Extracorporeal photopheresis (ECP) in the treatment of chronic graft-versus-host disease (GVHD)

Extracorporeal photopheresis: a review

Extracorporeal phototherapy (ECP) is a therapeutic approach based on the biological effect of psoralen 8-methoxypsoralen (8-MOP) and ultraviolet light A (UVA) on mononuclear cells collected by apheresis, and reinfused into the patient. Photopheresis is widely used for the treatment of patients with advanced cutaneous T-cell lymphoma (CTLC). Evidence suggests that it prolongs life, and also induces 50-75% response rates. In addition, more and more reports indicate that photopheresis is a potent agent in the therapy of acute allograft rejection among cardiac, lung and renal transplant recipients. There are increasing amounts of data showing that patients with chronic graft versus host disease benefit from this therapy. Likewise, there are indications that there may be a potential role for ECP in the therapy of certain autoimmune diseases resistant to conventional therapy. The mechanism of this treatment is likely due to the induction of anticlonotypic immunity directed against pathogenic clones of T lymphocytes. Treatment induces apoptotic death of pathogenic T-cells, and it is postulated that activation of antigen-presenting cells has important effects in this process.

Novel approaches to the treatment of chronic graft-versus-host disease

Chronic graft-versus-host disease (cGvHD) continues to be the major problem in long-term survivors of allogeneic haematopoietic stem cell transplants and is the principal cause of morbidity and non-relapse mortality. Over the past twenty years, diagnosis, prophylaxis and treatment of cGvHD have slowly evolved. An effective therapy for cGvHD is designed to prevent complications through targeting the disease mechanisms. None of the present therapies for cGvHD are successful in the majority of patients. Conventional drugs in different combinations can control the disease in approximately 50% of patients. Attempts to improve survival have led to evaluation of several alternative approaches in the treatment of refractory cGvHD with varying degrees of success. Clinical trials are needed to establish the role of these new approaches in the treatment of cGvHD as first line or salvage therapy without causing significant side effects. This review summarises the currently available knowledge on conventional and new treatment approaches for cGvHD.

Cutaneous T-cell lymphoma and cutaneous graft-versus-host disease. Two indications for photopheresis in dermatology

Dermatologists are frequently involved in the management of cutaneous T-cell lymphoma (CTCL) and graft-versus-host disease (GVHD). The similarities of these two entities are reviewed in the context of clinical and histologic findings, pathogenesis, and therapy. Photopheresis therapy (extracorporeal photochemotherapy) is used in the treatment of both entities, and the mechanisms underlying the responses represent yet another striking similarity of these two crippling dermatologic diseases.

Macroscopic and microscopic mucinosis in chronic sclerodermoid graft-versus-host disease

Secondary cutaneous mucinosis is a well-recognized feature of connective tissue diseases such as lupus erythematosus and dermatomyositis. We report the first three cases of dermal mucinosis in association with severe chronic cutaneous graft-versus-host disease of the sclerodermoid variety. One patient had clinical changes due to abundant mucin accumulation within the papillary dermis (mucinoma). In the other two patients histological examination revealed extensive deposits of mucin predominantly within the reticular dermis. The microscopic appearances were striking, with numerous vacuolated spaces interspersed between collagen bundles. We speculate that this appearance is the result of ground substance becoming trapped within grossly sclerodermoid connective tissue.

Extracorporeal photochemotherapy in the treatment of severe graft-versus-host disease

Advances in posttransplant immunosuppression have to the present not been able to prevent the development of graft-versus-host disease (GVHD) in patients given related or unrelated stem cell grafts for cure of hematologic diseases. Patients with GVHD not responding to first line therapy with corticosteroids remain at high risk of death due to severe infections or organ failure. Extracorporeal exposure of peripheral blood mononuclear cells to the photosensitizing agent 8-methoxypsoralen and ultraviolet A radiation has been shown to be effective in treatment of selected T-cell mediated diseases, including cutaneous T-cell lymphoma and rejection after organ transplantation. Extracorporeal photochemotherapy (ECP) is also a safe and efficacious adjunct therapy for both acute and chronic extensive GVHD with skin and visceral involvement and resistance to conventional immunosuppressive therapy. A multicenter randomized study should help define the impact of ECP in the treatment of GVHD and overall survival of these patients.