Extracorporeal photochemotherapy induces arginase 1 in patients with graft versus host disease

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.

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.

Modulation and Apoptosis of Neutrophil Granulocytes by Extracorporeal Photopheresis in the Treatment of Chronic Graft-Versus-Host Disease

Chronic graft-versus-host disease (cGVHD) is a common side effect of allogeneic stem cell transplantation and a major cause of morbidity and mortality in affected patients. Especially skin, eyes and oral mucosa are affected. This can lead to pain and functional impairment. Extracorporeal photopheresis (ECP) is an effective immunomodulatory therapy with minimal side effects but its mode of action is still largely unknown. The objective of the present study was to examine the effects of ECP on neutrophil granulocytes in patients with cGVHD. Analysis of leukocytes from cGVHD patients obtained from the ECP device during treatment showed that neutrophil granulocytes account for the majority of cells treated during ECP. Neutrophils from healthy donors treated in vitro with 8-methoxypsoralen and UVA light as well as neutrophils from buffy coats of patients with cGVHD treated by ECP showed increased apoptosis and decreased half-life. In remaining non-apoptotic cells chemoirradiation resulted in loss of activation markers and reduced effector functions. This was accompanied by an increase in extracellular arginase-1 activity. Additional comparison of neutrophils isolated from blood of cGVHD patients before and 24h after ECP revealed a decreased half-life and reduction of effector functions of post-ECP neutrophils ex vivo. These observations strongly suggest that ECP induces both apoptosis and physiological changes in neutrophils and that these changes also take place in vivo. This study is the first to show that ECP modulates apoptosis and inflammatory activity in neutrophil granulocytes, indicating that neutrophils may significantly contribute to the overall immunomodulatory effects attributed to this treatment.

Immunonutrition stimulates immune functions and antioxidant defense capacities of leukocytes in radiochemotherapy-treated head & neck and esophageal cancer patients: A double-blind randomized clinical trial

BACKGROUND

Immunonutrition has been reported to improve the immune status of perioperative cancer patients, thereby reducing complications and length of hospital stay.

AIM

This study aimed to assess whether immunonutrition enriched in arginine, EPA & DHA and nucleotides could impact the immune cells responses in head & neck and esophageal cancer patients treated by radiochemotherapy (RCT).

METHODS

A double-blind clinical trial was carried out in 28 patients randomized into two groups, receiving either an immunomodulating enteral nutrition formula (IEN, n = 13, Impact(®), Nestlé) or an isoenergetic isonitrogenous standard enteral nutrition formula (SEN, n = 15) throughout RCT (5-7 weeks). After isolation from whole blood, immune cells metabolism and functions were assessed at the beginning (Db) and at the end (De) of RCT.

RESULTS

Immunonutrition maintained CD4(+)/CD8(+) T-lymphocyte counts ratio and CD3 membrane expression between Db and De. Polymorphonuclear cells CD62L and CD15 densities and ROS production were increased in IEN patients. Peripheral blood mononuclear cells (PBMC) production of pro-inflammatory prostaglandin-E2 was stable in IEN patients and lower than in SEN patients at De. Genes coding for immune receptors, antioxidant enzymes and NADPH oxidase subunits were overexpressed in the PBMC of IEN vs SEN patients at De.

CONCLUSION

Immunonutrition can enhance immune cell responses through the modulation of their phenotypes and functions. By modulating the gene expression of immune cells, immunonutrition could make it easier for the organism to adapt to the systemic inflammation and oxidative stress induced by RCT.

CLINICAL TRIAL REGISTRATION

This clinical trial has been registered on ClinicalTrial.gov website: NCT00333099.

Recent advances on cellular therapies and immune modulators for graft-versus-host disease

The efficacy of allogeneic hematopoietic stem cell transplantation is counterbalanced by the occurrence of life-threatening immune-mediated complications, such as graft-versus-host disease (GVHD), a multistep disease which is reportedly fatal to approximately 15% of transplant recipients. It is now established that T-cell-dendritic cell interactions, T-cell activation, release of proinflammatory cytokines and T-cell trafficking partake in GVHD pathogenesis. This article will focus on the most recent strategies aimed at preventing/treating GVHD by manipulating components of the innate and adaptive immune response from both the donor and the host.

Guidelines on the use of extracorporeal photopheresis

BACKGROUND

After the first investigational study on the use of extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma was published in 1983 with its subsequent recognition by the FDA for its refractory forms, the technology has shown significant promise in the treatment of other severe and refractory conditions in a multi-disciplinary setting. Among the major studied conditions are graft versus host disease after allogeneic bone marrow transplantation, systemic sclerosis, solid organ transplant rejection and inflammatory bowel disease.

