Immunomodulatory effects of extracorporeal photochemotherapy in patients with extensive chronic graft-versus-host disease

Second line extracorporeal photopheresis for cortico-resistant acute and chronic GVHD after allogeneic hematopoietic cell transplantation for hematological malignancies: Long-term results from a real-life study

BACKGROUND & OBJECTIVES

The primary objective of this observational study was to perform an exhaustive description concerning patients receiving extracorporeal photopheresis (ECP) as second line treatment after steroid resistance for either acute or chronic GVHD following allo-HCT, secondary objectives were to evaluate the efficacy and long-term outcomes.

STUDY DESIGN

A total of 106 patients were included, 65 (61%) males and 41 (39%) females with a median age at transplantation of 52 years (range: 20-67). ECP was initiated after transplantation either for acute GVHD [N = 25 (24%), 12 grade III and 13 grade IV] affecting skin alone (N = 5), gut alone (N = 12), gut and liver (N = 8), or chronic GVHD [N = 81 (76%), 15 (14%) limited and 66 (62%) extensive].

RESULTS

Among the 25 patients treated for acute GHVD, 67% were responders and among the 81 patients with chronic GVHD, 78% were responders. Patients with acute GVHD had a median OS of 6 months with a survival probability at 2 years of 35% [95%CI: 14-56]. Patients with chronic GVHD had a median OS of 72 months with a survival probability at 2 years of 68% [95%CI: 56-78]. There was a significant difference in terms of survival for patients responding to ECP compared to non-responders in both acute and chronic GVHD forms. Acute GVHD grade III-IV, negatively impacted on OS (HR=7.77, 95%CI: 1.7-34), p = 0.007 and on disease relapse HR= 5.88, 95%CI: 1.7-20, p = 0.005.

CONCLUSION

We demonstrated that ECP is an effective treatment for GVHD in a good proportion of patients with high overall response rate.

Boost of innate immunity cytokines as biomarkers of response to extracorporeal photopheresis in patients with leukaemic cutaneous T-cell lymphoma

BACKGROUND

Extracorporeal photopheresis (ECP) has emerged as a systemic first-line immunomodulatory therapy in leukaemic cutaneous T-cell lymphoma (L-CTCL) and is now beginning to be utilized in other T-cell-mediated diseases. Although ECP has been used for nearly 30 years, its mechanisms of action are not sufficiently understood, and biomarkers for response are scarce.

OBJECTIVES

We aimed to investigate the immunomodulatory effects of ECP on cytokine secretion patterns in patients with L-CTCL, to help elucidate its mechanism of action.

METHODS

A total of 25 patients with L-CTCL and 15 healthy donors (HDs) were enrolled in this retrospective cohort study. Concentrations of 22 cytokines were simultaneously quantified by using multiplex bead-based immunoassays. Neoplastic cells in patients' blood were evaluated by flow cytometry.

RESULTS

Firstly, we observed a distinct cytokine profile pattern difference between L-CTCLs and HDs. There was a significant loss of tumour necrosis factor (TNF)-α, and significant increase of interleukins (IL)-9, IL-12 and IL-13 in the sera of patients with L-CTCL compared with HDs. Secondly, patients with L-CTCL who received ECP were classified as treatment responders and nonresponders according to the quantitative reduction of malignant burden in their blood. We evaluated cytokine levels in culture supernatants from patients' peripheral blood mononuclear cells (PBMCs) at baseline and 27 weeks after ECP initiation. Strikingly, PBMCs purified from ECP responders released statistically higher concentrations of innate immune cytokines IL-1α, IL-1β, granulocyte-macrophage colony-stimulating factor (GM-CSF) and TNF-α in comparison with ECP nonresponders. In parallel, responders showed clearance of erythema, reduction of malignant clonal T cells in the blood, and a potent boost of relevant innate immune cytokines in individual patients with L-CTCL.

CONCLUSIONS

Taken together, our results demonstrate that ECP stimulates the innate immune network, and facilitates redirection of the tumour-biased immunosuppressive microenvironment towards proactive antitumour immune responses. The alterations of IL-1α, IL-1β, GM-CSF and TNF-α can be used as biomarkers of response to ECP in patients with L-CTCL.

Effect of extracorporeal photopheresis on survival in acute graft versus host disease

BACKGROUND

Extracorporeal photopheresis (ECP) is the main non-pharmacological approach accompanying systemic medical treatments in steroid-resistant acute or chronic graft versus host disease. The study aimed to examine the effect of ECP on survival in acute graft versus host disease (aGVHD).

METHODS

A total of 35 patients who were followed up in the adult hematology clinic of İnönü University Turgut Özal Medical Center for aGVHD were included in the study. Stem cell transplantation and ECP application parameters that may affect the survival of the patients were examined.

