Extracorporeal photopheresis-induced immune tolerance: a focus on modulation of antigen-presenting cells and induction of regulatory T cells by apoptotic cells

Extracorporeal Photopheresis Enhances the Frequency and Function of Highly Suppressive FoxP3 + Treg Subsets in Heart Transplanted Individuals

BACKGROUND

Extracorporeal photopheresis (ECP) has emerged as a prophylactic and therapeutic immunomodulatory option for managing acute rejection in heart transplants (HTx). The underlying mechanisms through which ECP exerts its immunomodulatory effects remain under investigation. Regulatory T cells (Treg) are a heterogeneous subset of immune lymphocytes that ensure the maintenance of tissue homeostasis, avoiding graft rejection. The transcription factor forkhead box protein 3 (FoxP3) is an essential molecular marker of Treg, acting as a "master regulator" of their genesis, stability, and functions. No study has investigated whether ECP impacts FoxP3 expression and its highly suppressive variants containing the exon 2 (FoxP3-E2), particularly in HTx.

METHODS

In the current study, we recruited 14 HTx participants who had undergone ECP therapy. We explored the effect of in vivo ECP on CD4 + FoxP3 + Treg frequency and in vitro suppressive function in 8 HTx participants before (T0) and after 3 (T1), 6 (T2), and 12 (T3) mo of treatment. As a control group, we included 4 HTx individuals who had not undergone ECP therapy.

RESULTS

We found that ECP increases the frequency of CD4 + FoxP3 + Treg subset with highly suppressive phenotype, including CD4 + FoxP3-E2 + Treg. At functional levels, we observed that ECP treatment in HTx individuals effectively improves Treg suppressive ability in controlling the proliferation of autologous conventional CD4 + T lymphocytes.

CONCLUSIONS

Our findings collectively suggest that ECP exerts its immunomodulatory effects in HTx individuals by positively impacting the frequency and regulatory function of the FoxP3 + Treg compartment.

Extracorporeal photopheresis for the prevention of rejection after lung transplantation: a prospective randomised controlled trial

BACKGROUND

Lung transplant recipients have the worst long-term outcomes of all solid organs due to acute rejection and chronic lung allograft dysfunction (CLAD). Our objective was to investigate the efficacy of extracorporeal photopheresis (ECP) as a prophylactic treatment to prevent acute cellular rejection (ACR), cytomegalovirus (CMV) infections and reduce the risk of CLAD.

METHODS

This was a single-centre prospective randomised controlled trial conducted at the Medical University of Vienna (Vienna, Austria) between 2018 and 2020. It included 31 COPD recipients per group. The treatment group underwent ECP in addition to a standard triple-drug immunosuppression protocol after lung transplantation. The control group received standard triple-drug immunosuppressive therapy. The primary outcome was a composite outcome defined as incidence of high-grade ACR, CMV infection or CLAD within 24 months after lung transplantation.

RESULTS

In the control group, 19 patients (61.3%) achieved the primary combined end-point compared with only six patients (19.4%) in the treatment group (p<0.001). Freedom from high-grade ACR was significantly greater in the ECP group (p=0.045). Cumulative A scores were significantly lower in the ECP group than in the control group at 3 months (0.18±0.44 versus 0.56±0.94; p<0.05) and at 12 months (0.25±0.48 versus 1.0±1.45; p=0.002). The rate of infections was lower in the ECP group with five cases and 67 cumulative hospital days compared with 22 cases and 309 days in the control group (p=0.002). Freedom from CLAD at 3 years was significantly greater in the ECP group (p=0.015).

CONCLUSION

Adding ECP to standard triple immunosuppression resulted in a significant reduction of the number of ACR episodes and significantly lower incidence of CLAD.

Management of Busulfan-Induced Lung Injury in Pediatric Patients with High-Risk Neuroblastoma

Background/Objectives: Integrating the cytotoxic drug busulfan into a high-dose chemotherapy regimen prior to autologous hematopoietic stem cell rescue in patients with high-risk neuroblastoma has improved the survival of children battling this deadly disease. Busulfan-induced toxicities can, however, be severe. Here, we describe the diagnosis and successful treatment of acute pulmonary injury by total-body-weight-adjusted busulfan therapy in two children with high-risk neuroblastoma. Case series: Patient 1 developed life-threatening biphasic acute respiratory failure on days +60 and +100 after busulfan therapy, requiring intubation and invasive mechanical ventilation. Despite intensive anti-inflammatory and immunomodulatory therapy, including systemic corticosteroids, topical inhalation regimens, azithromycin, nintedanib and extracorporal photopheresis, patient 1 required extended intensive care measures and non-invasive respiratory support for a total of 20 months. High-resolution computed tomography showed diffuse intra-alveolar and interstitial patterns. Patient 2 developed partial respiratory failure with insufficient oxygen saturation and dyspnea on day +52 after busulfan therapy. Symptoms were resolved after 6 months of systemic corticosteroids, topical inhalation regimens and azithromycin. High-resolution computed tomography showed atypical pneumonic changes with ground-glass opacities. While both patients fully recovered without evidence of pulmonary fibrosis, cancer therapy had to be paused and then modified until full recovery from busulfan-induced lung injury. Conclusions: Busulfan-induced lung injury requires prompt diagnosis and intervention. Symptoms and signs are nonspecific and difficult to differentiate from other causes. Therapeutic busulfan drug level monitoring and the identification of patients at risk for drug overdosing through promoter polymorphisms in the glutathione S-transferase alpha 1 gene encoding the main enzyme in busulfan metabolism are expected to reduce the risk of busulfan-induced toxicities.

Safety and Efficacy of Extracorporeal Photopheresis for Acute and Chronic Graft-versus-Host Disease

Background/Objectives: Despite novel biological agents, steroid-dependent or -refractory graft-versus-host disease (GvHD) remains a severe complication of allogeneic hematopoietic cell transplantation (allo-HCT). Extracorporeal photopheresis (ECP) is an alternative, non-immunosuppressive treatment for patients with acute (aGvHD) or chronic (cGvHD) GvHD. The aim of this study was to investigate the safety and efficacy of ECP in the treatment of acute and chronic GvHD; Methods: We prospectively studied 112 patients with cGvHD who received one or more previous lines of treatment and 28 patients with steroid-dependent or refractory grade II-IV aGvHD post-alloHSCT. Results: In terms of severe aGvHD, most of the patients (19/28) responded to ECP treatment, while the five-year overall survival (OS) was 34%. After adjustment for several confounder factors, the reduction in immunosuppression (p = 0.026) and number of ECP sessions (p < 0.001) were associated with improved OS. Regarding chronic GvHD, only 19 patients failed to respond to ECP treatment; though significantly lower rates of response were presented in patients with visceral involvement (p = 0.037) and earlier post-transplant GVHD diagnosis (p = 0.001). Over a follow-up period of 45.2 [interquartile range (IQR): 5.6-345.1] months, the 5-year cumulative incidence (CI) of cGvHD-related mortality was 21.2% and was significantly reduced in patients with ECP response (p < 0.001), while the 5-year OS was 65.3%. Conclusions: Our results confirm the safety and efficacy of ECP in patients with GvHD and provide sufficient data for further investigation and the best combination drugs needed such that GvHD will not be the major barrier of allo-HCT in the near future.

