Treatment of peripheral blood mononuclear cells with 8-methoxypsoralen plus ultraviolet A radiation induces a shift in cytokine expression from a Th1 to a Th2 response

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.

Exogenous melatonin modulates carbon ion radiation-induced immune dysfunction in mice

In spite of carbon ion radiotherapy is a talented modality for malignant tumor patients, the radiation damage of normal tissues adjacent to tumor and the dysfunction of immune system limits therapeutic gain. Protecting immune system against carbon ion radiation-caused damage has the possibility to improve cancer treatment, but it is uncertain whether conventional radioprotective agents play a role in carbon ion radiation. To certify carbon ion caused immune dysfunction and assess the radioprotective effect of melatonin on immune system, animal experiments were performed in radiosensitive BALB/C mice. Here, we observed the bodyweight loss, death and apoptosis, abnormal T-cell distributions in immune system in carbon ion radiated mice. Pretreatment with melatonin could increase the index of thymus and spleen, reduce cell apoptosis in thymus and spleen, and attenuate the carbon ion radiation-caused imbalance of T lymphocytes and disorder of cytokines. These results suggest that melatonin can act as an effective protector against carbon ion radiation-caused immune dysfunction. Furthermore, we also found melatonin restored the activity of the antioxidant enzymes and reduced the level of lipid peroxidation in serum. These data have provided baseline information both for radiation workers and cancer patients to use melatonin as a radioprotector during the carbon ion radiation treatment.

Depleting the carboxy-terminus of human Wnt5a attenuates collagen-induced arthritis in DBA/1 mice

Wnt5a signalling plays pathological roles in synovial inflammation and bone destruction. In the present study, we designed four human Wnt5a-based DNA recombinants and detected their effects on immunogenicity and anti-rheumatism in a collagen-induced arthritis (CIA) model. Histomorphometry and micro-CT scanning showed that the phWnt5a-NL was superior to other recombinants because it resulted in decreased severity of arthritis, histopathological scores of synovial inflammation and bone erosion in CIA mice. In addition, ELISA and TRAP staining showed that the phWnt5a-NL-immunized CIA mice had reductions in the serum concentrations of the rheumatoid-associated cytokines IL-1β and RANKL and in osteoclastogenesis. Furthermore, flow cytometry showed that the phWnt5a-NL treatment increased the percentage of Treg cells. Finally, western blotting analysis showed that the phWnt5a-NL-immunization interrupted β-catenin and JNK expression in osteoclast precursors derived from the CIA mice. The results suggest that depleting the carboxy-terminus in hWnt5a-based DNA recombinants may be beneficial for the treatment of chronic inflammatory disorders involving bone resorption.

Indication-specific immunomodulatory effects of extracorporeal photopheresis: A pilot study in heart transplanted patients

BACKGROUND

The clinical use of extracorporeal photopheresis (ECP) is based on its ability to induce cell-mediated immune tolerance towards foreign and self-antigens. Up-to-date, no clear consensus consists on how to use ECP after heart transplantation (HTx). In this pilot study, we evaluated the stimulatory effects of ECP on immune cells in HTx patients.

METHODS

HTx patients received ECP therapy as prophylaxis of rejection (PRX, n = 15), to treat acute cellular rejection (ACR, n = 13) or cardiac allograft vasculopathy (CAV, n = 5). Three ECP cycles with monthly frequency were performed. Blood samples were taken before every ECP cycle and 2 months after the last ECP cycle and were analyzed for cytokines and the tolerance-inducing cell subsets regulatory T cells (T_regs ), myeloid (mDCs), and plasmacytoid dendritic cells (pDCs).

RESULTS

While ECP treatment induced first an increase of pDCs in the CAV group (baseline: 22.0% ± 9.6%, prior third ECP cycle: 8.6% ± 3.2%, follow-up: 31.5% ± 8.4%, P = .009), no significant changes of DC subsets and T_regs were observed in the ACR- and in the PRX group. Furthermore, analysis of the immune balance showed different response profiles of pro- and anti-inflammatory cytokines among prophylactically ECP-treated patients and ECP-treated patients suffering from CAV or ACR.

CONCLUSIONS

In our pilot study, we showed different stimulatory effects of ECP on pDCs and cytokines among prophylactic and therapeutic ECP therapy after HTx. Immunological monitoring should be included in a larger clinical study of ECP treatment following HTx and to identify predictable parameters for ECP efficacy.

Extracorporeal photopheresis after heart transplantation

The addition of extracorporeal photopheresis (ECP) to a standard immunosuppressive drug therapy after heart transplantation in clinical studies has shown to be beneficial, for example, by reducing acute rejection, allograft vasculopathy or CMV infection. However, the protocols varied considerably, have a predetermined finite number of ECP treatments and adjuvant immunosuppressive regimens used in combination with ECP have differed significantly. Furthermore, there are scarce data to guide which patients should be treated with ECP and when or who would benefit further if ECP were to be continued long term to increase the safety by reducing immunosuppressive drug toxicities without losing efficacy. The knowledge of the tolerance-inducing effects of ECP-like upregulation of regulatory T cells and of dendritic cells may allow to develop a strategy to monitor immunomodulation effects of ECP to further identify ECP responders, the optimal individual ECP schedule and whether ECP therapy can replace or reduce immunosuppressive drug therapy.

