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

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.

A standardized methodical approach to characterize the influence of key parameters on the in vitro efficacy of extracorporeal photopheresis

Extracorporeal photopheresis (ECP) is an autologous immunomodulatory cell therapy that consists of the ex vivo collection of mononuclear cells (MNCs), which are irradiated with UVA in the presence of the photosensitizing agent 8-methoxypsoralen (8-MOP) to induce cell apoptosis. This photoactivated cell preparation is then reinfused into the patient. While the clinical benefits of ECP are well-demonstrated, no study has yet characterized the influence of variations in the composition of the cell preparation on the efficacy of ECP in vitro. Here, we describe a standardized methodology for the in vitro assessment of ECP that uses the human lymphoma T-cell line and mimics the clinical procedure. By quantifying cell apoptosis, inhibition of cell proliferation, and 8-MOP consumption, we used this approach to characterize the specific influence of key variables on the cellular response to ECP. We found that (i) increases in hematocrit and plasma concentrations attenuated the cellular response to ECP; (ii) plasma concentration was the only variable tested that influenced 8-MOP consumption; and (iii) the loss of efficacy due to variations in the concentration of certain blood components could be counteracted by modulating the UVA dose. This methodology may enable evaluation of other leukapheresis preparation protocols and better determination of the optimal working parameters for ECP.

Extracorporeal Photopheresis Improves Survival in Hematopoietic Cell Transplant Patients with Bronchiolitis Obliterans Syndrome without Significantly Impacting Measured Pulmonary Functions

We carried out the first matched retrospective cohort study aimed at studying the safety and efficacy of extracorporeal photopheresis (ECP) for bronchiolitis obliterans syndrome (BOS) after allogeneic hematopoietic cell transplantation (HCT). Medical records of 1325 consecutive adult patients who underwent HCT between 2005 and 2015 were reviewed. Seventy-four patients (median age, 51 years) with a diagnosis of BOS were included in the study. After propensity-score matching for BOS severity, 26 patients who underwent ≥3 months of ECP were matched to 26 non-ECP-treated patients, who were assigned an index date corresponding to the ECP start date for their matched pairs. The rate of decline in FEV₁ percentage predicted (FEV_1PP) decreased after ECP initiation (and after index date in the non-ECP group), with no significant difference between the 2 groups (P = .33). On a multivariable analysis that included baseline transplant and pulmonary function test variables, matched related donor HCT (HR, .1; 95% CI, .03 to .5; P = .002), ECP (HR, .1; 95% CI, .01 to .3; P = .001), and slower rate of decline in FEV_1PP before the ECP/index date (HR, .7; 95% CI, .6 to .8; P = .001) were associated with a better overall survival. At last follow-up, non-ECP-treated patients were more likely to be on >5 mg daily dose of prednisone (54% versus 23%; P = .04) and had a greater decline in their Karnofsky performance score (mean difference, -9.5 versus -1.6; P = .06) compared with ECP-treated-patients. In conclusion, compared with other BOS-directed therapies, ECP was found to improve survival in HCT patients with BOS, without significantly impacting measured pulmonary functions. These findings need prospective validation in a larger patient cohort.

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

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

Extracorporeal photopheresis 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.

Previously Activated Psoralen: A Possible Novel Format of Psoralen Used in the Treatment of Graft-versus-host Disease

Graft-versus-host disease (GVHD) is a lethal complication of allogeneic haematopoietic stem cell transplantation which limits its application. Psoralen was utilized in the treatment of GVHD as a second-line method, which is also known as extracorporeal photochemotherapy (ECP). In the process of ECP, mononuclear cells must be isolated from the body in advance then a photosensitizer, 8-methoxypsoralen (8-MOP, 200 μg/L for the final concentration), would be added to the cell suspension before its exposure to ultraviolet A [UVA; 365 nm, 2J/cm2]. The disposed lymphocytes re-infused into the body account for 5% to 15% of the lymphocytes in the body. The process of ECP is complicated, expensive and very labour intensive, which limits its popularity. We hypothesized that psoralen should be activated by ultraviolet A, and should be kept in activation for a relatively long time before it gets in contact with mononuclear cells. This kind of psoralen is called previously activated psoralen (PAP), which may have the same effects on GVHD as ECP, but would be much easier and economical to work with.

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. 