RESULTS

In aGVHD using ECP, the degree of involvement affects survival. Involvements with a clinical and laboratory score (Glucksberg system) of 2 and above significantly reduced survival. The duration of ECP use is associated with survival. Especially, 45 days and longer use increases survival (hazard ratio, P-value <.05). The duration of steroid use was found to be effective in survival in aGVHD (P < .001). ECP administration day (P = .003), duration of steroid use (P < .001), duration of ECP use (P = .001), and grade of aGVHD (P < .001) affect survival.

CONCLUSION

ECP use is effective in survival in patients with aGVHD score ≥2. In patients with aGVHD, especially the use of 45 days and longer has a positive effect on survival. The duration of steroid use is associated with survival in aGVHD.

Take a spin: Apheresis in the care of adult leukaemia patients

Apheresis is an automated process to separate the whole blood of a patient or a donor, collect or remove specific blood components, and return the remaining back to the individual. Apheresis is an integral part of blood and marrow transplantation and has been increasingly utilized in novel cellular therapies for a variety of blood disorders. This review uses clinical cases to highlight the multiple roles of apheresis in the care of adult leukaemia patients, including therapeutic leukapheresis in hyperleukocytosis, mobilized peripheral blood hematopoietic progenitor cell collection in donors, mononucleated cell collection in preparation of donor lymphocyte infusion or chimeric antigen receptor T cells manufacture, and extracorporeal photopheresis in the treatment of graft versus host diseases.

Hematopoietic Cell Transplantation, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology

Hematopoietic cell transplantation (HCT) involves the infusion of hematopoietic progenitor cells into patients with hematologic disorders with the goal of re-establishing normal hematopoietic and immune function. HCT is classified as autologous or allogeneic based on the origin of hematopoietic cells. Autologous HCT uses the patient's own cells while allogeneic HCT uses hematopoietic cells from a human leukocyte antigen-compatible donor. Allogeneic HCT is a potentially curative treatment option for patients with certain types of hematologic malignancies, and autologous HCT is primarily used to support patients undergoing high-dose chemotherapy. Advances in HCT methods and supportive care in recent decades have led to improved survival after HCT; however, disease relapse and posttransplant complications still commonly occur in both autologous and allogeneic HCT recipients. Allogeneic HCT recipients may also develop acute and/or chronic graft-versus-host disease (GVHD), which results in immune-mediated cellular injury of several organs. The NCCN Guidelines for Hematopoietic Cell Transplantation focus on recommendations for pretransplant recipient evaluation and the management of GVHD in adult patients with malignant disease.

Immunomodulatory Therapies for the Treatment of Graft-versus-host Disease

Allogeneic hematopoietic stem cell transplantation (allo-HCT) is a potentially curative therapy for patients suffering from hematological malignancies, and its therapeutic success is based on the graft-versus-leukemia (GvL) effect. Severe acute and chronic graft-versus-host disease (GvHD) are life-threatening complications after allo-HCT. To date, most of the approved treatment strategies for GvHD rely on broadly immunosuppressive regimens, which limit the beneficial GvL effect by reducing the cytotoxicity of anti-leukemia donor T-cells. Therefore, novel therapeutic strategies that rely on immunomodulatory rather than only immunosuppressive effects could help to improve patient outcomes. Treatments should suppress severe GvHD while preserving anti-leukemia immunity. New treatment strategies include the blockade of T-cell activation via inhibition of dipeptidyl peptidase 4 and cluster of differentiation 28-mediated co-stimulation, reduction of proinflammatory interleukin (IL)-2, IL-6 and tumor necrosis factor-α signaling, as well as kinase inhibition. Janus kinase (JAK)1/2 inhibition acts directly on T-cells, but also renders antigen presenting cells more tolerogenic and blocks dendritic cell-mediated T-cell activation and proliferation. Extracorporeal photopheresis, hypomethylating agent application, and low-dose IL-2 are powerful approaches to render the immune response more tolerogenic by regulatory T-cell induction. The transfer of immunomodulatory and immunosuppressive cell populations, including mesenchymal stromal cells and regulatory T-cells, showed promising results in GvHD treatment. Novel experimental procedures are based on metabolic reprogramming of donor T-cells by reducing glycolysis, which is crucial for cytotoxic T-cell proliferation and activity.

[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.

Ruxolitinib-ECP combination treatment for refractory severe chronic graft-versus-host disease

Glucocorticoid-refractory (SR) chronic (c) graft-versus-host disease (GVHD) is a multisystem immunological disease and the leading cause of non-relapse mortality (NRM) in patients surviving longer than 2 years after allogeneic hematopoietic cell transplantation. Both ruxolitinib (RUX) and extracorporeal photopheresis (ECP) have shown activity for SR-cGVHD which motivated us to treat refractory cGHVD patients with the RUX-ECP combination. In this retrospective survey, 23 patients received RUX-ECP as salvage therapy for SR-cGVHD. The best response (CR or PR) at any time point during treatment was 74% (17/23) including 9% (2/23) CR and 65% (15/23) PR. The 24-months-survival was 75% (CI 56.0-94.1). Newly diagnosed cytopenia occurred in 22% (5/23) and CMV reactivation was observed in 26% (6/23) of the patients. Serum levels of soluble interleukin-2 receptor (sIL-2R) correlated with response. Our retrospective analysis shows that the RUX-ECP combination is safe and has activity in a fraction of patients with SR-cGVHD, which needs validation in a prospective trial.