Mode of action, indications and recommendations on extracorporeal photopheresis (ECP)

Extracorporeal photopheresis (ECP) has gained importance in the treatment of several diseases. Initially introduced as a new therapeutic modality for the treatment of patients with cutaneous T-cell lymphoma, the indications for the use of ECP have expanded to include hematology and transplantation immunology. Extracorporeal photopheresis has found its place in the treatment plan of cutaneous T-cell lymphoma, systemic sclerosis, graft-versus-host disease, organ transplantation such as heart and lung, sometimes as first-line therapy and very often in combination with various systemic immunosuppressive therapies. The procedure basically consists of three steps: leukapheresis, photoactivation and reinfusion. The following article presents possible theories about the mechanism of action, which is not yet fully understood, and discusses the five most common indications for ECP treatment with corresponding therapy recommendations.

Single centre retrospective analysis of extracorporeal photopheresis (ECP) therapy in patients heavily pre-treated for chronic graft-versus-host disease (cGvHD) with steroid failure

BACKGROUND

Extracorporeal photopheresis (ECP) is recommended as a second- or later-line therapy for chronic GvHD (cGvHD). Benefits include reasonable response with avoidance of intense systemic immunosuppression, which can translate into lowering the risk of systemic toxicity and opportunistic infection.

METHODS

We evaluated 75 patients treated with ECP for cGvHD from 2007 to 2021 at Princess Margaret Cancer Centre, and analyzed overall response rate (ORR) and clinical benefit (CB) at 3, 6 and 12 months plus other long-term treatment outcomes.

RESULTS

With a median follow-up of 72 months, a gradual increase in ORR was noted over time: 21% (16 out of 75 patients), 57% (36/63) and 70% (32/46) at month 3, 6 and 12, respectively. Gradual increase in CB was also observed over time with CB rate of 23% (17/75), 62% (39/63), and 76% (35/46) at months 3, 6 and 12, respectively. A total of 27 failures (36%) were noted, due to: 1) ECP resistance requiring switch to other therapy (n = 14, 19%), 2) non-relapse mortality (n = 10, 13%), 3) relapse of primary disease (n = 1, 1%) or 4) ECP procedure-related complication (n = 1, 1%, line infection), with 20 deaths (27%) observed. Failure-free survival (FFS) and overall survival (OS) rates were 68.3% and 85.9% at 12 months, respectively. After starting ECP, the proportions of patients who completely discontinued steroids were 17%, 32%, and 64% at months 3, 6 and 12, respectively.

CONCLUSION

ECP is an effective treatment option for heavily pre-treated cGvHD patients.

Wirkweise, Indikationen und Therapieempfehlungen der extrakorporalen Photopherese (ECP)

Die extrakorporale Photopherese (ECP) hat in jüngster Zeit bei der Behandlung verschiedener Krankheiten an Bedeutung gewonnen. Ursprünglich als neue Therapie zur Behandlung von Patienten mit kutanem T‐Zell‐Lymphom vorgestellt, hat sich der Indikationsbereich für die ECP auf Hämatologie und Transplantationsimmunologie erweitert. Die ECP hat ihren festen Platz im Therapieplan bei kutanen T‐Zell‐Lymphomen, systemischer Sklerose, Graft‐versus‐Host‐Erkrankung, Organtransplantationen wie Herz und Lunge, teilweise als Erstlinientherapie und sehr häufig in Kombination mit verschiedenen systemischen immunsuppressiven Therapien. Das Verfahren besteht im Wesentlichen aus drei Schritten: Leukapherese, Photoaktivierung und Reinfusion. Im folgenden Artikel werden die noch nicht vollständig verstandenen Wirkmechanismen dargestellt, die fünf häufigsten Indikationen für die Behandlung mit ECP diskutiert und Therapieempfehlungen für die jeweilige Indikation gegeben.

Extracorporeal photopheresis and the cellular mechanisms: Effects of 8-methoxypsoralen and UVA treatment on red blood cells, platelets and reactive oxygen species

BACKGROUND AND OBJECTIVES

Extracorporeal photopheresis (ECP) is a widespread cellular therapy for graft-versus-host disease, autoimmune diseases and Sézary disease. One of the main effects of ECP is the apoptosis of leukocytes, but the therapeutic mechanisms are not completely known. The aim of this study was to investigate the effects on red blood cells, platelets and the induction of reactive oxygen species.

MATERIALS AND METHODS

We used human cells from healthy blood donors to simulate in vitro the composition in an apheresis bag. Cells were treated with 8-methoxypsoralen (8-MOP) and UVA. Red blood cell stability, platelet activity and induction of reactive oxygen species were analysed.

RESULTS

After 8-MOP and UVA treatment, the red blood cells showed high cell integrity with low levels of eryptosis and no increase of free haemoglobin or red blood cell distribution width (RDW). Red blood cell immune-associated antigens CD59 and CD147 were hardly affected by the treatment. Platelet glycoproteins CD41, CD62P and CD63 indicated strong platelet activation after 8-MOP and UVA treatment. Reactive oxygen species were slightly but not significantly induced by the treatment.

CONCLUSION

The effect of the ECP therapy is probably not exclusively mediated by leukocytes. Platelet activation is another striking effect caused by the treatment of the apheresis product with 8-MOP/UVA. However, since we could hardly identify any evidence for eryptosis or haemolysis, it is unlikely that red blood cell eryptosis is part of the therapeutic mechanism. Further research on this topic seems to be promising.

