Shedding light on photopheresis

Infusion of Lymphocytes Treated With 8-Methoxypsoralen and Ultraviolet A Light Induces CD19+IL-10+ Regulatory B Cells and Promotes Skin Allograft Survival

Extracorporeal photopheresis (ECP) represents an alternative to immunosuppression as a means of reducing rejection after thoracic organ transplantation. The mechanism by which ECP exerts its protective effects, until now, has remained elusive. Infusion of ECP-treated splenic lymphocytes (PUVA-SP) can induce CD4⁺CD25^highFoxp3⁺ regulatory T cells. However, the regulatory effect of PUVA-SP on B cells remains poorly understood. In the present study, we measured IL-10 secretion from CD19⁺ B cells of peripheral blood mononuclear cells. Our results demonstrate that infusion of PUVA-SP (PUVA-BSP from BALB/c or PUVA-CSP from C57BL/6 mice), in the absence of an immunosuppressant, significantly promotes skin allograft survival. This effect was associated with upregulation of circulating regulatory B cells exhibiting preferential IL-10 secretion and a shift of cytokine profile from helper T cell type 1 to helper T cell type 2. Our results suggest that effective treatments involving infusion of PUVA-SP is likely related not only to the modulation of T cell and regulatory T cell functions but also to the function of B cell and regulatory B cells.

Extracorporeal Photopheresis in the Treatment of Persistent Rejection in a Pediatric Lung Transplant Recipient

Lung transplantation is an accepted therapy for children with end-stage lung disease. One-year lung transplant survival rates of 86% have been reported by the United Network for Organ Sharing. Allograft rejection is a common cause of death following transplantation. Extracorporeal photopheresis is a novel therapy used to treat solid-organ rejection; this therapy involves separating the leukocyte-rich fraction from whole blood, treating with psoralen and ultraviolet light A exposure. The objective of therapy is to reverse progressive and persistent rejection. Working collaboratively with an institution that offers extracorporeal photopheresis may provide an alternative or additional therapy in the management of ongoing rejection following solid-organ transplantation.

Immunosuppression therapy for pediatric heart transplantation

OPINION STATEMENT

Outcomes following cardiac transplantation in childhood continue to improve. Advances in immunosuppressive therapy over the past two decades likely have contributed to this trend. The evolution in the management of immunosuppression in children has been based on clinical experience rather than on evidence-based medicine; indeed, there have been no pivotal randomized controlled trials of any form of immunosuppression in pediatric thoracic transplantation. Important trends in immunosuppressive therapy and transplant outcomes have been obtained from large transplant registries. Several trends have been identified since the last review of this topic in this journal. First, there is increased knowledge of the pharmacodynamics and pharmacokinetics of immunosuppressive drugs in children, with notable advances in the field of pharmacogenomics. These studies help explain individual variations in drug exposure, efficacy, and adverse events. They also help explain racial and ethnic variations in drug metabolism and efficacy. Second, there have been clear trends in the use of specific immunosuppressive medications. Use of induction therapy, especially polyclonal T cell-depleting antibody preparations, has increased significantly in recent years. The calcineurin inhibitor (CNI) tacrolimus is being used as the cornerstone of maintenance therapy in lieu of cyclosporine in more and more centers. Mounting evidence suggests that use of adjunctive agents (notably mycophenolate mofetil [MMF]) may improve outcomes, including survival, suggesting that monotherapy with CNIs is not the ideal maintenance therapy. Despite its increased cost, MMF has largely replaced azathioprine as the adjunctive agent of choice. Inhibitors of the mammalian target of rapamycin (i.e., sirolimus and everolimus) have not yet assumed a major place as adjunctive agents, as their safety and efficacy have not been well established in children. With the improvements in immunosuppressive therapy, the justification for routine corticosteroid use is far from clear, and many centers have shown excellent outcomes with complete steroid avoidance. Third, there is increasing interest in the importance of anti-HLA antibodies as important risk factors for adverse graft and patient outcomes. This is generating intense interest in treatments that target B cells and plasma cells. Finally, there is increasing realization that the "one size fits all" approach to immunosuppressive therapy is an obsolete concept and that the ultimate goal is to tailor immunosuppressive therapy to the needs of the individual patient. The development of reliable biomarkers of the patient's immune response to the allograft will be essential for optimal individualized immunosuppressive management.