Efficacy and immunologic effects of extracorporeal photopheresis plus interleukin-2 in chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) affects >50% of hematopoietic stem cell transplant patients. Extracorporeal photopheresis (ECP), an immunomodulatory therapy, provides clinical benefit in steroid-refractory (SR) cGVHD, possibly via regulatory T (T_reg) and natural killer (NK) cell expansion. We demonstrated that low-dose interleukin-2 (IL2) led to clinical improvement in SR-cGVHD and stimulated preferential T_reg and NK-cell expansion with minimal effect on conventional T (T_con) cells. We evaluated the effect of ECP (weeks 1-16) plus IL2 (1 × 10⁶ IU/m², weeks 9-16) in 25 adult patients with SR-cGVHD in a prospective phase 2 trial. Objective responses occurred in 29% and 62% of evaluable patients at weeks 8 (ECP alone) and 16 (ECP plus IL2), respectively. Eight weeks of ECP alone was associated with a marked decline in CD4⁺ T_con (P = .03) and CD8⁺ T cells (P = .0002), with minimal change in T_reg cells, T_reg:T_con cell ratio, or NK cells. Adding IL2 induced an increase in T_reg cells (P < .05 at weeks 9-16 vs week 8), T_reg:T_con cell ratio (P < .0001 at weeks 9-16 vs week 8), and NK cells (P < .05 at weeks 9-16 vs week 8). Patients responding to ECP alone had significantly fewer CD4⁺ T_con and CD8⁺ T cells at baseline compared with patients who responded after IL2 addition and patients who did not respond; neither T_reg nor NK cells were associated with response to ECP alone. Altogether, ECP plus IL2 is safe and effective in patients with SR-cGVHD. ECP and IL2 have distinct immunologic effects, suggesting different therapeutic mechanisms of action. This trial was registered at www.clinicaltrials.gov as #NCT02340676.

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.

Shaping of CD56bri Natural Killer Cells in Patients With Steroid-Refractory/Resistant Acute Graft-vs.-Host Disease via Extracorporeal Photopheresis

CD56^bri natural killer (NK) cells play an important role in the pathogenesis of graft-vs. -host disease (GVHD) and immune defense in the early period after allogeneic hematopoietic stem cell transplantation. Extracorporeal photopheresis (ECP) as an immunomodulating therapy has been widely used for GVHD treatment. However, the mechanism of action of ECP still remains to be elucidated, particularly the influence of ECP on NK cells. Thirty-four patients with steroid-refractory/resistant acute GVHD (aGVHD) ≥ °II and moderate to severe chronic GVHD (cGVHD) received ECP therapy. Patient samples obtained during intensive and long-term treatment were analyzed. Immunomonitoring with respect to cell phenotype and function was performed on rested peripheral blood mononuclear cells (PBMCs) using multiparametric flow cytometry. NK activity in terms of cytokine release was analyzed by intracellular cytokine staining after co-culture with K562 cells. Moreover, the proliferative capacity of NK cells, CD4⁺, and CD8⁺ T cells was determined by carboxyfluorescein succinimidyl ester (CFSE) staining. Clinically, 75% of aGVHD and 78% of cGVHD patients responded to ECP therapy. Moreover, our data show that aGVHD, cGVHD patients and healthy donors (HDs) present distinct NK patterns: aGVHD patients have a higher frequency of CD56^bri NK subsets with stronger NKG2D and CD62L expression, while CD56⁻CD16⁺ NK cells with higher expression of CD57 and CD11b stand out as a signature population for cGVHD. ECP therapy could significantly decrease CD56^briCD16⁻ NK cells with shifting the quality from a cytotoxic to a regulatory pattern and additionally mature CD56^dim NK cells via upregulation of CD57 in complete responding aGVHD patients. Moreover, ECP could keep the anti-viral and anti-leukemic effects intact via maintaining specialized anti-viral/leukemic CD57⁺NKG2C⁺CD56^dim NK cells as well as remaining the quality and quantity of cytokine release by NK cells. The proliferative capacity of effector cells remained constant over ECP therapy. In conclusion, ECP represents an attractive option to treat GVHD without compromising anti-viral/leukemic effects. Shaping of CD56^bri NK cell compartment by downregulating the cytotoxic subset while upregulating the regulatory subset contributes to the mechanisms of ECP therapy in aGVHD.