Validation of a new automated irradiation system for off-line ECP

Extracorporeal photopheresis (ECP) is a cell therapy originally employed for cutaneous T cell lymphoma and later for GvHD, solid organ rejection and other immunological diseases demonstrating an excellent safety profile. Mononuclear cell (MNCs) apoptosis triggered by UV-A light irradiation in the presence of 8-methoxypsoralene has a key role in priming the cells, ultimately leading to immunomodulation. We report preliminary data about an evaluation of the new automated irradiator device LUMILIGHT (Pelham Crescent srl) for off-line ECP. Fifteen MNCs samples collected by apheresis from 15 adult patients undergoing ECP at our Center were cultured immediately after irradiation along with untreated samples and evaluated at 24, 48 and 72 h timepoints for T cell apoptosis and viability by flow cytometry with Annexin V and Propide Iodidum staining. Post irradiation Hematocrit (HCT), calculated by the device, was compared with that of the automated cell counter. Bacterial contamination was also tested. In irradiated samples after 24-48 and 72 h, the average total apoptosis was 47 %, 70 % and 82 %, respectively, showing a significant difference from untreated samples; residual viable lymphocytes at 72 h were, on average, 18 %. The greatest initiation of apoptosis occurred from 48 h of irradiation onwards. Average early apoptosis of irradiated samples decreased over time (26 %, 17 % and 10 % at 24, 48 and 72 h, respectively). HCT measured by LUMILIGHT was over-estimated, possibly due to the low pre irradiation red blood cell contamination. Bacterial tests resulted negative. Our study showed the LUMILIGHT device to be a valid instrument for MNCs irradiation with good handling and no major technical problems as well as no adverse events in the patients. Our data need to be confirmed in larger studies.

Effects of Extracorporeal Photopheresis on Quality of Life and the Course of Diseases in Patients With Mycosis Fungoides and Graft-Versus-Host Disease: A Single-Center Analysis

INTRODUCTION

The aim of the study was to systematically analyze the influence of extracorporeal photopheresis (ECP) on the quality of life (LQ) and the course of the disease in patients with Mycosis Fungoides (MF), as well as with Graft-versus-Host Disease (GvHD).

METHODS

LQ was monitored retrospectively by using the dermatology life quality index (DLQI) and Skindex-29 test before ECP onset and after the last ECP. Disease parameters were assessed by objective criteria i.e. number of associated medical drugs taken, intervals between therapeutic cycles, gradual change of the disease, and eventual side-effects and complications of ECP therapy.

RESULTS

Fifty-one patients were treated with ECP during 2008-19; 19 out of 51 died, and follow-up was not completed in 13 patients. Finally, treatment protocols of 671 ECP procedures were evaluated in 19 patients (10 MF; 9 GvHD). MF and GvHD subpopulations did not differ in the individual scores of LQ questions, either before the outset or after the last ECP. DLQI and Skindex-29 scores were ameliorated by the ECP therapy (p= 0.001 and p< 0.001, respectively) due to improvement of individual scores of feelings, daily/social activities (p< 0.05), and functionality (p≤ 0.05). The median interval between ECP cycles was extended from two to eight weeks (p= 0.001). Needs of GvHD patients for drugs being received for the underlying disease were reduced (p= 0.035). Two of the 10 MF patients worsened from stage IIA to IIIA. Severe or minor side effects leading to a therapy interruption were not recorded.

CONCLUSION

Patients with GvHD experienced a notable decrease in the administration of drugs for their underlying condition, and there were no instances of severe side effects that resulted in the discontinuation of treatment. ECP is safe and effective for the treatment of MF and GvHD.

Extracorporeal photopheresis versus standard treatment for acute graft-versus-host disease after haematopoietic stem cell transplantation in children and adolescents

BACKGROUND

Acute graft-versus-host disease (aGvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation (HSCT), occurring in 8% to 85% of paediatric recipients. Currently, the therapeutic mainstay for aGvHD is treatment with corticosteroids. However, there is no established standard treatment for steroid-refractory aGvHD. Extracorporeal photopheresis (ECP) is a type of immunomodulatory method amongst different therapeutic options that involves ex vivo collection of peripheral mononuclear cells, exposure to the photoactive agent 8-methoxypsoralen and ultraviolet-A radiation, and reinfusion of these treated blood cells to the patient. The mechanisms of action of ECP are not completely understood. This is the second update of a Cochrane Review first published in 2014 and updated in 2015.

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of aGvHD in children and adolescents after HSCT.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE (PubMed) and Embase (Ovid) databases from their inception to 25 January 2021. We searched the reference lists of potentially relevant studies without any language restrictions. We searched five conference proceedings and nine clinical trial registries on 9 November 2020 and 12 November 2020, respectively.

SELECTION CRITERIA

We sought to include randomised controlled trials (RCTs) comparing ECP with or without standard treatment versus standard treatment alone in children and adolescents with aGvHD after HSCT.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreement in the selection of trials by consultation with a third review author.

MAIN RESULTS

We identified no additional studies in the 2021 review update, so there are still no studies that meet the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy of ECP in the treatment of aGvHD in children and adolescents after HSCT is unknown, and its use should be restricted to within the context of RCTs. Such studies should address a comparison of ECP alone or in combination with standard treatment versus standard treatment alone. The 2021 review update brought about no additions to these conclusions.

Extracorporeal photopheresis versus alternative treatment for chronic graft-versus-host disease after haematopoietic stem cell transplantation in children and adolescents

BACKGROUND

Chronic graft-versus-host disease (cGvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation, occurring in 6% to 65% of the paediatric recipients. Currently, the therapeutic mainstay for cGvHD is treatment with corticosteroids, frequently combined with other immunosuppressive agents in people with steroid-refractory manifestations. There is no established standard treatment for steroid-refractory cGvHD. The therapeutic options for these patients include extracorporeal photopheresis (ECP), an immunomodulatory treatment that involves ex vivo collection of mononuclear cells from peripheral blood, exposure to the photoactive agent 8-methoxypsoralen, ultraviolet radiation and re-infusion of the processed cell product. The mechanisms of action of ECP are not completely understood. This is the second update of a Cochrane Review first published in 2014 and first updated in 2015.

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of cGvHD in children and adolescents after haematopoietic stem cell transplantation.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL) (2021), MEDLINE (PubMed) and Embase databases from their inception to 25 January 2021. We searched the reference lists of potentially relevant studies without any language restrictions. We searched five conference proceedings and nine clinical trial registries on 9 November 2020 and 12 November 2020, respectively.