Extracorporeal photopheresis for the treatment of steroid refractory acute GVHD

Extracorporeal photopheresis (ECP) was given to 23 patients with steroid-refractory acute GVHD (aGVHD, grade II (n=10), III (n=7) or IV (n=6)). The median duration of ECP was 7 months (1-33) and the median number of ECP cycles in each patient was 10. Twelve patients (52%) had complete responses. Eleven patients (48%) survived and 12 died, 10 of GVHD with or without infections and two of leukaemia relapse. The average grade of GVHD was reduced from 2.8 (on the first day of ECP) to 1.4 (on day +90 from ECP) (P=0.08), and the average dose of i.v. methylprednisolone from 2.17 to 0.2 mg/kg/d (P=0.004). Complete responses were obtained in 70, 42 and 0% of patients, respectively, with grades II, III and IV aGVHD; complete responses in the skin, liver and gut were 66, 27 and 40%. Patients treated within 35 days from onset of aGVHD had higher responses (83 vs 47%; P=0.1). A trend for improved survival was seen in grade III-IV aGVHD treated with ECP as compared to matched controls (38 vs 16%; P 0.08). ECP is a treatment option for patients with steroid refractory aGVHD and should be considered early in the course of the disease.

The first year post-heart transplantation: use of immunosuppressive drugs and early complications

A large number of heart transplants are performed annually in different transplant centers in the United States. This is partly because of the improved survival of patients who undergo cardiac transplantation, thus making it a more viable option in the management of end-stage heart failure. The survival benefit after heart transplantation is a result of newer immunosuppressive drug regimens and a better understanding of their effects and interactions. Several studies, mostly involving a small number of patients, describe use and comparison of the many distinct immunosuppressive drugs available to date. Interestingly, many transplant centers perform in-house typical induction treatment regimens because of their own experience and intra-institutional preference. This review summarizes current practices of immunosuppressive drug therapy in the first year post-heart transplant based on the available clinical evidence and discusses future options of heart transplant immunosuppressive drug therapies.

Review of extracorporeal photopheresis in early-stage (IA, IB, and IIA) cutaneous T-cell lymphoma

BACKGROUND

Extracorporeal photopheresis (ECP) has been used for nearly 20 years for the treatment of cutaneous T-cell lymphoma (CTCL). A substantial body of literature reports that this form of photoimmunotherapy improves or stabilizes the course of disease in a subset of patients across all stages. However, current clinical approach usually reserves ECP for patients who do not respond to other treatments or for patients with late-stage disease or Sézary syndrome (SS).

METHODS

A comprehensive Pubmed/Medline literature search was performed to identify studies reporting the use and efficacy of ECP in early stage (IA, IB, and IIA) CTCL. Information regarding prognostic factors and survival of early-stage patients treated with ECP was also obtained and summarized.

RESULTS

The heterogenous nature of the reports and lack of any prospective randomized trials made evaluation of response to treatment difficult. However, the current literature contains at least 124 early-stage patients treated with ECP or ECP plus adjuvant therapy from 1987-2007 in 16 different reports. Response rates of treatment for this patient population with ECP and ECP plus adjuvant therapy varied from 33-88%.

CONCLUSIONS

Given the very low side effect profile of ECP compared with other therapies and its demonstrated efficacy, this treatment modality is possibly beneficial for patients with earlier stages of CTCL. Randomized prospective studies are needed to establish the role of ECP in this disease subset.

