma.

Novel Application of Extracorporeal Photopheresis as Treatment of Graft-versus-Host Disease Following Liver Transplantation

A 48-year-old man with hepatitis C virus (HCV) cirrhosis complicated by hepatocellular carcinoma underwent liver transplantation. His course was complicated by fever, diarrhea, abdominal pain, and pancytopenia. He developed a diffuse erythematous rash, which progressed to erythroderma. Biopsies of the colon and skin were consistent with acute graft-versus-host disease. Donor-derived lymphocytes were present in the peripheral blood. The patient was treated with corticosteroids and cyclosporine; however, he had minimal response to intensive immunosuppressive therapy. Extracorporeal photopheresis was initiated as a salvage therapy. He had a dramatic response, and his rash, diarrhea, and pancytopenia resolved. He is maintained on minimal immunosuppression 24 months later.

CD4+CD25+ Lymphocyte Subsets in Chronic Graft versus Host Disease Patients Undergoing Extracorporeal Photochemotherapy

Extracorporeal photochemotherapy (ECP) has been used successfully for the treatment of chronic Graft versus Host Disease (cGvHD). However, the mechanism by which ECP exerts its protective effects remains elusive. Some recent observations have suggested a possible role of certain subsets of T lymphocytes with immunosuppressive properties (T-regulatory cells) that coexpress CD4 and high levels of the interleukin-2 receptor chain: CD4+CD25+ T lymphocytes. We studied whether ECP affects the percentage of these cells in the peripheral blood of patients with cGvHD. The study population consisted of 14 patients with cGvHD refractory to systemic steroids. On enrolment in each cycle of ECP, patients underwent clinical examination, blood chemistry analysis and other instrumental procedures to document and assess involvement of the various organs and systems. For cytofluorimetric identification and phenotyping of CD4+CD25+ T lymphocytes, peripheral blood samples were collected in EDTA anticoagulant before ECP, after 48 hours, and after 6 and 12 months from the start of treatment. The 14 patients in this study received a total of more than 300 cycles of ECP, with only minor side effects. The clinical outcome was negative in 2 patients and positive in 12 patients. Within-subject analysis indicated that the percentage of CD4+CD25+ T lymphocytes before ECP and after 12 months of treatment was significantly increased. Our study confirms that changes in the percentage of CD4+CD25+ T cells induced by ECP could be a central aspect in the cascade of immune events leading to the immunological and clinical effects of this treatment in patients with cGvHD.

Extracorporeal photopheresis after heart transplantation

The addition of extracorporeal photopheresis (ECP) to a standard immunosuppressive drug therapy after heart transplantation in clinical studies has shown to be beneficial, for example, by reducing acute rejection, allograft vasculopathy or CMV infection. However, the protocols varied considerably, have a predetermined finite number of ECP treatments and adjuvant immunosuppressive regimens used in combination with ECP have differed significantly. Furthermore, there are scarce data to guide which patients should be treated with ECP and when or who would benefit further if ECP were to be continued long term to increase the safety by reducing immunosuppressive drug toxicities without losing efficacy. The knowledge of the tolerance-inducing effects of ECP-like upregulation of regulatory T cells and of dendritic cells may allow to develop a strategy to monitor immunomodulation effects of ECP to further identify ECP responders, the optimal individual ECP schedule and whether ECP therapy can replace or reduce immunosuppressive drug therapy.

Extracorporeal photopheresis as a therapy for autoimmune diseases

Systemic autoimmune diseases (AID) have multiorgan, heterogeneous clinical presentations and are characterized by dysregulation of the immune system, immunodeficiency, irreversible organ damage and increased morbidity and mortality. Preventing or decreasing flares of AID correlate with durable disease control, significant reduction of inflammation and prevention of disability or therapy-related toxicity. There is an urgent need for better treatment of severe, therapy-refractory AID. Extracorporeal photopheresis (ECP) is a cell-based immunomodulatory treatment which has been extensively used in variety of autoimmune disorders for the last two decades. ECP treatment is FDA approved for the treatment of cutaneous T-cell lymphoma (CTCL) with particularly promising results seen in graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HCT). Prolonged therapy is safe, well tolerated and allows reduction of systemic immunosuppression in therapy-refractory patients. Both clinical and experimental evidence suggest that ECP mechanism of action is characterized by apoptosis and phagocytosis of activated cells by antigen-presenting cells (APC), secretion of anti-inflammatory cytokines and stimulation of regulatory T cells (Tregs). The focus of this paper is to review the current evidence of ECP use in the treatment of AID. Here, we summarize the experience of nine major AID from 65 published reports. The key findings demonstrate substantial evidence of ECP feasibility, safety and in some AID also promising efficacy. However, the role of ECP in AID therapy is not established as most published studies are retrospective with limited number of patients and the trials are small or poorly standardized. The available data support future investigations of ECP as a therapeutic modality for the treatment of AID in well-designed prospective clinical studies. J

The molecular and clinical rationale of extracorporeal photochemotherapy in autoimmune diseases, malignancies and transplantation

Extracorporeal photochemotherapy, or photopheresis is a low-risk therapeutical intervention, which has been introduced in a variety of hematological malignancies, autoimmune conditions and transplantation. The mode of action of photopheresis encompasses apoptosis-induction and modifications of immunoregulatory processes, leading to the elimination of malignant cells, as well as the down-modulation of harmful immune responses. Although the beneficial effects of the therapy have been depicted in numerous studies, little is known about the exact benefits and the molecular mechanisms behind. The aim of the present review was to portray some aspects of the molecular and clinical rationale of extracorporeal photochemotherapy in autoimmune diseases, malignancies and transplantation, and to provide an overview of the treatment in the modern clinical management of these diseases.