SELECTION CRITERIA

We aimed to include randomised controlled trials (RCTs) comparing ECP with or without alternative treatment versus alternative treatment alone in children and adolescents with cGvHD after haematopoietic stem cell transplantation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreements in the selection of trials by consultation with a third review author.

MAIN RESULTS

We found no studies meeting the criteria for inclusion in this 2021 review update.

AUTHORS' CONCLUSIONS

We could not evaluate the efficacy of ECP in the treatment of cGvHD in children and adolescents after haematopoietic stem cell transplantation since the second review update again found no RCTs. Current recommendations are based on retrospective or observational studies only. Thus, ideally, ECP should be applied in the context of controlled trials only. However, performing RCTs in this population will be challenging due to the limited number of eligible participants, variable disease presentation and the lack of well-defined response criteria. International collaboration, multicentre trials and appropriate funding for such trials will be needed. If treatment decisions based on clinical data are made in favour of ECP, recipients should be carefully monitored for beneficial and harmful effects. In addition, efforts should be made to share this information with other clinicians, for example by setting up registries for children and adolescents treated with ECP.

Continuation of systemic treatments and outcomes for patients with chronic graft-versus-host disease in the USA

Aim: To compare secondary systemic treatment (SST) continuation and associated resource use and costs in chronic graft-versus-host disease (cGvHD) patients in the USA. Materials & methods: This was a retrospective study using Truven Health MarketScan database (2009-2016). cGvHD patients were classified as continuers or discontinuers if treated with SST for ≥180 days without or with a treatment gap (≥45 days), respectively. Results: Among 464 cGvHD patients with SST, mTOR inhibitors, extracorporeal photopheresis and imatinib were most frequently used. A total of 172 patients were SST continuers and 292 were discontinuers. Extracorporeal photopheresis treated patients were the highest continuers, followed by imatinib and mTOR inhibitors. SST continuers had lower monthly hospitalization costs versus discontinuers. Conclusion: This real-world analysis demonstrates high SST continuation rates in cGvHD patients are associated with lower resource utilization and cost.

An update on current treatment strategies for managing bronchiolitis obliterans syndrome after lung transplantation

INTRODUCTION

Bronchiolitis obliterans syndrome (BOS), a subtype of chronic lung allograft dysfunction, is quite common, with up to half of all lung recipients developing BOS within 5 years of transplantation. Preventive efforts are aimed at alleviating known risk factors of BOS development, while the primary goal of treatment is to delay the irreversible, fibrotic airway changes, and progressive loss of lung function.

AREAS COVERED

This narrative review will briefly discuss the updated definition, clinical presentation, pathogenesis, risk factors, and survival after BOS while paying particular attention to the salient evidence for optimal preventive strategies and treatments based on investigations in the modern era.

EXPERT OPINION

Future translational research focused on further characterizing the complex interplay between immune and nonimmune mechanisms mediating chronic lung rejection is the first step toward mitigating risk of allograft injury, improving early disease detection with noninvasive biomarkers, and ultimately, developing an effective, targeted therapy that can extend the life of the lung allograft.

Efficacy of Granulocyte and Monocyte Adsorptive Apheresis in Patients With Inflammatory Bowel Disease Showing Lost Response to Infliximab

BACKGROUND AND AIMS

In inflammatory bowel disease [IBD] patients, antibody-to-infliximab [ATI] generation is responsible for loss of response [LOR] and infusion reaction [IR] to infliximab. An immuno-therapeutic approach is considered an option to overcome LOR. Granulocyte/monocyte adsorptive apheresis [GMA] using an Adacolumn has been shown to have clinical efficacy together with immunomodulatory effects in IBD patients.

METHODS

We developed an ATI-CAI assay utilizing a C1q immobilized plate and applied it to measure ATI in patients who were receiving infliximab, including 56 with sustained response, 76 with LOR and six with IR. Furthermore, 14 patients with LOR and two with paradoxical skin reactions who received infliximab + GMA combination therapy were analysed.

RESULTS

Fourteen patients with LOR, seven with Crohn's disease and seven with ulcerative colitis, showed significantly improved clinical indices [p = 0.0009], and decreased ATI [p = 0.0171] and interleukin-6 [p = 0.0537] levels at week 8 following initiation of infliximab + GMA therapy. Nine patients who received combination therapy achieved remission, which was maintained to week 24 with infliximab alone. Additionally, cutaneous lesions in two patients with IR were improved. ATI-CAI assay efficiency was not influenced by infliximab concentration during the test. Pre- and post-infliximab infusion ATI levels were not different. Patients with ATI greater than the 0.153 μg/mL cut-off value were likely to experience LOR [odds ratio 3.0].

CONCLUSIONS

Patients who received infliximab + GMA therapy appeared to regain clinical response to infliximab by a decrease in ATI level. Furthermore, the concentration of infliximab in the test did not influence ATI measurement, but was associated with clinical response.

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.

An alternative for extracorporeal photopheresis: 8-methoxypsoralen and UVA-treated leucocytes from allogeneic donors improve graft-versus-host disease in mice

BACKGROUND AND OBJECTIVE

Extracorporeal photopheresis (ECP) is an important immune tolerance inducing therapy for graft-versus-host disease (GvHD). However, a sufficient number of ECP cycles cannot be performed in patients with severe GvHD and contraindications for apheresis. Allogeneic sources of leucocytes for use as ECP treatment would be of great benefit. Therefore, this study aimed to test the therapeutic potential of novel sources of leucocytes for ECP.

MATERIALS AND METHODS

Graft-versus-host disease mice were treated with ECP using therapeutic cells from different allogeneic sources. Splenocytes were incubated with 8-methoxypsoralen (8-MOP), irradiated with UVA light and injected into GvHD mice as a model for ECP.

RESULTS

The therapy with 8-MOP/UVA-treated cells from healthy mice of the bone marrow transplantation (BMT) donor strain reduced the GvHD symptoms, at least in a model of chronic GvHD. In the acute GvHD model, 8-MOP/UVA-treated cells from the BMT donor or recipient strain did not show significant improvements in GvHD symptoms or survival time. Pre-activation of cells by mixed lymphocyte reactions before 8-MOP/UVA treatment also failed to result in significant differences in survival time or GvHD score. In contrast, ECP with third-party 8-MOP/UVA-treated cells from a HLA-mismatched donor resulted in a mean survival time of 37 days compared to 21 days in the control group.