Extracorporeal photopheresis in the treatment of graft-versus-host disease: evidence and opinion

Despite significant advances in prevention and treatment strategies, graft-versus-host disease remains the most significant cause of morbidity and nonrelapse mortality after allogeneic hematopoietic cellular transplantation. Corticosteroids remain the standard frontline therapy for graft-versus-host disease; however, a considerable number of patients will not respond adequately and others will be significantly affected by adverse effects. Extracorporeal photopheresis is one of several secondary therapies which have shown promise in the clinical setting. While the procedure itself has been around for over 20 years, our understanding of the mechanisms from which therapeutic benefits are seen, and the population they are seen in, remains limited. In this article, we review the use of extracorporeal photopheresis for the treatment of graft-versus-host disease including details covering the procedure's mechanism of action, safety profile and clinical efficacy data.

Extracorporeal photopheresis in a rat model of pulmonary fibrosis

Extracorporeal photopheresis has anti-inflammatory properties. The development of pulmonary fibrosis includes inflammatory episodes. This study evaluates effects of extracorporeal photopheresis in experimental pulmonary fibrosis. The bleomycin model of pulmonary fibrosis was used. Two groups of 4 rats received intratracheal bleomycin to induce fibrosis. The treatment group received infusions of photochemically treated leukocytes harvested from syngeneic animals. All animals were sacrificed at day 21 after fibrosis induction and analyzed with respect to lung histology and hydroxyproline content, cellular composition of bronchoalveolar lavages, serum and lavage concentrations of transforming growth factor-beta, interferon-gamma, and interleukin-10, and expression of selected genes in the lung. Interleukin-10 and transforming growth factor-beta protein concentrations increased in the plasma of treated animals, whereas the interferon-gamma protein concentration was higher in bronchoalveolar lavages. Interferon-gamma gene expression was up-regulated in the lung tissue of treated animals. No significant differences between treated and untreated animals were found with respect to hydroxyproline, histology, and lavage cell count. To conclude, extracorporeal photopheresis has positive molecular effects but does not attenuate experimental lung fibrosis with respect to histology, hydroxyproline, and lavage cell count in the applied treatment regimen. Further investigations of extracorporeal photopheresis in experimental pulmonary fibrosis are justified.

Reciprocal modulation of circulating CD4+CD25+bright T cells induced by extracorporeal photochemotherapy in cutaneous T-cell lymphoma and chronic graft-versus-host-disease patients

The mechanisms of action of extracorporeal photochemotherapy (ECP) in cutaneous T-cell lymphoma (CTCL) are poorly understood. Recently, ECP has been shown to induce an increase in regulatory T cell (Treg) expression and functional activities in Graft-versus-host-disease (GvHD), whereas no data are available in CTCL patients. The aim of this study is to evaluate whether ECP is able to modulate the expression levels of the circulating CD4+CD25+bright subset in CTCL patients and whether these modifications are related to the disease course. The patient population included 43 CTCL and 15 chronic GvHD patients treated by ECP at our institutions since 1992. The expression of the circulating CD4+CD25+bright subset was analysed at baseline and sequentially during treatment by flow-cytometry. Fifty healthy donors were used as controls. The baseline circulating CD4+CD25+bright percentage values in CTCL (median: 4.3 percent) were similar to those of healthy donors, whereas GvHD showed significantly lower values (median: 1.5 percent; p<0.001). During treatment, CTCL patients were characterised by an early decrease (from 4.3 percent to 2.4 percent median after 6 months). The CD4+CD25+bright decrease was associated to the disease course, as it occurred in 91.3 percent of responding but in only 25 percent of PD patients (p=0.0001). On the other hand, a significant increase of CD4+CD25+bright cells was observed in GvHD. ECP induces a reciprocal modulation of the circulating CD4+CD25+bright cells in CTCL and GvHD, with a downregulation in CTCL potentially associated with the response mechanisms.

[Steroid-refractory graft-versus-host disease: extracorporeal irradiation of leucocytes induces immunotolerance]

A 42 year-old woman develops steroid refractory graft-versus-host disease (GVHD) after second allogeneic stem cell transplantation for acute myelogenous leukemia with severe GVHD of her skin with blisters, severe GVHD of her gut with watery and bloody diarrhea and GVHD of her liver with cholestasis. In a further attempt to control GVHD extracorporeal photochemotherapy is administered. The treatment exposures peripheral mononuclear cells to photoactivated psoralen before they subsequently are given back to the patient. This approach apparently offers selective immune tolerance.

Extracorporeal photopheresis in graft-versus-host disease

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

Photopheresis in pediatric graft-versus-host disease after allogeneic marrow transplantation: clinical practice guidelines based on field experience and review of the literature

BACKGROUND

Extracorporeal photochemotherapy (ECP) gives positive results in the management of graft-versus-host disease (GVHD), but in children, specific difficulties can outweigh this benefit. These difficulties must be taken into consideration when establishing a standardized reproducible procedure for implementation under a quality management plan.

