Photoactivational cytokine-modulatory action of 8-methoxypsoralen plus ultraviolet A in lymphocytes, monocytes, and cutaneous T cell lymphoma cells

Extracorporeal Photopheresis: A Case of Immunotherapy Ahead of Its Time

Extracorporeal photopheresis (ECP) is a cell-based immunotherapy that involves the reinfusion of autologous leukocytes after exposure to psoralen and UVA. The treatment has been used for over 30 years, at first on patients with cutaneous T-cell lymphoma (CTCL) and later for the management of patients with graft-versus-host disease (GvHD), sclerosing disorders, atopic dermatitis, and other diseases that may share the common driving factor of a pathogenic T-cell clone or clones in blood circulation. Patients with clinical improvement mount an antigen-specific immune response that may have tolerance traits in the case of GvHD or anticlonal cytotoxic characteristics in the case of CTCL. The exact mechanisms that dictate one response or the other are not fully understood, but the evidence accumulated so far indicates that multiple events occur simultaneously and consequentially contribute to the end result. These include contact of cells with the outside (plastics and tubing of the ECP apparatus), exposure to psoralen and UVA that activates platelets, monocytes, and other myeloid cells, the release of damage-associated molecular patterns, differentiation of monocytes into dendritic cells, and generation and successive presentation of numerous antigens after the phagocytosis of apoptotic cells. Once reintroduced, the ECP product increases the frequency and activity of regulatory T cells (Tregs), shifts the systemic cytokine balance, and promotes extravasation of immune cells that together shape the effects of this treatment. In this review, we summarize the seminal work and most recent literature of the therapeutic mechanisms and reflect on future avenues of improvements and applications of ECP.

Under ambient UVA exposure, pefloxacin exhibits both immunomodulatory and genotoxic effects via multiple mechanisms

Pefloxacin (PFLX) is an antibiotic, which shows broad spectrum antimicrobial activities. It is an important derivative of fluoroquinolones (FLQs) group. Ultraviolet radiation (200-400nm) causes major problem for living being which comes at the earth surface naturally through sunlight and increasing regularly due to ozone depletion. PFLX was photodegraded in 5h and forms photoproduct under UVA exposure. At the non photocytotoxic dose PFLX, shows reduced phagocytosis activity, NO (nitric oxide) production, large vacuole formation and down regulated IL-6, TNF-α and IL-1 in BALB/c macrophages at both genes and proteins levels. At higher doses (photocytotoxic doses), PFLX induced a concentration dependent decrease in cell viability of human keratinocyte cell line (HaCaT) and peritoneal macrophages of BALB/c mice. Our molecular docking suggests that PFLX binds only to the cleaved DNA in the DNA-human TOP2A complex. Topoisomerase assay confirmed that PFLX inhibits human topoisomerase by forming an adduct with DNA. Photosensitized PFLX also caused intracellular ROS mediated DNA damage and formation of micronuclei and cyclobutane pyrimidine dimers (CPDs). Increase intracellular ROS leads to apoptosis which was proved through lysosomal destabilization and reduced mitochondrial membrane potential (MMP). Our present study shows that ambient UVA exposure in the presence of PFLX caused immunomodulatory as well as photogenotoxic effects. Therefore, patients under PFLX drug treatment should avoid sunlight exposure, especially during peak hours for their photosafety.

Phototherapy in systemic sclerosis: Review

Systemic scleroderma-also known as systemic sclerosis (SSc)-is a chronic systemic connective tissue disease characterized by collagen deposition in cutaneous and internal organs, leading to skin sclerosis and multiple organ fibrosis. The pathogenesis is complex and remains poorly understood. Treatment is based on organ involvement and requires a multidisciplinary approach. Skin sclerosis can cause disability, leading to decreasing quality of life. Various systemic antifibrotic therapies have been used; however, most have unsatisfactory results. Recently, phototherapy and in particular ultraviolet A (UVA) has been used to treat skin sclerosis in SSc patients with satisfactory results. The main mechanisms include lymphocyte apoptosis, cytokine alteration, inhibition of collagen synthesis and increased collagenase production, and neovascularization, leading to the breakdown of collagen fibrils resulting in skin softening or even healing digital ulcers. Most studies reported that psoralen plus UVA (PUVA) and UVA1 phototherapy improved clinical outcomes vis-à-vis skin sclerosis, joint mobility, ulcers, and histopathology. PUVA and UVA1 phototherapy therefore have potential as an alternative or adjunctive therapy for patients with SSc.