Modulation of B Cells and Homing Marker on NK Cells Through Extracorporeal Photopheresis in Patients With Steroid-Refractory/Resistant Graft-Vs.-Host Disease Without Hampering Anti-viral/Anti-leukemic Effects

Graft-vs.-host disease (GvHD), a severe complication of allogeneic hematopoietic stem cell transplantation, significantly affects the post-transplant morbidity and mortality. Systemic steroids remain the gold standard for the initial management of GvHD. However, up to 60% of patients will not sufficiently respond to steroids. Extracorporeal photopheresis (ECP), a cell-based immunotherapy, has shown good clinical results in such steroid-refractory/resistant GvHD patients. Given its immunomodulatory, but not global immunosuppressive and steroid-sparing capacity, ECP constitutes an attractive option. In the case of GvHD, the balance of immune cells is destroyed: effector cells are not any longer efficiently controlled by regulatory cells. ECP therapy may restore this balance. However, the precise mechanism and the impact of ECP on anti-viral/anti-leukemic function remain unclear. In this study, 839 ECP treatments were performed on patients with acute GvHD (aGvHD) and chronic GvHD (cGvHD). A comprehensive analysis of effector and regulatory cells in patients under ECP therapy included multi-parametric flow cytometry and tetramer staining, Luminex^TM-based cytokine, interferon-γ enzyme-linked immunospot, and chromium-51 release assays. Gene profiling of myeloid-derived suppressor cells (MDSCs) was performed by microarray analysis. Immunologically, modulations of effector and regulatory cells as well as proinflammatory cytokines were observed under ECP treatment: (1) GvHD-relevant cell subsets like CD62L⁺ NK cells and newly defined CD19^hiCD20^hi B cells were modulated, but (2) quantity and quality of anti-viral/anti-leukemic effector cells were preserved. (3) The development of MDSCs was promoted and switched from an inactivated subset (CD33^-CD11b⁺) to an activated subset (CD33⁺CD11b⁺). (4) The frequency of Foxp3⁺CD4⁺ regulatory T cells (Tregs) and CD24⁺CD38^hi regulatory B cells was considerably increased in aGvHD patients, and Foxp3⁺CD8⁺ Tregs in cGvHD patients. (5) Proinflammatory cytokines like IL-1β, IL-6, IL-8, and TNF-α were significantly reduced. In summary, ECP constitutes an effective immunomodulatory therapy for patients with steroid-refractory/resistant GvHD without impairment of anti-viral/leukemia effects.

Extracorporeal Photopheresis-An Overview

Extracorporeal photopheresis (ECP) has been in clinical use for over three decades after receiving FDA approval for the palliative treatment of the Sézary Syndrome variant of cutaneous T-cell lymphoma (CTCL) in 1988. After the first positive experiences with CTCL, additional indications have been successfully explored including areas such as graft-vs.-host disease (GVHD), scleroderma, and solid organ transplantation. The mechanism of action is still not fully resolved, but important steps in understanding ECP in recent years have been very informative. Originally, the primary hypothesis stated that psoralen and ultraviolet A (UVA) in combination induce apoptosis in the treated immune cells. This view shifted in favor of dendritic cell initiation, modification of the cytokine profile and stimulation of several T-cell lineages, in particular regulatory T-cells. A number of ECP guidelines have been produced to optimize treatment regimens in the clinical context. In CTCL, enough evidence is available for the use of ECP as a first line treatment for Sézary Syndrome (SS), but also as a second line or rescue treatment in therapy-refractory forms of mycosis fungoides (MF). ECP in the treatment of acute and chronic GVHD has shown promising results as second line therapy in steroid-refractory presentations. In solid organ transplantation, ECP has been used to increase tissue tolerance and decrease infections with opportunistic pathogens, attributed to the use of high doses of immunosuppressive medication. Infection with cytomegalovirus (CMV) remains a limiting factor affecting survival in solid organ transplantation and the role of ECP will be discussed in this review. A trend toward prophylactic use of ECP can be observed and may further contribute to improve the outcome in many patients. To further deepen our knowledge of ECP and thus facilitate its use in patients that potentially benefit most from it, future prospective randomized trials are urgently needed in this rapidly growing field. The aim of this review is to (1) introduce the method, (2) give an overview where ECP has shown promising effects and has become an essential part of treatment protocols, and (3) to give recommendations on how to proceed in numerous indications.

Extracorporeal photopheresis for graft versus host disease: Identifying a clinical pathway and associated resource utilization

Extracorporeal photopheresis (ECP) is an established therapy for the treatment of graft-versus-host-disease (GVHD) following an allogeneic stem cell transplant. We performed a prospective analysis of patients receiving ECP treatment for GVHD to identify a clinical pathway and resource utilization of this process. The cohort included consecutive allogeneic stem cell recipients with GVHD. ECP was performed using the CELLEX Photopheresis System or the UVAR XTS Photopheresis System (Therakos, Inc, Exton, PA). A clinical pathway was developed and a time and motion study was conducted to define the resource utilization and costs associated with ECP. Patients were treated with either CELLEX (n = 18 procedures) or UVAR (n = 4 procedures). Total time commitment for each procedure for the 2 machines differed. The time for ECP was 117 min (median, range: 91-164 min) using CELLEX and 161 min (median; range: 140-210) using the UVAR-XTS machine. Total costs of each ECP procedure were $3420.50. There is a considerable time commitment of the patient and the clinical staff when employing ECP to treat GVHD. ECP costs are significant considering this is a prolonged therapy continued for several months. With this finalized pathway and costs, we have a standardized clinical pathway for the treatment of GVHD. We are addressing minimizing resource utilization while emphasizing quality care for these patients.