Extracorporeal photopheresis as a therapy for autoimmune diseases

Systemic autoimmune diseases (AID) have multiorgan, heterogeneous clinical presentations and are characterized by dysregulation of the immune system, immunodeficiency, irreversible organ damage and increased morbidity and mortality. Preventing or decreasing flares of AID correlate with durable disease control, significant reduction of inflammation and prevention of disability or therapy-related toxicity. There is an urgent need for better treatment of severe, therapy-refractory AID. Extracorporeal photopheresis (ECP) is a cell-based immunomodulatory treatment which has been extensively used in variety of autoimmune disorders for the last two decades. ECP treatment is FDA approved for the treatment of cutaneous T-cell lymphoma (CTCL) with particularly promising results seen in graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HCT). Prolonged therapy is safe, well tolerated and allows reduction of systemic immunosuppression in therapy-refractory patients. Both clinical and experimental evidence suggest that ECP mechanism of action is characterized by apoptosis and phagocytosis of activated cells by antigen-presenting cells (APC), secretion of anti-inflammatory cytokines and stimulation of regulatory T cells (Tregs). The focus of this paper is to review the current evidence of ECP use in the treatment of AID. Here, we summarize the experience of nine major AID from 65 published reports. The key findings demonstrate substantial evidence of ECP feasibility, safety and in some AID also promising efficacy. However, the role of ECP in AID therapy is not established as most published studies are retrospective with limited number of patients and the trials are small or poorly standardized. The available data support future investigations of ECP as a therapeutic modality for the treatment of AID in well-designed prospective clinical studies. J

Serum levels of LL-37 and inflammatory cytokines in plaque and guttate psoriasis

Psoriasis is a chronic inflammatory skin disease. It is assumed that the plaque phenotype of psoriasis is associated with T helper (Th) 1 immune response activation, while the guttate phenotype is associated with the Th17 immune response. Previous investigations of differences in the serum levels of cytokines relative to the clinical psoriatic phenotype have yielded conflicting results. This study compared the levels of circulating inflammatory cytokines and LL-37 relative to the morphological phenotype in patients with psoriasis. Seventy-four age-matched patients with psoriasis (32 with guttate psoriasis and 42 with plaque psoriasis) and 12 healthy controls were included. A multiplex cytokine assay and enzyme-linked immunosorbent assay were used to measure levels of Th1- and Th17-derived cytokines and LL-37, respectively. Circulating levels of interferon- (IFN)-γ, interleukin- (IL)-1RA, IL-2, and IL-23, and LL-37 were significantly higher in patients with psoriasis than in healthy controls. However, the serum levels of inflammatory cytokines (IL-7, IL-22, and IL-23) and LL-37 did not differ significantly between the guttate and plaque phenotypes of psoriasis. There was a positive correlation between serum inflammatory cytokine levels and the Psoriasis Area and Severity Index score. The findings of this study suggest that the serum levels of inflammatory cytokines reflect the disease activity rather than determine the morphological phenotype.

Protective effect of hydrogen-rich saline against radiation-induced immune dysfunction

Recent studies showed that hydrogen can be used as an effective radioprotective agent through scavenging free radicals. This study was undertaken to evaluate the radioprotective effects of hydrogen on immune system in mice. H₂ was dissolved in physiological saline using an apparatus produced by our department. Spleen index and histological analysis were used to evaluate the splenic structural damage. Spleen superoxide dismutase, GSH, MDA were measured to appraise the antioxidant capacity and a DCF assay for the measurement of radical oxygen species. Cell apoptosis was evaluated by an Annexin V-FITC and propidium iodide staining method as well as the apoptotic proteins such as Bcl-2, Bax, caspase-3 and c-caspase-3. CD4+ and CD8+ T cells subtypes were detected by flow cytometry with FITC-labelled antimouse CD4 and PE antimouse CD8 staining. Real-time PCR was utilized to determine the CD4+ T cell subtypes and related cytokines. Our study demonstrated that pre-treatment with H₂ could increase the spleen index and attenuate the radiation damage on splenic structure. Radical oxygen species level was also reduced by H₂ treatment. H₂ also inhibited radiation-induced apoptosis in splenocytes and down-regulated pro-apoptotic proteins in living mice. Radiation-induced imbalance of T cells was attenuated by H₂. Finally, we found that H₂ could regulate the polarization of CD4+ T cells and the level of related cytokines. This study suggests H₂ as an effective radioprotective agent on immune system by scavenging reactive oxygen species.