STUDY DESIGN AND METHODS

Twenty-seven children underwent ECP for severe acute GVHD (aGVHD) or chronic GVHD (cGVHD) after allogeneic marrow transplantation. Data were collected prospectively, with particular emphasis placed on technical, biologic, immunologic, clinical, and long-term follow-up issues.

RESULTS

The 27 children underwent a total of 750 sessions. Mononuclear cells were collected on a commercially available apheresis system (COBE Spectra, Gambro BCT). Overall survival was 73 percent, and ECP led to significant improvement in 21 of the 27 patients (11 with complete response and 10 with partial response, i.e., >50% of organ involvement). Tolerance was good overall, the main limiting factors being vascular access and the psychological impact of repeated apheresis procedures. Children weighing less than 25 kg were not more susceptible to side effects.

CONCLUSION

A specifically pediatric-dedicated and -experienced team faces only limited difficulties when treating children with GVHD by ECP. Overall, ECP is efficient and well tolerated. Our experience was therefore pooled together with available pediatric data to establish clinical practice guidelines. These guidelines consider ECP as a first-line therapy in Grade IV aGVHD (in association with conventional pharmacologic approaches) and limited cGVHD and as a second-line therapy in steroid-resistant Grades II to III aGVHD and extensive cGVHD.

Sclerodermatous graft-versus-host disease: clinical spectrum and therapeutic challenges

Sclerodermatous graft-versus-host disease (GVHD) is a rare complication of bone marrow transplantation. While GVHD is often associated with the beneficial graft vs. tumour effect, it also contributes towards significant morbidity and mortality. No reliably effective treatment has yet been established. We present 10 patients with haematological malignancies who underwent an allogeneic stem cell transplant and developed sclerodermatous GVHD. Donor lymphocyte infusion administered for relapse or reducing donor T-cell chimerism was a known trigger for sclerodermatous GVHD in four of the patients. Treatment with immunosuppressants, psoralen plus ultraviolet A (PUVA) and extracorporeal photopheresis has been largely unsuccessful in their management. Intensive immunosuppression including the use of anti-CD20 monoclonal antibody may have contributed to relapse of leukaemia in one patient 10 years after her transplant. Sclerodermatous GVHD may occur without a preceding lichenoid stage. Clinical heterogeneity is common, although sclerodermatous GVHD has a predilection for the limbs. Treatment options are largely unsatisfactory if conventional immunosuppression fails. PUVA may give some symptomatic benefit and extracorporeal photopheresis seems to be less efficacious than previously published work suggests.

Treatment of refractory erosive oral lichen planus with extracorporeal photochemotherapy: 12 cases

BACKGROUND

Case reports have suggested that extracorporeal photochemotherapy (ECP) might be beneficial for the treatment of erosive oral lichen planus (OLP) recalcitrant to conventional immunosuppressive therapies.

OBJECTIVES

To evaluate over a long-term period the clinical efficacy and toxicity of ECP in a series of patients with refractory OLP, and to monitor peripheral blood lymphocyte subset counts under treatment.

METHODS

Twelve patients with refractory OLP underwent a standardized protocol of ECP. Sessions were performed twice weekly for 3 weeks, and then the treatment schedule was adapted according to clinical benefit. The disease severity was evaluated monthly on a clinical basis. Complete remission was defined as the absence of any erosion and partial remission as a decrease of at least 50% of erosion surface. Blood cell counts with CD4+ and CD8+ lymphocyte subsets were evaluated every 3 months.

RESULTS

All patients showed a decrease of the erosive surface; nine (75%) achieved a complete remission and three (25%) a partial remission. Seven of the eight patients followed for more than 3 years had recurrences of erosions when ECP sessions became less frequent or were stopped. After resumption of an initially accelerated regimen of ECP, all again showed partial or complete remission. Blood lymphocyte counts decreased during treatment, without statistically significant changes in CD4+/CD8+ ratio, and increased during relapse.

CONCLUSIONS

ECP is an effective alternative therapy in erosive OLP showing resistance to classical treatments. The decrease in blood lymphocyte counts appears to parallel the clinical improvement under treatment.

