Extracorporeal photochemotherapy for drug-resistant pemphigus vulgaris

Extracorporeal photochemoimmunotherapy in cutaneous T cell lymphomas

Extracorporeal photochemotherapy (ECP), or photopheresis, is a widely used treatment for cutaneous T cell lymphoma (CTCL) and other T cell-mediated disorders, having been administered in more than 150 centers worldwide more than 200,000 times. Consistent with the theme of this conference--that is, highlighting the potentially most productive investigative avenues for unraveling the mysteries of CTCL in the next decade--ECP has been futuristic since its inception in the early 1980s. In 1988, the treatment was the first FDA-approved selective immunotherapy for any type of cancer. Yet, the mechanism by which it could suppress a clone of CTCL cells or inactivate multiple autoreactive T cell clones in graft-versus-host disease (GVHD) or allograft rejection remained obscure until quite recently. In fact, the scientific principles necessary to begin to comprehend the basis of ECP's efficacy were not available when the treatment was first introduced in 1982. In the intervening years, necessary detailed knowledge of the structure and function of the clonotypic T cell receptors, of class I major histocompatibility complex (MHC) presentation of tumor antigens, of CTCL tumor-specific antigens, of dendritic antigen presenting cell (DC) biology, and of 8-methoxypsoralen immunopharmacology has been attained. Although much remains to be learned, we now appreciate that ECP simultaneously and efficiently induces both apoptosis of disease-causing T cells and conversion of monocytes to functional DCs. By processing and presenting the unique antigenic determinants of pathogenic T cell clones, the DCs can either initiate a clinically relevant anti-CTCL cytotoxic response or suppress the activity of autoreactive T cell clones. This paper will review clinical trials of ECP in CTCL and evolving scientific understanding of ECP's mechanism in the context of exciting future directions.

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.

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.

Emerging treatment for epidermolysis bullosa acquisita

Epidermolysis bullosa acquisita (EBA) is a rare, chronic, subepidermal, mucocutaneous blistering disease characterized by skin fragility and spontaneous as well as trauma-induced blisters that heal with scar formation and milia. Treatment is often frustrating because conventional therapy with corticosteroids and immunosuppressive agents frequently does not result in significant clinical improvement. We review the conventional treatment of EBA and critically analyze the literature on various adjuvants and therapeutic modalities that have recently been used. These include cyclosporine, colchicine, plasmapheresis, extracorporeal photochemotherapy, and intravenous gammaglobulins. Although the data are preliminary, they suggest that intravenous immunoglobulins may be a promising treatment modality for resistant, nonresponsive, or refractory EBA. The use of intravenous immunoglobulins results in significant improvement of skin and mucosal lesions, and it is quite safe, with minimal side effects.

Induction of human tumor-loaded dendritic cells

A preferred anti-cancer vaccine would be tumor-specific, simple to rapidly construct and safe to administer. It would permit immunization against a spectrum of the tumor's distinctive antigens, without requiring their prior identification. Toward these goals, we describe a modification of standard extracorporeal photopheresis (ECP) which initiates, within a single day, both monocyte-to-dendritic cell (DC) differentiation and malignant cell apoptosis. The transition of monocytes to immature DCs was identified by the expression of cytoplasmic CD83 and membrane CD36 in the absence of membrane CD14 staining, as well as induction of membrane CD83 expression. Differentiating DCs were avidly phagocytic and engulfed apoptotic malignant T cells. Differentiating DCs were capable of stimulating significant proliferation of normal alloreactive lymphocyte responders, indicting increased expression of membrane MHC class II molecules. This approach provides a clinically practical means of developing tumor-loaded cells that have initiated the transition to DCs without the requirement of exogenous cytokines, excessive cellular manipulation or isolation. Construction of DC vaccines using this methodology can be generalized to other diseases and may offer a novel approach for improved cancer immunotherapy.

New and emerging therapies for diseases of the oral cavity

It is obvious from the review of the literature that most treatments for oral diseases such as lichen planus, pemphigoid, and pemphigus are based on case reports, anecdotes, and small uncontrolled studies. Efforts must be made to perform more controlled studies to evaluate the efficacy of new treatments. Small numbers of patients at each site and multiple-drug therapy make this task difficult. Dermatologists should familiarize themselves with the newer immunosuppressive agents available. Use of these drugs requires knowledge of their pharmacokinetics and potential side effects, so that they may be used effectively and safely. Relatively low doses of azathioprine, cyclophosphamide, and cyclosporine should then be added to the dermatologist's armamentarium for the treatment of severe or recalcitrant diseases. Old drugs are resurfacing with new (but often off-label) uses as the underlying mechanisms of disease become understood. Thalidomide and mycophenolate mofetil are two examples of promising drugs for the future of dermatology.