Induction of regulatory T cells after prophylactic treatment with photopheresis in renal transplant recipients

Extracorporeal photopheresis (ECP), originally used to treat cutaneous T-cell lymphoma, also has been applied to the therapy of transplant rejection. Our aim was to investigate the biologic response in two children who underwent kidney transplantation with ECP as prophylactic treatment. They received conventional immunosuppressive therapy and ECP immediately after transplantation: six applications over the course of 3 weeks. During a 12-month follow-up, the clinical course was favorable in both patients; renal histology was normal 6 months after transplantation. When compared with four transplanted controls, the ECP-treated patients showed lower tumor necrosis factor-alpha serum levels in the short-term and a marked increase of Foxp3-positive T-regulatory cells. T-regulatory cells were still higher than in the controls 1 year after transplantation. These preliminary results suggest that the addition of ECP to standard immunosuppressive therapy induces a tolerogenic shift in the immune system of kidney transplanted patients and may pave the way to preventing chronic rejection.

Refractory acute renal allograft rejection successfully treated with photopheresis

INTRODUCTION

Acute rejection episodes still occur in spite of modern immunosuppressive protocols. We present seven patients with biopsy-proven acute rejections after kidney transplantation refractory to repeated pulses of high-dose steroids and antithymocyte globulin (ATG) or OKT-3, but responsive to photopheresis therapy.

METHODS

Photopheresis is a nontoxic immunomodulatory, apheresis-based treatment with no general immunosuppressive action. Rather, it suppresses specific pathogenic T-cell clones. During photopheresis mononuclear leukocytes are collected from the patient using centrifugation technique, treated with a photosensitizing agent, irradiated, and subsequently retransfused.

RESULTS

All patients tolerated the treatment well, with no notable side effects. At the 12-month follow-up the median creatinine had decreased to 161 mumol/L compared to 282 mumol/L at the start of photopheresis and at the last follow-up 12 to 43 months after transplantation all patients still had functioning grafts. In five of the seven cases there had been a significant improvement in renal function, whereas in two of the patients the renal function remained stable but without a decrease in creatinine.

CONCLUSIONS

It is our experience that the prognosis for renal allografts with acute rejection unresponsive to conventional antirejection treatment (ie, repeated pulses of methylprednisolone and ATG or OKT-3) is very poor. Therefore, we conclude that the photopheresis treatment contributed to the favorable outcome in this small group of patients. We are presently designing a prospective randomized study to further evaluate the effect of photopheresis after renal transplantation.

The immunological effect of photopheresis in children with newly diagnosed type 1 diabetes

Photopheresis has been claimed to have immune-modulating effects, but the mechanisms of action are unknown. This study investigated the immune effect of photopheresis in children with type 1 diabetes, with a focus on the balance of Th1- and Th2-like cytokines. Ten children with newly diagnosed type 1 diabetes (10-17 y) were treated with five double treatments of photopheresis and 10 children matched for disease, age, and gender were given placebo tablets and sham pheresis. Expression of IFN-gamma and IL-4 mRNA was determined by real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and secretion of IFN-gamma, IL-10, and IL-13 in cell-culture supernatants by ELISA after stimulation with glutamic acid decarboxylase (GAD65) (a.a. 247-279), the ABBOS peptide (a.a. 152-169), insulin, phytohemagglutinin (PHA), and keyhole limpet hemocyanin (KLH). Photopheresis changed antigen-stimulated immune balance in line with a Th2-like shift. Thus, the ratio of IFN-gamma/IL-4 mRNA expression after in vitro stimulation with a peptide of the autoantigen GAD65 was reduced after treatment in the photopheresis group. The IFN-gamma/IL-4 mRNA expression ratio after in vitro stimulation with insulin was also lower in children treated with photopheresis compared with the placebo group. Photopheresis has an immune-modulating effect in children with type 1 diabetes, causing a Th2-like deviation.