The roles of cells and cytokines in the pathogenesis of psoriasis

Psoriasis is considered an immune chronic disease in which T cells are accepted as important. Nowadays, it is believed that psoriasis is most likely a T helper (Th)1/Th17 induced inflammatory disease. However, some other cells, such as endothelial cells, dendritic cells, monocytic cells, neutrophils, keratinocytes, and several cytokines, appear to have, at different stages of the disease, an important role in its pathogenesis. For instance, the response to psoriasis therapy is dependent not only on the inactivation of Th1 and Th17 immune responses but also on the inactivation of dendritic cell products. Moreover, interleukin (IL)-23 deregulation appears to be an independent factor in the pathogenesis of psoriasis. Indeed, currently, the IL-23/Th17 axis is believed to be crucial in psoriasis pathogenesis, and its inhibition appears to be important for therapeutic achievement. This review presents the roles and interactions of cells and cytokines that are related to psoriasis pathogenesis.

Pruritus in cutaneous T-cell lymphoma: a review

BACKGROUND

Pruritus can be a distressing and even debilitating symptom for patients with cutaneous T-cell lymphoma (CTCL). To date, few studies have evaluated the pathophysiology of this symptom. Because of this, therapy for pruritus in CTCL has mainly relied on those therapies that target and treat the lymphoma. For patients living with CTCL that relapses or becomes refractory to treatment, and who continue to experience severe itch, this lymphoma-targeted treatment may not be enough to combat their pruritus. Therefore, other itch-targeted therapies are needed for use in this disease.

OBJECTIVE

We sought to evaluate the current evidence regarding the mechanism of action and treatments for pruritus associated with CTCL.

METHODS

An explicit and thorough search was restricted to all peer-reviewed literature available through MEDLINE (1950 to September 2011) and PubMed. Search terms used were "pruritus," "cutaneous T-cell lymphoma," "CTCL," "mycosis fungoides," "MF," and "Sézary syndrome." All studies that involved pruritus in CTCL, mycosis fungoides, or Sézary syndrome were evaluated by all 3 authors.

RESULTS

The current literature helps to identify therapies and possible mechanisms for treating patients with CTCL-associated pruritus.

LIMITATION

Most studies were preclinical. Only studies involving mechanisms of action or treatment were included.

CONCLUSION

A guideline is necessary to assist in the treatment of pruritus in CTCL and additional studies are necessary to uncover the exact mechanism or mechanisms of action.

Predictors of response to extracorporeal photopheresis in advanced mycosis fungoides and Sézary syndrome

BACKGROUND

Extracorporeal photopheresis (ECP) has been utilized for more than 20 years to treat cutaneous T-cell lymphoma (CTCL), but a clinical response can take up to 9 months to manifest. This study was undertaken to determine whether clinical features, laboratory values, cytokine levels, or gene expression levels of tumor markers are useful to predict the subsequent response to ECP in CTCL patients with blood involvement.

METHODS

Twenty-one patients with CTCL treated with ECP as monotherapy for at least 6 months were retrospectively identified. Laboratory and clinical data and blood obtained at baseline, 3, and 6 months of treatment were used for analysis.

RESULTS

In pretreatment blood specimens, a lower percentage of Sézary cells and a higher absolute eosinophil count were associated with a favorable clinical response. Clinical evidence of an early response after 3 months of ECP did not reliably predict a favorable response at 6 months or beyond. Comparison of cytokines, gene transcripts, and other laboratory measures of disease did not correlate with the subsequent clinical response, although lactate dehydrogenase levels tended to decrease progressively in ECP-responsive cases and increase progressively in ECP-non-responsive cases. Additionally, serum levels of TNF-alpha significantly increased from baseline to 6 months of ECP, but was not found to correlate with the clinical response.

CONCLUSIONS

Although we found that increased eosinophils and decreased percentage of Sézary cells were associated with a favorable clinical response to ECP, we were not able to identify the predictors of ECP response within the first 3 months of treatment.

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.

Extracorporeal photochemotherapy (ECP) in treatment of patients with c-GVHD and CTCL

We evaluated the immunomodulatory and clinical effect of 279 extracorporeal photochemotherapy (ECP) procedures which were performed in six patients with chronic extensive GVHD and in two patients with CTCL (cutaneous T-cell lymphoma)/Mycosis fungoides. ECP was performed using the off line regimen. In five of six patients with c-GVHD the improvement of sclerodermatous skin changes, joint mobility, and the reduction of joint pain was observed. Two patients with CTCL responded to ECP with rapid improvement of the skin changes. In patients with c-GVHD and CTCL who responded to ECP efficiently, we found the similar tendency to increase in the number of CD 3/8+ T-lymphocytes and the decrease of CD 4/8 IRI. In patients with CTCL we observed also the decrease in levels of CD 3/4+ T-lymphocytes and in the number of leukocytes. The influence of ECP on T-cell subsets and on the dendritic cells function, which we observed in our previous study, leads to the suggestion that interactions between T-cell subsets and dendritic cells may participate in the process of ECP. ECP did not cause any significant changes in levels of IgG, parameters of liver and renal functions in patients with c-GVHD and with CTCL. No increased incidence of infections and no serious adverse reactions in patients have been observed so far.