In vitro effects of different 8-methoxypsoralen treatment protocols for extracorporeal photopheresis on mononuclear cells

Extracorporeal photopheresis (ECP) is an important second-line therapy for graft-versus-host disease. A central therapeutic mechanism is the induction of immune tolerance through apoptosis in patient’s leukocytes, caused by ex vivo incubation with 8-methoxypsoralen (8-MOP) and subsequent UVA irradiation.

We hypothesized that different 8-MOP incubation times and an additional 8-MOP removal step could influence the apoptosis kinetics of leukocytes in general and in particular could lead to different apoptotic levels in the leukocyte subpopulations. After 8-MOP/UVA treatment of human leukocytes, cells were cultured and the percentage of annexin V positive cells from several leukocyte subpopulations was determined. Only regulatory T cells (Tregs) were relatively resistant to 8-MOP/UVA induced apoptosis. When cells were incubated for 30 minutes with 8-MOP prior to UVA exposure, higher percentages of annexin V positive cells were detected on day 1 and day 2 after treatment. Removal of 8-MOP after UVA exposure caused no significant changes in the apoptosis kinetics during the 72 h culture period compared with unwashed cells. The results of our in vitro study indicate that it could be possible to adjust the apoptosis kinetics via modulation of the 8-MOP incubation time. In further in vivo studies it should be elucidated to which extent different apoptosis kinetics influence the therapeutic effect of ECP since steady-state apoptosis levels are probably important for establishing a long lasting immune tolerance. Furthermore we found that Tregs, according to their well-known tolerogenic function, are more resistant to apoptosis after 8-MOP/UVA treatment compared to GvHD inducing T cell populations.

Extracorporeal photopheresis for GVHD prophylaxis after reduced intensity conditioning allogeneic hematopoietic stem cell transplantation: a prospective multicenter phase 2 study

We performed a prospective multicenter phase 2 study to evaluate the safety and efficacy of prophylactic Extracorporeal Photopheresis (ECP) in adult patients with hematological malignancies early after RIC allo-HSCT on day 21 twice per week during the first two weeks and then once per week for the next four weeks for a total of eight ECP courses. A total of 20 patients were included; 10 were males, median age was 60 years. All patients engrafted, 17 (85%) received the total eight ECP courses. There were no adverse effects related to ECP. Seven patients developed acute graft-versus-host disease (GVHD), with 15% grade ≥ II cumulative incidence at day 100. The cumulative incidence of chronic GVHD at 2 years was 22%. The 2 years probability of overall survival (OS) and progression-free survival (PFS) were 84 and 74%, respectively. This study shows encouraging results with low acute and chronic GVHD incidence and no interference with graft-versus-leukemia (GVL) effect.

Extracorporeal photopheresis: Review of technical aspects

Extracorporeal photochemotherapy (ECP) is considered as an immune modulating therapy majorly targeting the T cells of the Immune system. ECP induces an anti-inflammatory condition with tolerogenic responses without inducing a global immunosuppression state which is a typical feature of other therapeutic options such as steroids. Clinical indication of ECP has grown over time since its initial applications. Our review discusses the technical aspects of the concept of photopheresis with the available methods for its clinical applications.

The effect of extracorporeal photopheresis on T cell response in chronic graft-versus-host disease

Extracorporeal photopheresis (ECP) is a safe and effective immunoregulatory therapy for steroid-refractory chronic graft-versus-host disease (cGVHD) but its mechanism of action is poorly understood. In this study, we evaluated the effect of ECP in a sample of cGVHD patients. Our data showed that ECP-treated patients had lower CD4 T and B cells, and substantially higher NK cells than untreated patients. T regulatory (Treg) cells were similar between the two groups of patients. Interestingly, Treg cells were higher in ECP-treated patients and ECP-responders who had no history of aGVHD or sclerosis, than in those who had one of them or both. These findings suggest that at least one of the mechanisms of immunomodulation by ECP targets the Treg cell population and that an increase in Treg cells may be associated with response in patients with cGVHD. Together, the results of ECP are different depending on the patients' clinical condition.