New and emerging therapies in the treatment of blistering diseases

The autoimmune vesiculobullous diseases of the skin and mucous membranes are a fascinating group of diseases characterized by blisters of the skin and mucous membranes. These diseases are among the most intriguing, well-characterized, and potentially serious skin diseases known. In recent years, there has been major progress made in the understanding of their pathophysiology, in the development of new diagnostic techniques and of new therapeutic approaches. These advances have placed the autoimmune blistering diseases of the skin and mucous membranes at the forefront of dermatologic advances in the late twentieth century. This article discusses several of the most important autoimmune blistering disease, including bullous pemphigoid, mucous membrane pemphigoid (formerly known as cicatricial pemphigoid), epidermolysis bullosa acquisita, linear IgA bullous dermatosis, pemphigus and paraneoplastic pemphigus, with particular emphasis on the use of new and emerging therapeutic approaches.

Treatment of T lymphocytes with 8-methoxypsoralen plus ultraviolet A induces transient but biologically active Th1-skewing cytokine production

8-Methoxypsoralen plus ultraviolet A light is suggested to shift T lymphocytes from Th2 to Th1 cells. To clarify this issue, we examined the effects of 8-methoxypsoralen/ultraviolet A on the expression/production of cytokines in peripheral blood mononuclear cells from normal subjects and a Sézary syndrome patient. 8-Methoxypsoralen/ultraviolet A augmented the expression of mRNAs for interferon-gamma and interleukin-2 and reduced those for interleukin-4 and interleukin-10. It seems that this enhancement of Th1 cytokines is caused by increment of cytokine production by Th1 cells but not by conversion of Th2 cells to produce Th1 cytokines. The number of interferon-gamma-secreting lymphocytes was markedly increased in 8-methoxypsoralen/ultraviolet A-treated peripheral blood mononuclear cells 20 h after treatment, whereas that of Th2 cytokine-producing cells was decreased. Accordingly, the amount of interferon-gamma was elevated in culture supernatants from 8-methoxypsoralen-phototreated peripheral blood mononuclear cells, whereas interleukin-4 was significantly reduced. This enhanced production of interferon-gamma, however, was found only until 3 d after 8-methoxypsoralen phototreatment and was declined by 5 d after treatment. Finally, 8-methoxypsoralen/ultraviolet A treatment of T cells regulated their ability to induce keratinocyte CD54 expression. Our results show that 8-methoxypsoralen/ultraviolet A has a transient but biologically active Th1-skewing action in human T cells, suggesting that 8-methoxypsoralen/ultraviolet A exerts a beneficial therapeutic effect on Th2-mediated or Th2-malignant diseases.

Long-term application of extracorporeal photochemotherapy in severe atopic dermatitis

BACKGROUND

Extracorporeal photochemotherapy (ECP) using UVA irradiation of enriched leukocytes in the presence of methoxsalen as a photoactivatable substrate has been employed for the treatment of several immunologically mediated disorders.

OBJECTIVE

Our purpose was to determine the efficacy and safety of long-term ECP in the treatment of severe atopic dermatitis.

METHODS

Fourteen patients with severe recalcitrant atopic dermatitis were treated with ECP in an open clinical trial at 2-week intervals. Disease activity was scored before each ECP cycle by means of a standardized protocol.

RESULTS

A complete clinical remission was achieved in 4 patients (29%). Five patients (36%) experienced a substantial response with reduction of skin inflammation by at least 75%, whereas in one patient (7%) disease activity was reduced by more than 50%. Four patients were withdrawn from the study for unresponsiveness. No clinical signs of immunosuppression or other severe adverse events became evident.

CONCLUSION

Long-term ECP may have significant beneficial effects on the course of atopic dermatitis and should therefore be considered as a treatment modality for patients suffering from severe and otherwise refractory atopic skin disease.

Treatment of autoimmune blistering diseases

The treatment of autoimmune blistering diseases remains therapeutically challenging. Significant improvement in the management of autoimmune bullous diseases has occurred as a consequence of improvements in our ability to predict, monitor, and treat the deleterious effects associated with the drugs used to treat these conditions and the introduction of new agents with lower toxicity. Examples include improvements in monitoring and preventing osteoporosis in patients on long-term systemic corticosteroids, the detection of those at risk for azathioprine toxicity bowing to low thiopurine methyltransferase activity, and the addition of agents such as mycophenolate mofetil and IVIG to our therapeutic armamentarium. These advances offer the promise of improved disease control with fewer side-effects and long-term toxicity for our patients.