Primary cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome): part II. Prognosis, management, and future directions

Both mycosis fungoides (MF) and Sézary syndrome (SS) have a chronic, relapsing course, with patients frequently undergoing multiple, consecutive therapies. Treatment is aimed at the clearance of skin disease, the minimization of recurrence, the prevention of disease progression, and the preservation of quality of life. Other important considerations are symptom severity, including pruritus and patient age/comorbidities. In general, for limited patch and plaque disease, patients have excellent prognosis on ≥1 topical formulations, including topical corticosteroids and nitrogen mustard, with widespread patch/plaque disease often requiring phototherapy. In refractory early stage MF, transformed MF, and folliculotropic MF, a combination of skin-directed therapy plus low-dose immunomodulators (eg, interferon or bexarotene) may be effective. Patients with advanced and erythrodermic MF/SS can have profound immunosuppression, with treatments targeting tumor cells aimed for immune reconstitution. Biologic agents or targeted therapies either alone or in combination--including immunomodulators and histone-deacetylase inhibitors--are tried first, with more immunosuppressive therapies, such as alemtuzumab or chemotherapy, being generally reserved for refractory or rapidly progressive disease or extensive lymph node and metastatic involvement. Recently, an increased understanding of the pathogenesis of MF and SS with identification of important molecular markers has led to the development of new targeted therapies that are currently being explored in clinical trials in advanced MF and SS.

Recurrence of mycosis fungoides on multiple melanocytic nevi: a case report and review of the literature

Melanocytic nevi represent a widespread cutaneous finding. Nevertheless, the presence of mycosis fungoides and melanocytic nevi in the same location is an extremely rare event. We report the case of a patient affected by mycosis fungoides and treated with PUVA therapy, with complete remission of the disease. Eight years after therapy discontinuation, he presented epidermal scaling and an erythematous perinevic halo on 3 old melanocytic lesions, the clinical aspect of which was highly suggestive for Meyerson nevi. The histological and immunohistochemical examination of an excised melanocytic lesion revealed histological features consistent with the diagnosis of mycosis fungoides superimposed on junctional melanocytic nevi. The finding of patches of mycosis fungoides superimposed on melanocytic nevi is a rare event; the confounding clinical appearance with eczematous changes around a pre-existing nevus may recall the halo dermatitis known as Meyerson phenomenon; this highlights the importance of clinical and histological examination to make the correct diagnosis of dermatological diseases.

Photopheresis therapy for problematic renal allograft rejection

BACKGROUND

Photopheresis is an immunomodulatory therapy for the treatment of T cell-mediated disorders. It has been used for rejection prophylaxis in cardiac transplantation, adjuvant treatment of bronchiolitis obliterans in lung transplantation, treatment of graft verse host disease, and in a small number of cases, for treatment of acute rejection in renal transplantation. Little is known of long-term outcomes following the use of photopheresis in solid organ transplantation.

METHODS

We report prospective follow-up of our consecutive experience of the use of photopheresis as adjuvant/salvage therapy for problematic rejection in patients undergoing renal transplantation. Transplant graft survival, infective and malignant outcomes were reported.

RESULTS

A cohort of 10 renal transplants recipients received photopheresis therapy for therapy-resistant rejection. Conventional therapy included an average of 6.2 g pulse methyl-prednisolone and 17.1 days antilymphocyte therapy. The cohort received additional photopheresis therapy when the unresponsive nature of their rejections raised concerns of graft loss. Median follow-up censored for patient loss was 66.7 months following photopheresis commencement. Rejection resolved in association with photopheresis use in all 10 patients. Six patients continued to have stable graft function (median serum creatinine: 191.5 micromol/L) at a median follow-up of 71.0 months. There has been one patient death from sepsis and two from malignancy with functioning grafts while one graft has been lost to disease recurrence.

CONCLUSION

Photopheresis may have a role as an adjuvant or salvage antirejection therapy in solid organ transplantation. Furthermore, evaluation in randomized controlled clinical trials is required to evaluate its potential.

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.