CONCLUSION

In our analysis of novel allogeneic leucocyte sources for ECP, we could demonstrate that the source of the 8-MOP/UVA-treated cells is crucial. The underlying immunologic effect of allogeneic 8-MOP/UVA-treated cells needs to be investigated in future studies.

4,6,4'-trimethylangelicin shows high anti-proliferative activity on DU145 cells under both UVA and blue light

OBJECTIVES

Furocoumarins (psoralens and angelicins) have been already used under ultraviolet A light (UVA) for the treatment of skin diseases and cutaneous T-cell lymphoma. Besides their high anti-proliferative activity, some severe long-term side effects have been observed, for example genotoxicity and mutagenicity, likely strictly related to the formation of crosslinks. It has been demonstrated that blue light (BL) activation of 8-methoxypsoralen, an FDA-approved drug, leads to less mutagenic monoadducts in the DNA. So far, in this work the less toxic and more penetrating BL is proposed to activate 4,6,4'-trimethylangelicin (TMA), an already known UVA photoactivatable compound.

MATERIALS AND METHODS

Photocleavage, crosslink formation and oxidative damage were detected in pBR322 plasmid DNA treated with 300.0 μmol/L TMA activated with various exposures of BL. Anti-proliferative activity, reactive oxygen species (ROS) formation and activation status of some signalling pathways involved in cell growth and apoptosis were verified on DU145 cells treated with 5.0 μmol/L TMA plus 2.0 J/cm² of BL.

RESULTS

Under BL-TMA, no mutagenic crosslinks, no photocleavage and neither photooxidative lesions were detected on isolated plasmid DNA. TMA showed high anti-proliferative activity on DU145 cells through induction of apoptosis. Besides ROS generation, the proapoptotic effect seemed to be related to activation of p38 and inhibition of p44/42 phosphorylation. Interestingly, the decrease in nuclear β-catenin was coupled with a significant dropping of CD44-positive cells.

CONCLUSION

Overall, our results indicate that TMA can be activated by BL and may be considered for targeted phototherapy of prostate cancer lesions.

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.

Treatment of Pediatric Acute Graft-versus-Host Disease-Lessons from Primary Immunodeficiency?

Allogeneic hematopoietic stem cell transplant (HSCT) is used to treat increasing numbers of malignant and non-malignant disorders. Despite significant advances in improved human leukocyte antigens-typing techniques, less toxic conditioning regimens and better supportive care, resulting in improved clinical outcomes, acute graft-versus-host disease (aGvHD) continues to be a major obstacle and, although it principally involves the skin, gastrointestinal tract, and liver, the thymus is also a primary target. An important aim following HSCT is to achieve complete and durable immunoreconstitution with a diverse T-cell receptor (TCR) repertoire to recognize a broad range of pathogens providing adequate long-term adaptive T-lymphocyte immunity, essential to reduce the risk of infection, disease relapse, and secondary malignancies. Reconstitution of adaptive T-lymphocyte immunity is a lengthy and complex process which requires a functioning and structurally intact thymus responsible for the production of new naïve T-lymphocytes with a broad TCR repertoire. Damage to the thymic microenvironment, secondary to aGvHD and the effect of corticosteroid treatment, disturbs normal signaling required for thymocyte development, resulting in impaired T-lymphopoiesis and reduced thymic export. Primary immunodeficiencies, in which failure of central or peripheral tolerance is a major feature, because of intrinsic defects in hematopoietic stem cells leading to abnormal T-lymphocyte development, or defects in thymic stroma, can give insights into critical processes important for recovery from aGvHD. Extracorporeal photopheresis is a potential alternative therapy for aGvHD, which acts in an immunomodulatory fashion, through the generation of regulatory T-lymphocytes (Tregs), alteration of cytokine patterns and modulation of dendritic cells. Promoting normal central and peripheral immune tolerance, with selective downregulation of immune stimulation, could reduce aGvHD, and enable a reduction in other immunosuppression, facilitating thymic recovery, restoration of normal T-lymphocyte ontogeny, and complete immunoreconstitution with improved clinical outcome as the ability to fight infections improves and risk of secondary malignancy or relapse diminishes.

Extracoporeal photopheresis treatment of acute graft-versus-host disease following allogeneic haematopoietic stem cell transplantation

Acute graft-versus-host disease (aGvHD) continues to be a major obstacle to allogeneic haematopoietic stem cell transplantation. Thymic damage secondary to aGvHD along with corticosteroids and other non-selective T lymphocyte-suppressive agents used in the treatment of aGvHD concurrently impair thymopoiesis and negatively impact on immunoreconstitution of the adaptive immune compartment and ultimately adversely affect clinical outcome. Extracorporeal photopheresis (ECP) is an alternative therapeutic strategy that appears to act in an immunomodulatory fashion, potentially involving regulatory T lymphocytes and dendritic cells. By promoting immune tolerance and simultaneously avoiding systemic immunosuppression, ECP could reduce aGvHD and enable a reduction in other immunosuppression, allowing thymic recovery, restoration of normal T lymphopoiesis, and complete immunoreconstitution with improved clinical outcome. Although the safety and efficacy of ECP has been demonstrated, further randomised controlled studies are needed as well as elucidation of the underlying mechanisms responsible and the effect of ECP on thymic recovery.

Extracorporeal photopheresis versus alternative treatment for chronic graft-versus-host disease after haematopoietic stem cell transplantation in paediatric patients

BACKGROUND

Chronic graft-versus-host disease (GvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation occurring in 6% to 65% of the recipients. Currently, the therapeutic mainstay for chronic GvHD are corticosteroids that are frequently combined with other immunosuppressive agents in people with steroid-refractory manifestations. There is no established standard treatment for steroid-refractory chronic GvHD. The therapeutic options for these patients include extracorporeal photopheresis (ECP), an immunomodulatory treatment that involves ex vivo collection of mononuclear cells from peripheral blood, exposure to the photoactive agent 8-methoxypsoralen, ultraviolet radiation and re-infusion of the processed cell product. The mechanisms of action of ECP are not completely understood. This is an updated version of a Cochrane review first published in 2014.

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of chronic GvHD in children and adolescents after haematopoietic stem cell transplantation.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL) (Issue 9, 2015), MEDLINE and EMBASE databases from their inception to 23 September 2015. We searched the reference lists of potentially relevant studies without any language restriction. We searched eight trial registers and five conference proceedings on 29 September 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ECP with or without alternative treatment versus alternative treatment alone in paediatric patients with chronic GvHD after haematopoietic stem cell transplantation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreements in the selection of trials by consultation with a third review author.