Photodegradation of folic acid during extracorporeal photopheresis

BACKGROUND

Photodegradation of folic acid (FA) by ultraviolet (UV) radiation is a well-documented photochemical reaction, and decreased serum levels of FA have been found in patients receiving photochemotherapy (psoralen plus UVA). During extracorporeal photopheresis (ECP) leucocytes and plasma are subjected to 8-methoxypsoralen (8-MOP) plus UVA.

OBJECTIVES

To investigate whether ECP leads to the photodegradation of FA in the extracorporeal system.

METHODS

In 30 patients undergoing ECP on two consecutive days the FA levels were measured in the extracorporeal collected plasma prior to and after UVA exposure. Healthy donor plasma was exposed to 8-MOP and increasing doses of UVA in vitro. In five patients serum folate levels were determined before and after ECP.

RESULTS

We found a mean reduction of 44% and 46% on the first and second day of treatment, respectively. This effect could be reproduced in vitro: the irradiation of healthy donor plasma with UVA led to a dose-dependent reduction of FA of up to 54.75% at 16 J cm(-2). This was independent of the presence of 8-MOP and the base concentration of 5-methyltetrahydrofolate; minimal changes were observed for vitamin B(12) and homocysteine, not undergoing photodegradation. Serum folate levels did not change significantly before and after ECP.

CONCLUSIONS

We conclude that extracorporeal exposure of plasma to UVA during ECP leads to photodegradation of FA. Further investigations are required to determine the biological effects of folate photoproducts and whether clinically relevant loss of FA might be a consequence of ECP.

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.

The down-regulation of IL1alpha and IL6, in monocytes exposed to extracorporeal photopheresis (ECP)-treated lymphocytes, is not dependent on lymphocyte phosphatidylserine externalization

Extracorporeal photopheresis (ECP) has been successfully used to treat some inflammatory conditions. Following ECP, lymphocytes become apoptotic and untreated monocytes, exposed to post-ECP lymphocytes, reduce proinflammatory cytokine secretion. This study attempted to establish if this monocyte immunosuppression was linked to phosphatidylserine externalization (detected using Annexin V) on the apoptotic lymphocytes. Using density gradient and magnetic separation, lymphocytes were isolated from three cutaneous T-cell lymphoma and nine chronic graft versus host disease (cGvHD) patients pre-ECP and prior to re-infusion (post-ECP). The collected lymphocytes were cultured overnight and Annexin V levels determined. Peripheral blood was taken from the same patient 20 h later and the monocytes were isolated. The 'fresh' monocytes were introduced to each 20 h pre- and post-ECP lymphocyte culture, stimulated with lipopolysaccharide (LPS) and Brefeldin A and subsequently tested for intracellular tumour necrosis factor alpha, interleukin 1 alpha (IL1alpha), IL1beta, IL6 and IL8. For cGvHD patients, the relative levels of IL1alpha and IL6 were reduced in the untreated, LPS-stimulated monocytes exposed to post-ECP lymphocytes. However, the down-regulation of IL1alpha and IL6 did not correlate to levels of Annexin V-positive lymphocytes. ECP-treated lymphocytes can reduce the ability of LPS-stimulated monocytes to produce some proinflammatory cytokines; however, this effect is not dependent on phosphatidylserine externalization.

Lymphocytes treated by extracorporeal photopheresis can down-regulate cytokine production in untreated monocytes

BACKGROUND

Pro-inflammatory cytokines are actively involved in graft-versus host-disease (GvHD) aetiology. Treatment of GvHD, using extracorporeal photopheresis (ECP), has demonstrated clinical efficacy. ECP rapidly reduces the number of T cells that produce tumour necrosis factor alpha (TNFalpha), interferon gamma (IFNgamma) and interleukin (IL)2. ECP-treated cells are re-infused immediately after completion of treatment. This study attempted to determine the influence that ECP-treated cells would have on untreated cells following re-infusion.

METHODS

Heparinized samples were taken from 10 chronic GvHD patients, pre-ECP and immediately prior to re-infusion (post-ECP). Lymphocytes and monocytes were isolated using magnetic separation. The post-ECP lymphocytes were mixed with pre-ECP monocytes, while the post-ECP monocytes and pre-ECP lymphocytes were combined. After suitable stimulation, the T cells were tested for intracellular TNFalpha, IFNgamma and IL2, while the monocytes were evaluated for TNFalpha, IL1alpha, IL1beta, IL6 and IL8.

RESULTS

Although cytokine secretion is decreased in T cells exposed to ECP, pre-ECP T cells were unaffected by post-ECP monocytes. Post-ECP monocytes demonstrated a reduction in cytokine secretion. Furthermore, untreated monocytes down-regulated cytokine production following exposure to ECP-treated lymphocytes.

CONCLUSION

ECP has both a direct and indirect immunosuppressive action, both of which may be beneficial in the treatment of GvHD.