Micose fungóide: estudo epidemiológico de 17 casos e avaliação da resposta terapêutica à PUVA

FUNDAMENTOS: A fotoquimioterapia com PUVA é indicada para tratamento da micose fungóide, empregada como monoterapia em estágios precoces ou combinada a outras drogas nos estágios mais avançados da doença. OBJETIVOS: Avaliação da resposta terapêutica à fotoquimioterapia PUVA em pacientes com micose fungóide. MÉTODOS: Entre janeiro de 1996 e novembro de 2003 avaliaram-se 17 pacientes com micose fungóide no setor de Fototerapia da Clínica Dermatológica da Santa Casa de São Paulo. A terapia com PUVA foi realizada como monoterapia nos estádios iniciais ou como coadjuvante nos estádios avançados da doença. Avaliou-se o resultado do tratamento quanto ao aspecto clínico das lesões e parâmetros histológicos após tratamento. RESULTADOS: Quatorze de 16 pacientes responderam à fotoquimioterapia. Relacionando o estadiamento da doença à resposta terapêutica obteve-se o seguinte: cinco pacientes (um em estágio IA e quatro em IB) com controle total (cura das lesões); quatro (todos IB) com melhora intensa (controle de 70-99%); dois (IIB e IVA) com melhora moderada (de 50 a 69%); três (IA, IB, IIA) com melhora discreta (menos 50%); dois (IB, IIB) inalterados (sem resposta). Um paciente teve de descontinuar o tratamento por apresentar intenso ardor. CONCLUSÃO: Houve resposta à terapia PUVA em 87% dos pacientes, com controle total ou melhora intensa da doença em 56% dos casos. Sua efetividade permitiu regressão das lesões cutâneas, principalmente nos casos precoces. A fotoquimioterapia com PUVA mostrou ser tratamento seguro e efetivo, devendo ser considerado em pacientes com micose fungóide.

Extracorporeal photopheresis affects interleukin (IL)-10 and IL-12 production by monocytes in patients with chronic graft-versus-host disease

BACKGROUND

Chronic graft-versus-host disease (cGVHD) is a major complication of allogeneic bone marrow transplantation. Extracorporeal photopheresis (ECP) has recently been introduced as an alternative treatment for cases of cGVHD refractory to conventional immunosuppressive treatment, but its mechanism of action is not yet clear.

OBJECTIVES

To investigate in seven patients with cGVHD the effects of ECP on resistance of monocytes to apoptosis and on monocyte cytokine production.

METHODS

We designed an in vitro model that could mimic the potential in vivo effect of reinfusion of peripheral blood mononuclear cells treated by ECP. The model was based on coculture of ECP-treated lymphocytes with untreated monocytes from the same patient.

RESULTS

ECP did not accelerate spontaneous apoptosis of monocytes. However, ECP-treated monocytes produced increased amounts of interleukin (IL)-12. In contrast, IL-12 production by monocytes did not increase in cocultures, but IL-10 production was upregulated.

CONCLUSIONS

These results suggest that reinfusion of large numbers of autologous apoptotic lymphocytes is significant for the therapeutic outcome of ECP through upregulation of IL-10, which is an immunosuppressive cytokine.

The treatment of cutaneous T-cell lymphoma with photopheresis

Photopheresis or extracorporeal photochemotherapy (ECP) is an immunomodulating procedure that has been available for the treatment of cutaneous T-cell lymphoma (CTCL) since 1987. A concentrated white blood cell (WBC) sample spiked with 8-methoxypsoralen (methoxsalen) is exposed to an ultraviolet A light source, then all blood components are returned to the patient. Treatment of mycosis fungoides (MF) and Sézary syndrome (SS) with ECP has been reported in over 400 patients. The combined overall response rate for all stages of CTCL is 55.7% (244 out of 438) with 17.6% (77 out of 438) achieving a complete response. Efficacy in treating certain clinical stages (IB, IIA, III and IVA) and skin stages (T2 and T4) of MF and SS is favorable, although randomized trials comparing ECP to other standard therapies are needed. The use of ECP to treat early stage patients remains controversial. Efforts to establish the effectiveness of combining ECP with other newer immunoadjuvant therapies and modifications of the procedure to enhance immunomodulation are exciting prospects for patients with CTCL.