MAIN RESULTS

No additional studies were identified in this 2015 review update, in total leading to no studies meeting the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy of ECP in the treatment of chronic GvHD in paediatric patients after haematopoietic stem cell transplantation based on RCTs cannot be evaluated since the original version of this review and the first review update found no RCTs. Current recommendations are based on retrospective or observational studies only. Thus, ideally, ECP should be applied in the context of controlled trials only. However, performing RCTs in this patient population will be challenging due to the limited number of patients, the variable disease presentation and the lack of well-defined response criteria. International collaboration, multicentre trials and appropriate funding for such trials will be needed. If treatment decisions based on clinical data are made in favour of ECP, patients should be carefully monitored for beneficial and harmful effects. In addition, efforts should be made to share this information with other clinicians, for example by setting up registries for paediatric patients that are treated with ECP.

Extracorporeal photopheresis versus standard treatment for acute graft-versus-host disease after haematopoietic stem cell transplantation in paediatric patients

BACKGROUND

Acute graft-versus-host disease (aGvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation (HSCT) occurring in 8% to 59% of the recipients. Currently, the therapeutic mainstay for aGvHD is corticosteroids. However, there is no established standard treatment for steroid-refractory aGvHD. Extracorporeal photopheresis (ECP) is a type of immunomodulatory method amongst different therapeutic options that involves ex vivo collection of peripheral mononuclear cells, exposure to the photoactive agent 8-methoxypsoralen and ultraviolet-A radiation, and re-infusion of these treated blood cells to the patient. The mechanisms of action of ECP are not completely understood. This is an updated version of a Cochrane review first published in 2014.

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of aGvHD in children and adolescents after HSCT.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL) (Issue 9, 2015), MEDLINE (PubMed) and EMBASE (Ovid) databases from their inception to 23 September 2015. We searched the reference lists of potentially relevant studies without any language restrictions. We searched eight trial registers and four conference proceedings on 29 September 2015.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ECP with or without standard treatment versus standard treatment alone in paediatric patients with aGvHD after HSCT.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreement in the selection of trials by consultation with a third review author.

MAIN RESULTS

We identified no additional studies in the 2015 review update, in total leading to no studies meeting the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy of ECP in the treatment of aGvHD in paediatric patients after HSCT is unknown and its use should be restricted within the context of RCTs. Such studies should address a comparison of ECP alone or in combination with standard treatment versus standard treatment alone. The 2015 review update brought about no additions to these conclusions.

Infusion of dendritic cells carrying donor lymphocytes treated with 8-methoxypsoralen and ultraviolet A light induces CD19+ IL-10+ regulatory B cells and promotes skin allograft survival

PUVA-SP DCs are immature dendritic cells (imDCs) that have taken up donor splenic lymphocytes treated with 8-methoxypsoralen and ultraviolet A light (PUVA-SPs). Phagocytosis of donor PUVA-SPs does not stimulate phenotype maturation of recipient imDCs, and infusion of PUVA-SP DCs can induce CD4(+)CD25(high)Foxp3(+) regulatory T cells (Treg). However, the regulatory effect of PUVA-SP DCs on B cells is poorly understood. In this study, we compared PUVA-SP DCs with imDCs in terms of lipopolysaccharide (LPS) responsiveness and flow cytometric analysis of interleukin (IL) 10 expression in splenic CD19(+)B cells. Our results demonstrate that PUVA-SP DCs can suppress subsequent LPS-induced DC maturation and that infusion of PUVA-SP DCs, in the absence of an immunosuppressant, significantly promotes skin allograft survival. This effect was associated with up-regulation of circulating regulatory B cells exhibiting preferential IL-10 secretion. Our results suggest that effective treatments involving infusion of PUVA-SP DCs is likely related to the modulation not only of T-cell and Treg functions but also of B-cell and regulatory B-cell (Breg) functions.

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.

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.

Modified extracorporeal photopheresis with cells from a healthy donor for acute graft-versus-host disease in a mouse model

Background

Graft-versus-host disease (GvHD) is a major challenge after hematopoietic stem cell transplantation but treatment options for patients are still limited. In many cases first-line treatment with glucocorticoids is not successful. Among second-line therapies the extracorporeal photopheresis (ECP) is frequently performed, due to induction of selective tolerance instead of general immunosuppression. However, for some patients with severe acute GvHD the leukapheresis step of the ECP procedure is physically exhausting and limits the number of ECP cycles.

Methods

We hypothesized that leukocytes from healthy cell donors could be used as a replacement for ECP leukocytes gained from the GvHD patient. For this purpose we used a well established mouse model of acute GvHD. The ECP therapy was based on cells with the genetic background of the initial donor of the stem cell transplantation. As a precondition we developed a protocol representing conventional ECP in mice equivalent to clinical used ECP setup.

Results

We could demonstrate that conventional, clinically derived ECP setup is able to alleviate acute GvHD. By using leukocytes obtained from healthy mice with the bone marrow donor’s genetic background we could not observe a statistically significant therapeutic effect.

Conclusions

Conventional human ECP setup is effective in the mouse model of severe acute GvHD. In addition we could not prove that ECP cells from healthy mice with bone marrow donor’s genetic background are as effective as ECP cells derived from GvHD mice. Based on our findings, new questions arise for further studies, in which the cellular characteristics for ECP mediated immune tolerance are a matter of investigation.

Extracorporeal photopheresis versus alternative treatment for chronic graft-versus-host disease after haematopoietic stem cell transplantation in paediatric patients

BACKGROUND

Chronic graft-versus-host disease (GvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation occurring in 6% to 65% of the recipients. Currently, the therapeutic mainstay for chronic GvHD are corticosteroids that are frequently combined with other immunosuppressive agents in people with steroid-refractory manifestations. There is no established standard treatment for steroid-refractory chronic GvHD. The therapeutic options in these people include extracorporeal photopheresis (ECP), an immunomodulatory treatment that involves ex vivo collection of mononuclear cells from peripheral blood, exposure to the photoactive agent 8-methoxypsoralen, ultraviolet radiation and re-infusion of the processed cell product. The mechanisms of action of ECP are not completely understood.

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of chronic GvHD in children and adolescents after haematopoietic stem cell transplantation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (Issue 9, 2012), MEDLINE and EMBASE databases from their inception to 12 September 2012. We searched the reference lists of potentially relevant studies without any language restriction. We searched eight trial registers and five conference proceedings. We also contacted experts in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ECP with or without alternative treatment versus alternative treatment alone in paediatric patients with chronic GvHD after haematopoietic stem cell transplantation.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreements in the selection of trials by consultation with a third review author.