MATERIALS AND METHODS

In order to provide recognized expert practical guidelines for the use of this technology for all indications the European Dermatology Forum (EDF) 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.

RESULTS AND CONCLUSION

These 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.

Extracorporeal photopheresis (photochemotherapy) in the treatment of acute and chronic graft versus host disease: immunological mechanisms and the results from clinical studies

Extracorporeal photopheresis (ECP) is an immunomodulatory alternative for treatment of graft versus host disease (GVHD). The blood is then separated into its various components through apheresis; buffy coat cells are thereafter treated with 8-methoxypsoralen before exposure to ultraviolet light and finally reinfused into the patient. There is a general agreement that this treatment has an anti-GVHD effect, but the mechanisms of action behind this effect are only partly understood. However, altered maturation of dendritic cells (DC) and thereby indirect modulation of T-cell reactivity seems to be one important mechanism together with DC-presentation of antigens derived from apoptotic donor T cells and induction of regulatory T cells. The treatment has been best studied in patients with chronic GVHD (both pediatric and adult patients), but most studies are not randomized and it is difficult to know whether the treatment is more effective than the alternatives. The clinical studies of ECP in adults with acute GVHD are few and not randomized; it is not possible to judge whether this treatment should be a preferred second- or third-line treatment. There is no evidence for increased risk of leukemia relapse or suppression of specific graft versus leukemia reactivity by this treatment, so specific antileukemic immunotherapy may still be possible. Thus, even though the treatment seems effective in patients with GVHD, further clinical (especially randomized) as well as biological studies with careful standardization of the treatment are needed before it is possible to conclude how ECP should be used in acute and chronic GVHD.

Immunonutrition improves functional capacities in head and neck and esophageal cancer patients undergoing radiochemotherapy: a randomized clinical trial

BACKGROUND & AIMS

Malnutrition is frequent in head and neck (HN) and esophageal cancer patients and aggravated by radiochemotherapy (RCT), increasing morbi-mortality and treatment toxicity. Our goal was to investigate the effect of immunonutrition consisting of an arginine, omega-3 fatty acid, nucleotides-enriched diet on nutritional status, and functional capacity in HN or esophageal cancer patients undergoing RCT.

METHODS

37 patients were randomized in a double-blind clinical trial. 5 days before and until the end of RCT (5-7 weeks), they received either an Immunomodulating Enteral Nutrition (IEN) or an isonitrogenous, isoenergetic Standard Enteral Nutrition (SEN). Anthropometrical parameters, nutritional risk index (NRI), serum albumin, plasma antioxidant capacity, and functional capacity were recorded between the beginning and the end of RCT.

RESULTS

A significant gain in total body weight (+2.1 ± 3.1 kg) was observed in IEN patients. Albuminemia and NRI were improved concomitantly in IEN malnourished patients. Plasma antioxidant capacity was improved (+100 ± 13 μM EqTrolox) in IEN patients. Functional capacity measured by WHO Performance Status and Karnofsky index was maintained in IEN patients but significantly reduced in SEN patients.

CONCLUSIONS

These preliminary data show that immunonutrition could improve the nutritional status together with functional capacity in HN and esophageal cancer patients undergoing RCT.

CLINICAL TRIAL REGISTRATION

This clinical trial promoted by the University Hospital Center of Clermont-Ferrand has been registered at ClinicalTrial.gov website under the following reference: NCT00333099.

Altered functions of natural killer cells in response to L-Arginine availability

L-Arginine (L-Arg) availability is crucial in the regulation of immune response. Indeed, L-Arg deficiency induces T-cell dysfunction and could modulate the properties of natural killer (NK) cells involved in the early host defense against infections and tumors. We explored the impact of L-Arg depletion on NK cell functions using two models - an NK-92 cell line and isolated human blood NK cells. Below 5mg/L of L-Arg, NK-92 cell proliferation was decreased and a total L-Arg depletion reduced NK-92 cell viability. NK cell cytotoxicity was significantly inhibited in presence of low L-Arg concentration (2.5 mg/L). L-Arg depletion reduced the expression of NK-92 activating receptors, NKp46 and NKp30, the expression of NK ζ chain and the NK-92 intracellular production of IFN-γ. Whatever the L-Arg concentrations tested, no significant variation in the gene expression of transporters and enzymes involved in L-Arg metabolism was found. Thus, L-Arg availability modulates the phenotypic and functional properties of NK cells.