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

National Institutes of Health State of the Science Symposium in Therapeutic Apheresis: scientific opportunities in extracorporeal photopheresis

The clinical use of extracorporeal photopheresis (ECP) for accepted indications such as graft-versus-host disease, transplant rejection, and cutaneous T-cell lymphoma continues to increase. Expanded applications for ECP, such as the treatment of select autoimmune diseases, are being explored. Extracorporeal photopheresis's capacity to both immunotolerize in the autoreactive setting, while immunizing against a lymphoma is unusual and suggestive of a unique mechanism. It is likely that ECP's induction of dendritic cells is key to its efficacy in both of these settings, but exactly how ECP impacts other immune components and their interactions is not fully understood. Further basic science research is necessary to elucidate how these dissimilar cellular activities are functionally integrated. On the clinical side, collaborative multicenter trials designed to recognize the principal variables controlling therapeutic responses and improve prognostic indicators may enable tailoring devices, treatment schedules, and doses to the needs of the individual patients or diseases. This review describes our current understanding of how ECP influences the immune system, reviews the existing clinical applications of ECP, and explores areas for future basic science and clinical research as presented at the National Institutes of Health State of the Science Symposium in Therapeutic Apheresis in November 2012.

Extracorporeal photopheresis combined with pentostatin in the conditioning regimen for canine hematopoietic cell transplantation does not prevent GVHD

Extracorporeal photopheresis (ECP) and the purine analog pentostatin exert potent immunomodulatory effects. We evaluated the use of these treatment modalities to prevent GVHD in a canine model of unrelated dog leukocyte Ag-mismatched hematopoietic cell transplantation, after conditioning with 920 cGy TBI. We have shown previously in this model that 36/40 dogs given MTX alone as postgrafting immunosuppression engrafted and that 25 of 40 dogs had severe GVHD and median survival of 21 days. In the current study, nine dogs received conditioning with 920 cGy TBI and postgrafting MTX either with ECP on days -2 to -1 alone (n=5) or ECP on days -6 and -5 combined with two doses of pentostatin (days -4 to -3) (n=4). Seven of nine dogs achieved engraftment. Six dogs developed severe acute GVHD (four in the group with ECP alone and two with pentostatin and ECP). We failed to demonstrate a positive impact of ECP and pentostatin for the prevention of GVHD compared with historical control dogs.

Modulation of lymphocyte subpopulations by extracorporeal photopheresis in patients with acute graft-versus-host disease or graft rejection

Extracorporeal photopheresis (ECP) constitutes a promising treatment for patients with steroid-refractory acute graft-versus-host disease (aGvHD) after allogeneic stem cell transplantation and for patients with graft rejection after solid organ transplantation (SOT). There is an increasing body of evidence that modulation of lymphocyte subsets might play a crucial role in the mechanism of action in ECP. We therefore analyzed immunological effects concomitantly with clinical findings in patients under ECP therapy using multicolor flow cytometry. In a patient with steroid-refractory aGvHD and a patient with progressive bronchiolitis obliterans syndrome (BOS) after double-lung transplantation, clinical responses to ECP therapy were paralleled by an increase of CD4 + CD25hiFoxP3 + regulatory T cells and a decrease of T(EMRA) (CD3 + CD8+ CD45RA+ CD62L+ effector memory T) cells as well as of natural killer (NK)T cells. In summary, immunomonitoring of T cell subsets can elucidate the mechanism of action in ECP.

Integrin-driven monocyte to dendritic cell conversion in modified extracorporeal photochemotherapy

Due to clinical efficacy and safety profile, extracorporeal photochemotherapy (ECP) is a commonly used cell treatment for patients with cutaneous T cell lymphoma (CTCL) and graft-versus-host disease (GVHD). The capacity of ECP to induce dendritic antigen-presenting cell (DC)-mediated selective immunization or immunosuppression suggests a novel mechanism involving pivotal cell signalling processes that have yet to be clearly identified as related to this procedure. In this study we employ two model systems of ECP to dissect the role of integrin signalling and adsorbed plasma proteins in monocyte-to-DC differentiation. We demonstrate that monocytes that were passed through protein-modified ECP plates adhered transiently to plasma proteins, including fibronectin, adsorbed to the plastic ECP plate and activated signalling pathways that initiate monocyte-to-DC conversion. Plasma protein adsorption facilitated 54·2 ± 4·7% differentiation, while fibronectin supported 29·8 ± 7·2% differentiation, as detected by DC phenotypic expression of membrane CD80 and CD86, as well as CD36, human leucocyte antigen D-related (HLA-DR) and cytoplasmic CD83. Further, we demonstrate the ability of fibronectin and other plasma proteins to act through cell adhesion via the ubiquitous arginine-glycine-aspartic (RGD) motif to drive monocyte-to-DC differentiation, with high-density RGD substrates supporting 54·1 ± 5·8% differentiation via αVβ3 and α5β1integrin signalling. Our results demonstrate that plasma protein binding integrins and plasma proteins operate through specific binding domains to induce monocyte-to-DC differentiation in ECP, providing a mechanism that can be harnessed to enhance ECP efficacy.