Assessment of 8-methoxypsoralen and ultraviolet a light effects on human stroma generation and function

Photopheresis or extracorporeal photochemotherapy (ECP) is a new immunomodulatory therapy in which a patient's leukocytes are exposed extracorporeally to 8-methoxypsoralen (8-MOP) and ultraviolet A (UVA) light. Although it is used for the treatment of cutaneous T cell lymphoma, graft-versus-host disease, and several autoimmune diseases, with efficacy and safety reported in almost all studies, the mechanisms by which ECP exerts its beneficial effects are still unclear. As cellular targets of this procedure are numerous, we investigated the effects of 8-MOP and UVA light on stromal precursors and mature stromal layers. Human bone marrow stromal cell layers were established in long-term bone marrow culture medium from normal marrow mononuclear cells. Normal marrow mononuclear cells were incubated with 8-MOP and/or exposed to UVA light (PUVA treatment) before culturing. A control without 8-MOP and UVA was also included in the study. Apoptosis induction was evaluated using annexin V following 7 days after PUVA. After 4-6 weeks of culture, stromal layers were examined under a phase-contrast microscope to identify structural differences between PUVA-treated and control stroma. To determine whether PUVA treatment affected stromal regulation of adherent hematopoietic cell survival, mature stromal layers, incubated with 8-MOP and exposed to UVA light, were cocultured with nonadherent mononuclear cells from normal marrow. After 24 h, the percentage of apoptotic hematopoietic cell precursors was quantified by flow cytometry. This study provides evidences that the in vitro exposure of human stromal cell precursors to UVA light, in the presence of 8-MOP, inhibits stromal layer generation by inducing apoptosis, as evidenced by annexin V staining following 7 days of culture. Here, we show an additional cell target for this psoralen following UVA irradiation. However, in a second set of experiments, PUVA treatment did not affect the stromal capacity to support hematopoiesis in culture. Our results can contribute to a better definition of ECP mechanisms of action for future development of experimental designs and clinical applications of this intriguing procedure.

Treatment of extensive chronic graft-versus-host disease with extracorporeal photochemotherapy

Extracorporeal photochemotherapy (ECP; photopheresis), an immunomodulatory therapy developed for cutaneous T-cell lymphoma, has shown promise in treating chronic graft-versus-host disease (cGvHD) in uncontrolled studies. The purpose of this study was to further examine the effects of ECP on cGvHD. ECP (administered initially 3 times weekly on alternating days) was retrospectively evaluated in 14 patients with extensive cGvHD following allogeneic hematopoietic stem cell transplantation. The median time from transplantation to ECP initiation was 29 months (range, 5-96 months). The median number of concomitant baseline treatments per patient was 3 (range, 0-5). During a median ECP duration of 17 months (range, 3-44 months), 3 patients (21%) achieved a complete cutaneous response (100% improvement), 4 patients (29%) achieved a partial cutaneous response (> or =50% improvement), and 7 patients (50%) had stable skin disease. The median time to response was 6 months (range, 2-15 months), and the median response duration was 5 months (range, 1-31 months). At endpoint, responses were ongoing in 4 patients. Resolution or improvement was noted in arthralgia (5/7 patients), oral changes (3/7), elevated liver enzymes (3/5), dry eyes (2/5), joint stiffness (3/3), pulmonary disease (1/3), and thrombocytopenia (1/1). Because of a favorable response, 11 of 13 patients (85%) who received prednisone at baseline were able to taper (7/13; 54%) or discontinue (4/13; 31%) this medication, and 12 of 14 patients (86%) were able to taper (11/14; 79%) or discontinue (1/14; 7%) ECP. Five-year posttransplantation survival was 77%. Our results suggest that adjunctive ECP improves cutaneous and extracutaneous manifestations of cGvHD and has a steroid-sparing effect.

Extracorporeal photopheresis: A focus on apoptosis and cytokines

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

Extracorporeal photochemotherapy for the treatment of steroid-resistant chronic GVHD

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

Chronic graft versus host disease of oral mucosa: Review of available therapies

The use of hematopoetic stem cell transplantation (HSCT) has greatly expanded in the recent years for many neoplastic and hematological disorders. Chronic graft versus host disease (cGVHD) is a major complication of allogeneic HSCT and a major cause of morbidity and mortality. Oral mucosal involvement is frequent in cGVHD and contributes significantly to the overall burden of the condition. Oral medicine professionals should be familiar with various treatment options for oral cGVHD. This review discusses treatment modalities available for the management of oral mucosal manifestations of cGVHD. Available evidence for efficacy and safety of various systemic and topical agents, including corticosteroids, calcineurin antagonists, mycophenolate mofetil, and extracorporeal photopheresis, is reviewed.

Role of extracorporeal photochemotherapy in patients with refractory chronic graft-versus-host disease

Recent studies suggest that extracorporeal photochemotherapy (ECP) may be beneficial in patients with steroid-refractory chronic graft-versus-host disease (cGvHD). However, it is not yet clear whether certain conditions, such as age, mode of onset of cGvHD etc., influence clinical response and whether certain affected organs are more sensitive to ECP than others. We analysed the main clinical and laboratory parameters related to evolution of the disease in 32 steroid-refractory cGvHD patients, to identify any useful response predictors to ECP. ECP affected the course of the disease positively in 78% (25/32) of our cases.