Efficacy of narrowband UVB vs. PUVA in patients with early-stage mycosis fungoides

INTRODUCTION

Mycosis fungoides (MF) is a non-Hodgkin's T-cell lymphoma of the skin that often begins as limited patches and plaques with slow progression to systemic involvement. Narrowband ultraviolet (UV) B therapy has been proven to be an effective short-term treatment modality for clearing patch-stage MF. The effect of psoralen plus long-wave ultraviolet A (PUVA) in the treatment of patch- and plaque-type MF has also been thoroughly documented.

OBJECTIVES

The purpose of this study was to compare the efficacy and safety of narrowband UVB and PUVA in patients with early-stage MF.

METHODS

We analysed the response to treatment, relapse-free survival and irradiation dose in 114 patients with histologically confirmed early-stage MF (stage IA, IB and IIA).

RESULTS

A total of 95 patients were treated with PUVA (83.3%) and 19 with narrowband UVB (16.7%). With PUVA, 59 patients (62.1%) had a complete response (CR), 24 (25.3%) had a partial response (PR) and 12 (12.6%) had a failed response. Narrowband UVB led to CR in 12 (68.4%) patients, PR in 5 (26.3%) patients and a failed response in 1 (5.3%) patient. There were no differences in terms of time to relapse between patients treated with PUVA and those treated with narrowband UVB (11.5 vs. 14.0 months respectively; P = 0.816). No major adverse reactions were attributed to the treatment.

CONCLUSIONS

Our results confirm that phototherapy is a safe, effective and well-tolerated, first-line therapy in patients with early-stage cutaneous T-cell lymphoma, with prolonged disease-free remissions being achieved. It suggests that narrowband UVB is at least as effective as PUVA for treatment of early-stage MF.

Extracorporeal photopheresis affects co-stimulatory molecule expression and interleukin-10 production by dendritic cells in graft-versus-host disease patients

Graft-versus-host disease (GVHD) is a major complication of allogeneic bone marrow transplantation. Extracorporeal photochemotherapy (ECP) has been introduced as an alternative treatment for GVHD refractory to conventional immunosuppressive treatment, although its mechanism of action is not yet clear. We investigated, in seven GVHD patients, the effects of ECP on dendritic cell maturation and cytokine production in an in vitro model that could mimic the potential in vivo effect of reinfusion of ECP-treated peripheral blood mononuclear cells. The model was based on co-culture of ECP-treated lymphocytes with monocyte-derived dendritic cells (DCs) of the same patient. We found that the co-culture of ECP-treated lymphocytes with immature DCs reduced CD54, CD40 and CD86 mean fluorescence intensity (MFI) significantly after lipopolysaccharide (LPS) stimulation, without affecting human leucocyte antigen D-related and CD80 MFI. In the same co-culture model, DCs produced increased amounts of interleukin (IL)-10 when co-cultured with ECP-treated lymphocytes and stimulated with LPS, while IL-12 and tumour necrosis factor-alpha production were not affected. These results suggest that reinfusion of large numbers of autologous apoptotic lymphocytes is significant for the therapeutic outcome of ECP through down-regulation of co-stimulatory molecules on DCs, inducing non-fully mature DCs with a low signal 2 and up-regulation of IL-10, which is an immunosuppressive cytokine.

Extracorporeal photopheresis in graft-versus-host disease

Graft-versus-host disease (GvHD) is a common and often serious complication of hematopoietic stem cell transplantation. There are two major forms of GvHD: an acute form which develops in the first 100 days after HSCT, and a chronic form which develops later. Chronic GvHD is a multiorgan syndrome with many features of autoimmune diseases, such as sclerodermatous skin changes, cholestasis, pulmonary fibrosis, xerostomia, oral ulcerations, myositis and fasciitis. Unlike acute GvHD which is characterized by acute alloreactivity,the etiology of chronic GvHD is controversial and is believed to be either an extension of acute GvHD and/or a result of dysfunctional immune reconstitution with generation of autoantibodies and autoreactive T-cell clones. GvHD is usually treated with corticosteroids and other immunosuppressants which do not always succeed in arresting its evolution. Extracorporeal photochemotherapy has been used in patients with both acute and chronic GvHD.