Evidence-based practice of photopheresis 1987-2001: a report of a workshop of the British Photodermatology Group and the U.K. Skin Lymphoma Group

Photopheresis or extracorporeal photochemotherapy (ECP) is a novel immunomodulatory therapy which involves separation of the patient's leucocyte-rich plasma, followed by ex vivo administration of a photosensitizer and ultraviolet A radiation, before reinfusion. ECP has been used successfully for the treatment of cutaneous T-cell lymphoma (CTCL: Sézary syndrome), graft-versus-host disease (GVHD) and cardiac transplant rejection. ECP has a dose-sparing effect on concurrent immunosuppressive therapy. The procedure induces apoptosis of the irradiated lymphocytes, but the exact mechanism by which ECP exerts its therapeutic effect in these different conditions is uncertain. The treatment has very few adverse effects and in particular is not associated with an increased incidence of opportunistic infections. The evidence for the efficacy of ECP has been appraised by a combined British Photodermatology Group and U.K. Skin Lymphoma Group workshop on the basis of evidence published up to the end of 2001 and on the consensus of best practice. There is fair evidence for the use of ECP in erythrodermic CTCL and steroid-refractory GVHD, but randomized controlled studies are needed. There is good evidence supporting the use of ECP in preventing cardiac rejection following transplantation. Randomized controlled trials have also shown a therapeutic benefit in type 1 diabetes mellitus, but the inconvenience associated with the procedure outweighed the clinical benefit. There is fair evidence not to use ECP for the treatment of systemic sclerosis and multiple sclerosis, and good evidence not to use ECP for other forms of CTCL.

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.

Vitamin D receptor gene polymorphisms, particularly the novel A-1012G promoter polymorphism, are associated with vitamin D3 responsiveness and non-familial susceptibility in psoriasis

Psoriasis is a genetically determined disease characterized by hyperproliferation and disordered maturation of the epidermis. Th1 lymphocytes are implicated in its pathogenesis. The vitamin D receptor (VDR) is a candidate modifying gene, having immunosuppressive effects and being involved in anti-proliferative and pro-differentiation pathways in keratinocytes. There is suggestive evidence that the A allele of the A-1012G polymorphism is associated with down-regulation of the Th1 response, via GATA-3. The F and T alleles of Fok1 and Taq1 have been associated with increased VDR activity. The present study aimed to test the hypothesis that the A allele of A-1012G is protective for occurrence and severity of psoriasis and enhances therapeutic response to vitamin D analogues and that these effects would be additive to those of Fok1 and Taq1. The study group comprised 206 psoriasis patients who had received topical calcipotriol treatment and 80 controls. There was no significant linkage disequilibrium between any pair of the three polymorphic sites (P=0.3-0.8). The A, F and T alleles were positively associated with calcipotriol response: AA genotype (compared to AG/GG), odds ratio (OR)=2.18 (P=0.04); TT, OR=1.97 (P=0.03); AAFF genotype combination, OR=4.11 (P=0.03); AATT, OR=5.64 (P=0.005); and FFTT, OR=3.22 (P=0.01). Comparing patients without, to patients with, a family history of psoriasis, the A allele was under represented (P=0.01) and the AAFF genotype combination even more so (compared to residual genotypes) (OR=0.24; P=0.005). AAFF was also under-represented in patients without a family history compared to controls (OR=0.31; P=0.04). There were no associations of family history with Fok1 and Taq1. There were no associations of severity of psoriasis with any polymorphism. In conclusion, the A-1012G, Fok1 and Taq1 VDR polymorphisms were associated with response to calcipotriol. A-1012G and Fok1 were associated with susceptibility to non-familial psoriasis.

Extracorporeal Photopheresis Differentially Regulates the Expression of Phosphorylated STAT-1 and STAT-5 in Treated Monocytes and T cells, Respectively

BACKGROUND

Extracorporeal photopheresis (ECP) is effective in conditions with opposing immune etiology. ECP induces an immunomodulatory response through simultaneous monocyte activation and apoptosis induction of lymphocytes. However, ECP is also immunosuppressive, downregulating proinflammatory cytokines. Signal transducers and activators of transcription (STATs) are important mediators of cell-signaling systems, including cytokines. Ultraviolet (UV) immunosuppression is linked to reductions in cytokine-induced STAT phosphorylation.

OBJECTIVE

The aim of this study was to find whether ECP downregulates STAT phosphorylation.

METHODS

Pre- and post-ECP mononuclear cells from cutaneous T-cell lymphoma and chronic graft-versus-host disease patients were stimulated with either IFNbeta, IL2, or IL15. The percentage of IFNbeta-stimulated monocytes positive for phosphorylated STAT-1 (pSTAT-1) and the number of IL2- and IL15-stimulated T cells expressing phosphorylated STAT-5 (pSTAT-5) were determined at 0 and 24 h.

RESULTS

Post-ECP, pSTAT-1 levels in monocytes remained unchanged; however, at 24 h post-ECP the number of T cells expressing pSTAT-5 was reduced.