The Immunological Effects of Extracorporeal Photopheresis Unraveled: Induction of Tolerogenic Dendritic Cells In Vitro and Regulatory T Cells In Vivo

Extracorporeal photopheresis (ECP) may represent an alternative to immunosuppression, as a means of reducing rejection after thoracic organ transplantation. The mechanism by which ECP exerts its protective effects has, until now, remained elusive. We analyzed peripheral blood mononuclear cells of four children with chronic heart and lung transplant rejection, who received ECP in addition to conventional immunosuppressive treatment. The effects of ECP were evaluated at each cycle, comparing blood samples from the same patient collected before and after treatment. In vitro, peripheral blood mononuclear cells treated with ECP undergo apoptosis and are phagocytosed by immature dendritic cells, which, in turn, acquire a tolerogenic phenotype. The frequency of T cells, with a regulatory phenotype and strong suppressive activity, was significantly increased in the blood of ECP-treated patients. The immunomodulatory effects of ECP may be explained by its ability to increase the frequency of regulatory T cells with inhibitory action on transplant immune rejection.

Photopheresis for the treatment of refractory renal graft rejection

Acute rejection episodes still occur after kidney transplantation in spite of modern immunosuppressive protocols including combined tacrolimus, mycophenolate mofetil, and prednisolone. The authors present seven cases of biopsy-proven acute rejection after kidney transplantation refractory to conventional rejection therapy with repeated pulses of high-dose steroids followed by polyclonal or monoclonal antibodies that responded well to photopheresis treatment. Photopheresis is an atoxic immunomodulatory apheresis-based treatment with no generalized immunosuppressive action; rather, it is directed at suppressing donor-specific T-cell clones. At the last follow-up, 9 to 43 months after transplantation, all patients had functioning grafts, with serum creatinine levels ranging from 105 to 312 microM. The authors conclude that photopheresis treatment contributed to the favorable outcome. Therefore, the authors are presently designing a prospective, randomized trial to evaluate the effect of photopheresis as an adjuvant prophylactic treatment after renal transplantation.

A randomized cross-over study to compare PUVA and extracorporeal photopheresis in the treatment of plaque stage (T2) mycosis fungoides

PUVA is a well-established and effective treatment for plaque stage mycosis fungoides (MF) but its use is limited on a long-term basis because of the risk of cutaneous carcinogenesis. A further disadvantage is that nonexposed areas (sanctuary sites) often develop persistent disease. Therefore it is important to find alternative methods of treatment. Extracorporeal photopheresis (ECP) is a form of photochemotherapy that involves exposure of white blood cells to UVA with psoralens and can be effective in Sézary syndrome and erythrodermic cutaneous T-cell lymphoma. The aim of this study was to compare the efficacy of PUVA and ECP in the treatment of patients with T2 plaque stage (Stage 1B) MF who had a detectable peripheral blood T-cell clone. The study was of a cross-over design. Sixteen patients were randomized to receive either PUVA twice weekly for 3 months followed by ECP once monthly for 6 months at relapse, or vice-versa. Response was assessed by monthly skin scores and peripheral blood T-cell clonality. Ten patients received PUVA initially and six ECP initially. Eight patients completed the study. Skin scores taken at the completion of each treatment arm in patients who completed the study were 113 units better (confidence interval, 42-184 units) following 3 months PUVA than 6 months ECP (P = 0.002). Peripheral blood T-cell clones were detectable in all patients post-treatment. This study indicates that ECP is not effective in the treatment of plaque stage (1B/T2) MF even in patients with molecular evidence of a peripheral blood T-cell clone. Although PUVA was more effective than ECP, neither treatment modality cleared malignant T-cells from the peripheral blood.

Extracorporeal photopheresis in the treatment of persistent rejection in a pediatric lung transplant recipient

Lung transplantation is an accepted therapy for children with end-stage lung disease. One-year lung transplant survival rates of 86% have been reported by the United Network for Organ Sharing. Allograft rejection is a common cause of death following transplantation. Extracorporeal photopheresis is a novel therapy used to treat solid-organ rejection; this therapy involves separating the leukocyte-rich fraction from whole blood, treating with psoralen and ultraviolet light A exposure. The objective of therapy is to reverse progressive and persistent rejection. Working collaboratively with an institution that offers extracorporeal photopheresis may provide an alternative or additional therapy in the management of ongoing rejection following solid-organ transplantation.