MAIN RESULTS

We found no studies meeting the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy of ECP in the treatment of chronic GvHD in paediatric patients after haematopoietic stem cell transplantation based on RCTs can currently not be evaluated since we have found no such studies. Current recommendations are based on retrospective or observational studies only. Thus, ideally, ECP should be applied in the context of controlled trials only. However, performing RCTs in this patient population will be challenging due to the limited number of patients, the variable disease presentation and the lack of well-defined response criteria. International collaboration, multicentre trials and appropriate funding for such trials will be needed. If treatment decisions based on clinical grounds in favour of ECP are made, people should be carefully monitored for beneficial and harmful effects and efforts should be made to share this information with other clinicians, for example by setting up registries for paediatric patients that are treated with ECP.

Extracorporeal photopheresis versus standard treatment for acute graft-versus-host disease after haematopoietic stem cell transplantation in paediatric patients

BACKGROUND

Acute graft-versus host disease (aGvHD) is a major cause of morbidity and mortality after haematopoietic stem cell transplantation (HSCT) occurring in 8% to 59% of the recipients. Currently, the therapeutic mainstay for aGvHD is corticosteroids. However, there is no established standard treatment for steroid-refractory aGvHD. Extracorporeal photopheresis (ECP) is a type of immunomodulatory method amongst different therapeutic options that involves ex vivo collection of peripheral mononuclear cells, exposure to the photoactive agent 8-methoxypsoralen and ultraviolet-A radiation, and re-infusion of these treated blood cells to the patient. The mechanisms of action of ECP are not completely understood

OBJECTIVES

To evaluate the effectiveness and safety of ECP for the management of aGvHD in children and adolescents after HSCT.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (Issue 9, 2012), MEDLINE/PubMed and EMBASE (Ovid) databases from their inception to 12 September 2012. We searched the reference lists of potentially relevant studies without any language restriction. We searched eight trial registers and four conference proceedings. We also contacted an expert in the field to request information on unpublished study that involves ECP in aGvHD after HSCT.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing ECP with or without standard treatment versus standard treatment alone in paediatric patients with aGvHD after HSCT.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. We resolved disagreement in the selection of trials by consultation with a third review author.

MAIN RESULTS

We found no studies meeting the criteria for inclusion in this review.

AUTHORS' CONCLUSIONS

The efficacy of ECP in the treatment of aGvHD in paediatric patients after HSCT is unknown and its use should be restricted within the context of RCTs. Such studies should address a comparison of ECP alone or in combination with standard treatment versus standard treatment alone. 

Phosphatidylserine exposure on the surface of Leishmania amazonensis amastigotes modulates in vivo infection and dendritic cell function

Leishmania amazonensis parasites can cause diverse forms of leishmaniasis in humans and persistent lesions in most inbred strains of mice. In both cases, the infection is characterized by a marked immunosuppression of the host. We previously showed that amastigote forms of the parasite make use of surface-exposed phosphatidylserine (PS) molecules to infect host cells and promote alternative macrophage activation, leading to uncontrolled intracellular proliferation of the parasites. In this study, we demonstrated that treatment of infected mice with a PS-targeting monoclonal antibody ameliorated parasite loads and lesion development, which correlated with increased proliferative responses by lymphocytes. In addition, we observed an enhanced dendritic cell (DC) activation and antigen presentation in vitro. Our data imply that the recognition of PS exposed on the surface of amastigotes plays a role in down-modulating DC functions, in a matter similar to that of apoptotic cell clearance. This study provides new information regarding the mechanism of immune suppression in Leishmania infection.

Extracorporeal photopheresis for the treatment of erythrodermic cutaneous T-cell lymphoma: a single center clinical experience with long-term follow-up data and a brief overview of the literature

Extracorporeal photopheresis (ECP) is a therapeutic procedure in which leukapheresed peripheral blood mononuclear cells are exposed to ultraviolet A in the presence of the photosensitizer 8-methoxypsoralen and then reinfused. Several guidelines recommend ECP as a treatment of choice in erythrodermic primary cutaneous T-cell lymphomas (E-CTCL). However, the level of evidence is low due to the rarity of this disease and the lack of randomized controlled trials. We performed a review of the English literature, restricting our analysis to studies including erythrodermic patients and more than 10 cases. Based on these criteria, we identified 28 studies, with a total of 407 patients. The median response rate in erythrodermic patients was 63% (range 31-86%), with a complete response rate ranging between 0 and 62% (median 20%). In our experience, we treated 51 patients with E-CTCL since 1992. A clinical response was obtained in 32 of 51 patients (63%), with a 16% complete response rate. The median time for response induction was eight months (range: 1-23). The median response duration was 22.4 months (range six months to 11 years). The treatment was generally well tolerated without systemic toxicities grade III-IV. The pretreatment parameters significantly associated with a higher likelihood to obtain a clinical response were the B-score in the peripheral blood, CD4/CD8 ratio, and amount of circulating CD3+CD8+ cells. Literature data together with our personal experience clearly support the clinical activity and tolerability of ECP in patients with E-CTCL. Prospective controlled clinical trials are strongly recommended to better document the evidence.

Efficacy of photopheresis extracorporeal procedure as single treatment for severe chronic GVHD: a case report

Allogeneic hematopoietic stem cell transplantation is the only potentially curative therapeutic option for many malignant and nonmalignant hematologic disorders. Despite this, several factors unfavorably affect the outcome of this procedure and in particular chronic graft-versus-host disease (cGVHD) remains the principal cause of morbidity after allogeneic transplantation. Here we present our experience regarding a patient affected by extensive chronic GVHD (cGVHD) treated only with extracorporeal photopheresis procedure (ECP) as first line treatment. The patient, presenting an high risk myelodysplastic syndrome (MDS), underwent an allogeneic peripheral stem cells transplantation. About 2 months after transplantation she experienced a hematological and clinical relapse of MDS. After reinduction therapy with azacitidine she obtained a second complete remission. Because of the risk of relapse related to a strong immunosuppressant therapy and the previous infectious complication, we decided to start a treatment with ECP alone for cGVHD. After six procedure the patient obtained a complete resolution of all signs and symptoms of the cGVHD. This experience may support the possibility to use only an immunomodulant treatment like ECP for the cGVHD, reducing the risk of complications of prolonged immunosuppressant treatment.