CONCLUSION

Following ECP, monocytes retain their ability to phosphorylate STAT-1, while pSTAT-5 expression is lost in lymphocytes. This differential effect of ECP may account for the diverse population of diseases that benefit.

Effect of photopheresis on lymphocyte population in children with newly diagnosed type 1 diabetes

In recent years photopheresis has been claimed to be an effective form of immunomodulation. It has also been shown to have an effect on the disease process at the onset of type 1 diabetes. In a double-blind, placebo-controlled randomized study, we analyzed if the effect of photopheresis in children with newly diagnosed diabetes is related to changes in the balance of lymhocyte populations. We also analyzed if lymphocyte subsets were related to recent infection, mild or aggressive disease manifestations, heredity, or gender. Nineteen children received active treatment with photopheresis, while 21 children received sham pheresis (placebo group). No influence of a history of previous infection, heredity, or certain clinical parameters on lymphocyte subsets was found. At the onset of type 1 diabetes, girls showed a higher proportion and a larger number of T cells (CD3+) and T-helper cells (CD4+) and a higher proportion of naïve CD4+ CD45RA+ cells. In the placebo group, an increase in the number of subsets with the activated phenotype in both the CD4(CD29+) and the CD8 (CD11a+) compartments was noted during the course of the study. These changes did not occur in the photopheresis group. No relation between lymphocyte subsets and clinical outcome was found 1 year after the treatment with photopheresis. In conclusion, we found no major effect of photopheresis on lymphocyte populations in a group of children with newly diagnosed type 1 diabetes. However, in the placebo group the proportions of activated CD4 and CD8 cells increased over time. Since these changes did not occur in the actively treated group, our findings suggest that photopheresis may have some suppressive effects.

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

Chronic graft-versus-host disease (GvHD) affects 50% of long-term bone marrow transplant survivors and remains a cause of major long-term morbidity in these patients despite aggressive therapy. Extracorporeal photochemotherapy (ECP), considered as an effective treatment for patients with erythrodermic cutaneous T-cell lymphoma (CTCL), has recently been used successfully in the treatment of GvHD. One of the most intriguing aspects of ECP is its ability to induce two apparently opposite effects: activation of the immune system against neoplastic cells (as in CTCL) and downregulation of the activity of T-cell clones in autoimmune diseases (as in systemic sclerosis, systemic lupus erythematosus and pemphigus vulgaris) and autoallogeneic immune responses (as in GvHD and allograft rejection). Only a better and more complete understanding of the various mechanisms involved will enable this interesting new therapy to be made more effective and selective.

The effect of extracorporeal photopheresis on intracellular cytokine expression in chronic cutaneous graft-versus-host disease

BACKGROUND

Cytokines derived from T helper (Th)1 lymphocytes are thought to be involved in the pathogenesis of graft-versus-host disease (GVHD) and extracorporeal photopheresis (ECP) has been reported to affect Th1/Th2 lymphocyte ratios. It may also influence the balance of cytotoxic Tcells (Tc1/Tc2).

OBJECTIVES

This study was formulated to assess the effect of ECP on the cytokine profiles of peripheral blood (PB) lymphocytes from patients with chronic GVHD.

PATIENTS AND METHODS

Nine patients were studied. Peripheral blood was sampled at baseline and between 3 and 4 months of therapy when clinical effects are demonstrable. Intracellular cytokine production was assessed in vitro by stimulating PB lymphocytes with phorbol-12-myristate 13-acetate (PMA), inhibiting cytokine release and staining with fluorescein-labelled monoclonal antibodies to interleukin (IL)-2, interferon gamma (IFN-gamma) and IL-4. Flow cytometry analysis gave the absolute number and the percentage of cells expressing a particular cytokine within each lymphocyte subset.

RESULTS

Absolute counts of CD3, CD4, CD8, CD19 and CD16+ cells per microlitre were recorded before and after ECP. There was a small but non-significant reduction in all subsets after 3 months of ECP. The percentage of cells expressing IL-2 and IFN-gamma rose following ECP in both the CD4 and CD8 subsets. However, only the percentage of CD4 cells expressing IFN-gamma reached statistical significance (P = 0.02; 95% confidence interval, CI 0.6-15.6). There were no significant changes in the percentage of CD4 cells expressing IL-4.

CONCLUSIONS

Our findings appear to be inconsistent with current theories regarding the pathogenesis of GVHD as increased production of Th1 or Tc1 cytokines might be expected to exacerbate GVHD. However, chronic GVHD is characterized by a relative deficiency of IL-2 and IFN-gamma producing cells compared with other patients post-bone marrow transplantation (BMT). This indicates that Th1 and Tc1 cytokines are depleted in chronic GVHD. Thus, by reducing disease activity, ECP could allow cytokine production by these cells to recover. This indicates that the therapeutic effect of ECP is mediated by a different mechanism, and that the changes observed in this study are epiphenomena.

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.