Lung transplantation for bronchiolitis obliterans after allogeneic hematopoietic stem cell transplantation

Bronchiolitis obliterans (BO) is a late onset complication of allogeneic hematopoietic stem cell transplantation (HSCT), and treatment outcome is dismal if it does not respond to immunosuppressive therapy. A 21-year-old male diagnosed with acute myeloid leukemia received an allogeneic HSCT from human leukocyte antigen- identical sibling donor. Twenty one months after transplantation, he developed progressive dyspnea and was diagnosed BO. Despite standard immunosuppressive therapy, the patient rapidly progressed to respiratory failure and Novalung® interventional lung-assist membrane ventilator was applied in the intensive care unit. Three months after the diagnosis of BO, the patient underwent bilateral lung transplantation (LT) and was eventually able to wean from the ventilator and the Novalung®. Since the LT, the patient has been under a strict rehabilitation program in order to overcome a severe lower extremity weakness and muscle atrophy. Histologic findings of the explanted lungs confirmed the diagnosis of BO. Nine months after the LT, the patient showed no signs of rejection or infectious complications, but still required rehabilitation treatment. This is the first LT performed in a patient with BO after allogeneic HSCT in Korea. LT can be an effective therapy in terms of survival for patients with respiratory failure secondary to development of BO following HSCT.

Extracorporeal photopheresis, a therapeutic option for cutaneous T-cell lymphoma and immunological diseases: state of the art

INTRODUCTION

Extracorporeal photopheresis (ECP) has been extensively used for the treatment of immune-mediated diseases for over 20 years and has a consistent and predictable safety profile with long-term use. Documenting the efficacy of ECP as therapeutic treatment has long been a matter of importance for physicians.

AREAS COVERED

The authors reviewed publications in this field with the goal of providing an overview of this therapeutic approach.

EXPERT OPINION

ECP is efficacious in a high percentage of those cutaneous T-cell lymphoma patients who have circulating malignant T cells in the context of a still-near-normal immune competence. From the side of graft-versus-host disease (GVHD), the use of ECP showed a clinical benefit in patients with steroid-refractory acute GVHD (aGVHD) and it is believed that ECP deserves to be evaluated as part of a combination strategy in first-line therapy of aGVHD. In chronic GHVD, the published data show that ECP can be effective in extensive and long-standing disease even when treatment is initiated at an advanced stage after conventional immunosuppressive and corticosteroid therapy has failed. ECP should be considered most beneficial for patients with predominantly mucocutaneous chronic GVHD. The fields of application of the procedure could be vast, and could also include autoimmune and metabolic diseases. The most important methodological issues which affect ECP evaluation is that the large majority of data about ECP result from single-arm observational series and the significant efficacy is mainly based on small and retrospective studies. ECP has never been proved to offer any survival advantage in a context of a randomized trial and the above-mentioned limitation also affects the accuracy of many biological modifications observed during ECP. Starting from these considerations, the need of a prospective randomized study becomes increasingly urgent.

Treatment of chronic graft-versus-host disease: Past, present and future

Chronic GVHD was recognized as a complication of allogeneic hematopoietic cell transplantation more than 30 years ago, but progress has been slowed by the limited insight into the pathogenesis of the disease and the mechanisms that lead to development of immunological tolerance. Only 6 randomized phase III treatment studies have been reported. Results of retrospective studies and prospective phase II clinical trials suggested overall benefit from treatment with mycophenolate mofetil or thalidomide, but these results were not substantiated by phase III studies of initial systemic treatment for chronic GVHD. A comprehensive review of published reports showed numerous deficiencies in studies of secondary treatment for chronic GVHD. Fewer than 10% of reports documented an effort to minimize patient selection bias, used a consistent treatment regimen, or tested a formal statistical hypothesis that was based on a contemporaneous or historical benchmark. In order to enable valid comparison of the results from different studies, eligibility criteria, definitions of individual organ and overall response, and time of assessment should be standardized. Improved treatments are more likely to emerge if reviewers and journal editors hold authors to higher standards in evaluating manuscripts for publication.

The spectrum of noninfectious pulmonary complications following hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is an established treatment for a variety of malignant and nonmalignant conditions. Pulmonary complications, infectious and noninfectious, are a major cause of morbidity and mortality in these patients. The recent advances in prophylaxis and treatment of infectious complications increased the significance of noninfectious pulmonary conditions. Acute lung injury due to diffuse alveolar hemorrhage or idiopathic pneumonia syndrome are the main acute complications, while bronchiolitis obliterans remains the most challenging pulmonary complications facing clinicians who are taking care of HSCT recipients. There are other noninfectious pulmonary complications following HSCT that are less frequent. This report provides a clinical update of the incidence, risk factors, pathogenesis, clinical characteristics and management of the main noninfectious pulmonary complications following HSCT.