Extracorporeal photopheresis: A focus on apoptosis and cytokines

Induction of apoptosis and changes to cytokine secretion patterns have been implicated in the mechanism of action of extracorporeal photopheresis (ECP). Lymphocyte apoptosis is initially detected in significant numbers prior to re-infusion and by 48 h post-ECP the majority of treated lymphocytes are apoptotic. The early apoptosis involves changes to mitochondrial function, reversal of the Bcl-2/Bax ratio and externalisation of phosphatidylserine. Apoptotic lymphocytes, observed from 20 h post-ECP, are associated with enhanced levels of CD95 and Fas-ligand. For cutaneous T cell lymphoma (CTCL), processing of the apoptotic lymphocytes, by suitable antigen presenting cells (APCs), is suggested to induce a clonal cytotoxic response which targets the malignant T cell population. Increased levels of TNFalpha and IFNgamma, observed post-ECP in monocytes and lymphocytes, respectively, are thought to further contribute to the proposed anti-tumour reaction seen in CTCL. However, down-regulation of pro-inflammatory cytokines and enhanced anti-inflammatory responses have been reported following ECP treatment. These immune responses may contribute to the tempering of the inflammatory conditions, such as graft versus host disease, which respond to ECP. Furthermore, untreated monocytes exposed to ECP-treated lymphocytes have also demonstrated a shift in monocyte cytokine-secretory pattern, toward one associated with immune tolerance. Recently, a mechanism of ECP-induced immune tolerance has been linked to the stimulation of the anti-inflammatory cytokines IL10 and TGFbeta by T regulatory cells, following the infusion of ECP-treated CD11c(+) APCs. Ultimately, the multifaceted responses, induced by ECP, may explain the diversity of clinical conditions that benefit.

Extracorporeal photochemotherapy for the treatment of steroid-resistant chronic GVHD

Chronic graft-versus-host disease (GVHD) is a major limitation of successful allogeneic hematopoietic stem cell transplantation (HSCT). Extracorporeal photochemotherapy (ECP) has been tested extensively in small cohorts of patients with chronic GVHD. In this study, we retrospectively evaluated 71 patients with severe chronic GVHD treated with ECP. Response rate was 61% (n = 43), and 14 patients had complete responses (CRs). The best responses were observed in skin, liver, oral mucosa, and eye. Factors affecting outcomes were assessed in the less heavily pretreated subgroup (n = 63). Thrombocytopenia was associated with a lower response rate (P = .04), and there was a trend toward a higher response rate in de novo chronic GVHD. At 6 months, a total of 27 (69%) of 39 patients who were alive continued to have a sustained response (CR 4 [10%] of 39, and partial response [PR] 23 [59%] of 39). The cumulative incidence of steroid discontinuation at 1 year was 22%. The overall survival since initiation of therapy was 53% at 1 year. Response to ECP and platelet count at initiation of therapy were the strongest predictors of nonrelapse mortality (NRM) on univariate analysis. Objective responses were observed in a substantial number of patients with both skin and visceral chronic GVHD failing corticosteroids and other immunosuppression.

Extracorporeal photopheresis affects interleukin (IL)-10 and IL-12 production by monocytes in patients with chronic graft-versus-host disease

BACKGROUND

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic bone marrow transplantation. Extracorporeal photopheresis (ECP) has recently been introduced as an alternative treatment for cases of cGVHD refractory to conventional immunosuppressive treatment, but its mechanism of action is not yet clear.

OBJECTIVES

To investigate in seven patients with cGVHD the effects of ECP on resistance of monocytes to apoptosis and on monocyte cytokine production.

METHODS

We designed an in vitro model that could mimic the potential in vivo effect of reinfusion of peripheral blood mononuclear cells treated by ECP. The model was based on coculture of ECP-treated lymphocytes with untreated monocytes from the same patient.

RESULTS

ECP did not accelerate spontaneous apoptosis of monocytes. However, ECP-treated monocytes produced increased amounts of interleukin (IL)-12. In contrast, IL-12 production by monocytes did not increase in cocultures, but IL-10 production was upregulated.

CONCLUSIONS

These results suggest that reinfusion of large numbers of autologous apoptotic lymphocytes is significant for the therapeutic outcome of ECP through upregulation of IL-10, which is an immunosuppressive cytokine.

Mechanism of action of extracorporeal photochemotherapy in chronic graft-versus-host disease

Chronic graft-versus-host disease (GvHD) affects 50% of long-term bone marrow transplant survivors and remains a cause of major long-term morbidity in these patients despite aggressive therapy. Extracorporeal photochemotherapy (ECP), considered as an effective treatment for patients with erythrodermic cutaneous T-cell lymphoma (CTCL), has recently been used successfully in the treatment of GvHD. One of the most intriguing aspects of ECP is its ability to induce two apparently opposite effects: activation of the immune system against neoplastic cells (as in CTCL) and downregulation of the activity of T-cell clones in autoimmune diseases (as in systemic sclerosis, systemic lupus erythematosus and pemphigus vulgaris) and autoallogeneic immune responses (as in GvHD and allograft rejection). Only a better and more complete understanding of the various mechanisms involved will enable this interesting new therapy to be made more effective and selective.