Chromatographic determination of the association constant between 8-methoxypsoralen and modified β-cyclodextrin: protective effect of hydroxypropyl-β-cyclodextrin on 8-methoxypsoralen toxicity in human keratinocytes

The retention of 8-methoxypsoralen (8-MOP) on an immobilised hydroxypropyl-beta-cyclodextrin (HP-beta-CD) column was analysed in HPLC by the determination of its Langmuir distribution isotherm. A such method was used to confirm the potential drug complexing role of this cyclodextrin. The 8-MOP/HP-beta-CD association constant (K) was equal to 29.5 and 18.7 M-1, respectively, at a temperature equal to 5 and 25 degrees C, respectively. These association constant values were used to determine the cytotoxicity profile of human keratinocyte cell line (HaCaT) in relation to the complex concentration. It was showed through these data that HP-beta-CD had a cytoprotective since a reverse effect of HP-beta-CD on 8-MOP cytotoxicity was observed.

Extracorporeal photopheresis reduces the number of mononuclear cells that produce pro-inflammatory cytokines, when tested ex-vivo

Extracorporeal photopheresis (ECP) has been shown to be clinically effective in the treatment of many T cell-mediated conditions. ECP's mechanism of action includes the induction of apoptosis and the release of pro-inflammatory cytokines. Recently, we have observed early lymphoid apoptosis, detectable immediately post ECP. We were interested to determine what influence ECP has on pro-inflammatory cytokine secretion at this early pre-infusion stage. Samples from 6 cutaneous T cell lymphoma (CTCL) and 5 graft versus host disease (GvHD) patients were taken pre ECP and immediately post ECP, prior to re-infusion. Following separation, the PBMCs were added to a cell culture medium and stimulated with PMA, Ionomycin, and Brefeldin A for 6 hours. Using flow cytometry, intracellular cytokine expression of IFNgamma and TNFalpha was determined in the T cell population. The monocytes were evaluated for IL6, IFNgamma, IL12, and TNFalpha. For both patient groups, the number of IFNgamma-expressing T cells fell significantly at re-infusion, whilst both T cell- and monocyte-expressing TNFalpha levels were reduced at re-infusion. All other cytokines tested showed no significant change post ECP. For GvHD, pro-inflammatory cytokines have a pathological role. Their down-regulation may have a direct clinical benefit. However, the reduction in the number of IFNgamma- and TNFalpha-expressing mononuclear cells means, at this early stage, it is unlikely that these cytokines assist in the removal of the malignant Th2 cells present in CTCL.

Early reduction in number of T cells producing proinflammatory cytokines, observed after extracorporeal photopheresis, is not linked to apoptosis induction

Immediately following ECP, a significant number of lymphocytes become apoptotic and the number of T cells producing TNFalpha and IFNgamma is reduced. This study sought to determine if the cytokine down-regulation was a direct consequence of apoptosis induction.

METHODS

Samples were obtained from 6 graft versus host disease (GvHD) and 5 cutaneous T cell lymphoma (CTCL) patients immediately pre-ECP and from the leucocyte collection bag following 8-MOP/UVA exposure, but prior to re-infusion. Separated peripheral blood mononuclear cells (PBMC) were placed in cell culture and stimulated for 6 hours with phorbol myristate acetate (PMA), Ionomycin and Brefeldin A. Using flow cytometry, T cells were identified by CD3 expression and apoptotic T cells sub-selected by Annexin V staining. Both apoptotic and non-apoptotic T cells were evaluated for their intracellular expression of IL2, IL4, IL10, IFNgamma and TNFalpha.

RESULTS

Neither patient group demonstrated a significant change in IL4 or IL10 expression post ECP. However the number of T cells expressing IL2, IFNgamma and TNFalpha was reduced in both the Annexin V-positive and -negative T cell populations (P <.05). The nonapoptotic T cells from GvHD patients demonstrated the greatest reduction in cytokine expression.

CONCLUSIONS

Since proinflammatory cytokines play a major role in the pathology of GvHD, their down-regulation post-ECP may produce a direct clinical benefit. The lowest number of IL2-, IFNgamma- and TNFalpha-expressing T cells occurred within the apoptotic population; however, Annexin V-negative T cells also demonstrated a marked reduction post-ECP. However, the lack of an increase in IL4 and IL10 expression indicates that this process was not a consequence of skewing toward a Th2 cytokine profile.

Extracorporeal photopheresis therapy in the management of steroid-refractory or steroid-dependent cutaneous chronic graft-versus-host disease after allogeneic stem cell transplantation: feasibility and results