Receiver operating characteristic curve analysis of circulating blood dendritic cell precursors and T cells predicts response to extracorporeal photopheresis in patients with chronic graft-versus-host disease

BACKGROUND

One proposed mechanism of extracorporeal photopheresis (ECP) in reducing chronic graft-versus-host disease (cGVHD) is alteration in numbers of circulating dendritic cells (DCs). This hypothesis was tested by correlating numbers of DC precursors and T cells in the blood before and during ECP therapy with response of cGVHD.

STUDY DESIGN AND METHODS

Twenty-five patients with cGVHD were treated with ECP. Data were collected with emphasis on blood cellular markers, clinical response to ECP, and overall survival.

RESULTS

Fourteen patients (56%) responded and had better 2-year survival than nonresponders (88% vs. 18%, p=0.003). Responders had higher baseline circulating myeloid DC (mDC) and plasmacytoid DC precursors and CD4+ and CD8+ T cells compared with nonresponders. Receiver operating characteristic curve analyses showed that the best baseline cutoff values to predict response to ECP were mDC counts of 3.7 cells/µL (79% sensitivity, 82% specificity) and CD4+ T-cell counts of 104 cells/µL (71% sensitivity, 82% specificity). CD4+ T cells declined in responders over time, but not in nonresponders, and no significant changes were seen in CD8 T-cell or DC numbers over a 12-month period in responder or nonresponder groups.

CONCLUSIONS

Higher baseline numbers of circulating DCs and T cells may predict clinical response to ECP in patients with cGVHD.

Extracorporeal photopheresis in addition to pentostatin in conditioning for canine hematopoietic cell transplantation: role in engraftment

Extracorporeal photopheresis (ECP) and the purine analog pentostatin exert potent immunomodulatory effects, but have not been evaluated for their ability to enhance engraftment of hematopoietic stem cells. We evaluated, in a canine model of dog leukocyte antigen (DLA)-identical hematopoietic cell transplantation (HCT), whether ECP in combination with pentostatin could enhance engraftment using a nonmyeloablative regimen consisting of 100 cGy TBI and postgrafting immunosuppression with mycophenolate mofetil and CYA. We have shown previously that with 100 cGy TBI alone as conditioning, all of the six dogs rejected their grafts 2-12 weeks after HCT. With the addition of pentostatin to 100 cGy TBI, 6 of 10 dogs rejected their graft. We now tested the additional use of ECP alone (n=2) or ECP and 3-6 doses of pentostatin (n=7) before 100 cGy TBI and HCT. Eight out of nine dogs rejected their grafts within 6-11 weeks after HCT. Compared with data without ECP, we failed to demonstrate a positive impact of the use of either ECP or pentostatin for prevention of rejection.

Extracorporeal photopheresis for the prevention of acute GVHD in patients undergoing standard myeloablative conditioning and allogeneic hematopoietic stem cell transplantation

GVHD is partly mediated by host APCs that activate donor T cells. Extracorporeal photopheresis (ECP) can modulate APC function and benefit some patients with GVHD. We report the results of a study using ECP administered before a standard myeloablative preparative regimen intended to prevent GVHD. Grades II-IV acute GVHD developed in 9 (30%) of 30 recipients of HLA-matched related transplants and 13 (41%) of 32 recipients of HLA-matched unrelated or HLA-mismatched related donor transplants. Actuarial estimates of overall survival (OS) at day 100 and 1-year post transplant were 89% (95% CI, 78-94%) and 77% (95% CI, 64-86%), respectively. There were no unexpected adverse effects of ECP. Historical controls receiving similar conditioning and GVHD prophylaxis regimens but no ECP were identified from the database of the Center for International Blood and Marrow Transplant Research and multivariate analysis indicated a lower risk of grades II-IV acute GVHD in patients receiving ECP (P=0.04). Adjusted OS at 1 year was 83% in the ECP study group and 67% in the historical control group (relative risk 0.44; 95% CI, 0.24-0.80) (P=0.007). These preliminary data may indicate a potential survival advantage with ECP for transplant recipients undergoing standard myeloablative hematopoietic cell transplantation.

Extracorporeal photo-apheresis for the treatment of steroid-resistant graft versus host disease

Acute and chronic graft versus host disease are frequent and potentially severe complications of allogeneic hematopoietic stem cell transplantation and are among the leading causes of non-relapse transplant-related mortality. For patients with steroid refractory disease, prognosis is particularly poor and although a variety of treatment options are available, responses are commonly transient and the side effects often intolerable. Since it was first introduced for the treatment of cutaneous T-cell lymphoma, extracorporeal photo-apheresis has been utilized as an immunomodulatory therapy for certain autoimmune diseases and solid organ transplant rejection. Recently, extracorporeal photo-apheresis has become a promising alternative for patients with graft versus host disease with disabling or potentially lethal complications. Here we review the experience of extracorporeal photo-apheresis for the treatment of steroid refractory acute and chronic graft versus host disease based on the current literature.