Combination Phototherapy with a Histone Deacetylase Inhibitor and a Potent DNA-Binding Bibenzimidazole: Effects in Haematological Cell Lines

Current treatment for cutaneous T-cell lymphoma includes phototherapy, which involves either the use of narrowband ultraviolet B light or UVA in combination with a psoralen photosensitiser. Therapy typically involves administration of the photosensitiser followed by topical exposure to UVA. A different approach is extracorporeal photopheresis, an ex vivo strategy which is used for more advanced stages of disease. Further, histone deacetylase inhibitors are emerging as potent anticancer agents with suberoylanilide hydroxamic acid and depsipeptide, having received FDA approval for the treatment of cutaneous T-cell lymphoma. We have developed UVASens, an extremely potent, DNA minor groove-binding UVA sensitizer for potential use in phototherapy. We have previously demonstrated the extreme photopotency of UVASens in human erythroleukemic K562 cells. Here we have extended those studies by investigating the photopotency of UVASens in four haematological cell lines, namely, K562, T-cell leukaemic CEM-CCRF, P-glycoprotein overexpressing R100, and transformed B-lymphoblastoid cell lines (LCL) cells. In addition, we investigated the effects of suberoylanilide hydroxamic acid in combination with UVASens. Using γH2AX as the endpoint, our findings indicate that UVASens-induced phototoxicity in all four of the haematological cell lines. The addition of suberoylanilide hydroxamic acid augmented the photopotency of UVASens highlighting the potential clinical applicability of combination therapies.

Clinical Results of Extracorporeal Photopheresis

Extracorporeal photopheresis (ECP) is a combination of leukapheresis and photodynamic therapy in which blood is treated with photoactivable drugs which are then activated with ultraviolet light and re-infused to the patient. It has been used successfully for more than 30 years in the treatment of erythrodermic cutaneous T-cell lymphoma (CTCL) and over 20 years for chronic graft-versus-host disease (GVHD). ECP has also shown promising results in the treatment of acute GVHD and other T-cell-mediated diseases, including systemic sclerosis, treatment and prevention of solid organ rejection, and more recently Crohn's disease. The use of ECP may allow a significant reduction or even discontinuation of corticosteroids and/or other immunosuppressants, thus leading to reduced long-term morbidity and mortality and improved overall survival. ECP is a well-tolerated therapy. No significant side effects have been reported during the last 30 years. It has been shown that ECP is not associated with an increased incidence of infections, malignancies, or recurrence of underlying malignant disease, neither during short-term nor during long-term therapy.

Photosensitization by iodinated DNA minor groove binding ligands: Evaluation of DNA double-strand break induction and repair

Iodinated DNA minor groove binding bibenzimidazoles represent a unique class of UVA photosensitizer and their extreme photopotency has been previously characterized. Earlier studies have included a comparison of three isomers, referred to as ortho-, meta- and para-iodoHoechst, which differ only in the location of the iodine substituent in the phenyl ring of the bibenzimidazole. DNA breakage and clonogenic survival studies in human erythroleukemic K562 cells have highlighted the higher photo-efficiency of the ortho-isomer (subsequently designated UV(A)Sens) compared to the meta- and para-isomers. In this study, the aim was to compare the induction and repair of DNA double-strand breaks induced by the three isomers in K562 cells. Further, we examined the effects of the prototypical broad-spectrum histone deacetylase inhibitor, Trichostatin A, on ortho-iodoHoechst/UVA-induced double-strand breaks in K562 cells. Using γH2AX as a molecular marker of the DNA lesions, our findings indicate a disparity in the induction and particularly, in the repair kinetics of double-strand breaks for the three isomers. The accumulation of γH2AX foci induced by the meta- and para-isomers returned to background levels within 24 and 48 h, respectively; the number of γH2AX foci induced by ortho-iodoHoechst remained elevated even after incubation for 96 h post-irradiation. These findings provide further evidence that the extreme photopotency of ortho-iodoHoechst is due to not only to the high quantum yield of dehalogenation, but also to the severity of the DNA lesions which are not readily repaired. Finally, our findings which indicate that Trichostatin A has a remarkable potentiating effect on ortho-iodoHoechst/UVA-induced DNA lesions are encouraging, particularly in the context of cutaneous T-cell lymphoma, for which a histone deacetylase inhibitor is already approved for therapy. This finding prompts further evaluation of the potential of combination therapies.

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.

Dendritic cell apoptosis: regulation of tolerance versus immunity

Dendritic cell (DC) apoptosis is an important event that regulates the balance between tolerance and immunity through multiple pathways, and defects in DC apoptosis can trigger autoimmunity. DC apoptosis is also associated with immunosuppression and has been observed under several pathologies and infections. Recent studies indicate that apoptotic DCs can also play an active role in induction of tolerance. This review discusses the regulatory pathways of DC apoptosis, stimuli inducing DC apoptosis, and the implications of DC apoptosis in the induction of immunosuppression and/or tolerance.

Experimental extracorporeal photopheresis therapy significantly delays the development of diabetes in non-obese diabetic mice

In our previous studies, we demonstrated that infusion of apoptotic cells significantly prevented type 1 diabetes (T1D) in non-obese diabetic (NOD) mice. Extracorporeal photopheresis (ECP) is an apoptotic cell-based therapy used clinically for immune-mediated disorders. In this study, we examined the effect that intravenous delivery of apoptotic cells (ECP-treated) has in the prevention of T1D in NOD mice. We discovered that five weekly injections of ECP-treated NOD spleen cells, beginning at 8 weeks of age, significantly delayed diabetes onset. Furthermore, cell dose studies demonstrated that low dose ECP-treated spleen cells (2x10(5) cells/injection/mouse) had similar protective effects as compared to high dose (5x10(6) cells/injection). In contrast to ECP-treated cells alone, ECP-treated cells combined with beta cell antigens appeared to improve the protective effect as shown by the marked reduction in insulitis in the islets. Delivery of ECP-treated spleen cells or ECP-treated spleen cells plus beta cell antigen increased Foxp3(+) Tregs, and beta cell antigen-specific T cell proliferation was significantly suppressed in vivo in these two groups. In addition, we found that ECP-treated cells did not induce global immunosuppression or autoimmunity against nuclear antigens. In conclusion, ECP-treated cells provide a safe and effective approach in T1D prevention, suggesting that clinical ECP has great potential for managing human T1D.