We conducted a retrospective analysis of all allogeneic stem cell transplantation (ASCT) patients started on extracorporeal photopheresis (ECP) for the management of steroid-dependent (SD) or steroid-refractory (SR) cutaneous chronic graft-versus-host disease (cGVHD) following ASCT during a 36-month period (9/98-8/01). Only SD or SR patients who were treated by ECP after day 100 and who received at least 4 weeks of ECP were considered evaluable for this analysis. Out of 64 ASCT patients reviewed, 32 patients met the inclusion criteria. All 32 patients had been previously treated with systemic corticosteroids with 11 (34%) being SR and 21 (66%) SD. Cutaneous cGVHD was extensive in 28 patients (88%) and was accompanied by visceral (hepatic, gastrointestinal) cGVHD in 23 patients (72%). The 32 evaluated patients had received a median of three prior therapies before ECP, most commonly systemic corticosteroids, tacrolimus, and mycophenolate mofetil. Patients received a median of 36 ECP sessions (range 12-98) over a median of 5.3 months (range 1-28), with a median of six sessions per month. The complete response (CR) rate was 22% (n=7) and the partial response rate was 34% (n=11). In all, 28 patients were on systemic corticosteroid therapy at ECP initiation and 18 patients achieved 50% dose reduction while on ECP, yielding a 64% steroid-sparing response rate. Of seven CRs, five are ongoing. A total of 11 (34%) patients have died after ECP, with all cases due to visceral cGVHD or cGVHD-related infectious complications. All 21 surviving patients remain on at least some immunosuppressive cGVHD therapy (including ECP in eight). Overall, ECP displays a substantial response rate and, in particular, steroid-sparing activity in SR/SD extensive cutaneous cGVHD. However, most patients continue to require at least some chronic therapy and cGVHD-related morbidity and mortality remain high.

Treatment of cutaneous T cell lymphoma with extracorporeal photopheresis induces Fas-ligand expression on treated T cells, but does not suppress the expression of co-stimulatory molecules on monocytes

Following extracorporeal photopheresis (ECP), lymphocytes become apoptotic and upregulate class I MHC antigenic peptides. Conversely, ECP treated monocytes demonstrate activation markers and have an increased avidity for the phagocytosis of apoptotic T cells. Processing of apoptotic T cells by monocytes, following ECP, is thought to induce an immunomodulatory response, which targets untreated, but clonal T cells. Recently we detected apoptotic lymphocytes immediately post ECP. Although enhanced CD95 (Fas) expression has been observed 24 h post ECP, CD95 and Fas-ligand (Fas-L) expression have not been determined at this very early apoptotic stage. Exposure of monocytes to UV has previously suppressed expression of the co-stimulatory molecules required for the presentation of processed antigens to T cells. Our data demonstrate no increase in CD95 or Fas-L expression on T cells tested immediately following ECP. However, the number of T cells expressing Fas-L significantly increased 24 h post ECP (P<0.005). The expression of the co-stimulatory molecules, CD54, CD80 and CD86, remained unaltered on monocytes treated by ECP. Although the mechanism responsible for early induction of lymphocyte apoptosis remains unclear, the later apoptosis involves Fas-L expression. The maintenance of co-stimulatory molecules, on treated monocytes, indicates that they retain the ability to induce an immunomodulatory response.

Treatment of disseminated granuloma annulare with a 5-lipoxygenase inhibitor and vitamin E

Histologically, granuloma annulare (GA) is a common non-infectious necrobiotic granulomatous reaction pattern that correlates with a number of different, but relatively specific clinical presentations. The cause or causes of GA are unknown: when localized, it is usually self-limiting, but it may be persistent when disseminated. We present three women who had had disseminated GA for more than 1 year. One patient had previously been treated with isotretinoin with no response. All three patients were treated with vitamin E 400 IU daily and zileuton 2400 mg daily. All responded within 3 months with complete clinical clearing. The anti-inflammatory and immune regulatory effects of vitamin E and zileuton may be an effective treatment in some patients with prolonged disseminated/generalized GA.

Extracorporeal photochemotherapy in patients with steroid-dependent Crohn's disease: a prospective pilot study

BACKGROUND

Extracorporeal photochemotherapy has been proven effective in selected T-cell mediated diseases.

AIM

To evaluate the safety and efficacy of extracorporeal photochemotherapy in patients with steroid-dependent Crohn's disease by an open, monocentric trial in three phases of 24 weeks each.

METHODS

In phase 1 standardized steroid tapering was initiated in patients with a history of steroid-dependent Crohn's disease. Those with a prospectively evaluated maintenance dose of at least 10 mg/day prednisolone continued steroid-withdrawal under the application of extracorporeal photochemotherapy in phase 2. The duration of remission or response was followed during phase 3. Colonic tissue bioptically obtained before and after extracorporeal photochemotherapy was studied by immunofluorescence microscopy for the presence of photoadduct positive cells.

RESULTS

Out of 24 patients included in phase 1, 10 entered phase 2 for extracorporeal photochemotherapy. Four subjects achieved remission and four others response. Significant reductions in serum C-reactive protein levels and intestinal permeability were measured, as well as increases in quality of life and plasma adrenocorticotropic hormone levels. No major side-effects were observed. Remission remained stable in three out of four patients during phase 3. In three patients, positive nuclear stainings of photoadducts were detected in colonic mononuclear cells after extracorporeal photochemotherapy.

CONCLUSIONS

Extracorporeal photochemotherapy represents a safe steroid-sparing approach in patients with Crohn's disease and is associated with intestinal homing of photopheresed cells.