Modulation of cytokine production by 8-methoxypsoralen and UVA

Modulatory effects on cytokine expression of 8-MOP in conjunction with UVA have been investigated in different systems using different cell types, including keratinocytes, lymphocytes, monocytes and endothelial cells. The vast majority of data have exhibited reduced production of cytokines in 8-MOP/UVA-treated cells and skin, reflecting its simplistic cellular damage. However, 8-MOP/UVA at modest doses stimulate T lymphocytes to produce Thl cytokines such as interferon-gamma, suggesting that some activational events may occur in certain types of cells phototreated with 8-MOP. Both the inhibitory and augmentative effects of 8-MOP/UVA on cytokine production appear to participate in the mechanisms underlying the therapeutic efficacy of PUVA and extracorporeal photochemotherapy (photopheresis). In particular, photopheresis may exert beneficial effects on cutaneous T-cell lymphoma as a cytokine modifier.

The North American experience with photopheresis

Photopheresis or extracorporeal photochemotherapy (ECP) is a novel immunomodulatory therapy based upon pheresis of light-sensitive cells. Whole blood is removed from patients who have previously ingested the photosensitizing agent 8-methoxypsoralen (8-MOP) followed by leukapheresis and exposure of the 8-MOP containing white blood cells (WBCs) extracorporeally to an ultraviolet A (UVA) light source prior to their return to the patient. In 1988, the Food and Drug Administration (FDA) approved photopheresis for the treatment of cutaneous T-cell lymphoma (CTCL). Treatment of CTCL with photopheresis has been reported in over 300 patients worldwide. Photopheresis has also demonstrated encouraging results in the treatment of solid organ transplant rejection, graft versus host disease, scleroderma, and other autoimmune diseases although fewer patients have been studied. This review will focus on the North American experience with photopheresis.

Photopheresis for the prevention of rejection in cardiac transplantation. Photopheresis Transplantation Study Group

BACKGROUND

Photopheresis is an immunoregulatory technique in which lymphocytes are reinfused after exposure to a photoactive compound (methoxsalen) and ultraviolet A light. We performed a preliminary study to assess the safety and efficacy of photopheresis in the prevention of acute rejection of cardiac allografts.

METHODS

A total of 60 consecutive eligible recipients of primary cardiac transplants were randomly assigned to standard triple-drug immunosuppressive therapy (cyclosporine, azathioprine, and prednisone) alone or in conjunction with photopheresis. The photopheresis group received a total of 24 photopheresis treatments, each pair of treatments given on two consecutive days, during the first six months after transplantation. The regimen for maintenance immunosuppression, the definition and treatment of rejection episodes, the use of prophylactic antibiotics, and the schedule for cardiac biopsies were standardized among all 12 study centers. All the cardiac-biopsy samples were graded in a blinded manner at a central pathology laboratory. Plasma from the subgroup of 34 patients (57 percent) who were enrolled at the nine U.S. centers was analyzed by polymerase-chain-reaction amplification for cytomegalovirus DNA.

RESULTS

After six months of follow-up, the mean (+/-SD) number of episodes of acute rejection per patient was 1.44+/-1.0 in the standard-therapy group, as compared with 0.91+/-1.0 in the photopheresis group (P=0.04). Significantly more patients in the photopheresis group had one rejection episode or none (27 of 33) than in the standard-therapy group (14 of 27), and significantly fewer patients in the photopheresis group had two or more rejection episodes (6 of 33) than in the standard-therapy group (13 of 27, P=0.02). There was no significant difference in the time to a first episode of rejection, the incidence of rejection associated with hemodynamic compromise, or survival at 6 and 12 months. Although there were no significant differences in the rates or types of infection, cytomegalovirus DNA was detected significantly less frequently in the photopheresis group than in the standard-therapy group (P=0.04).

CONCLUSIONS

In this pilot study, the addition of photopheresis to triple-drug immunosuppressive therapy significantly decreased the risk of cardiac rejection without increasing the incidence of infection.

Clinical and mechanistic aspects of photopheresis

Photopheresis is an extracorporeal form of photochemotherapy with 8-methoxypsoralen (8-MOP) and ultraviolet A (UVA) radiation. Photopheresis is used for the management of T-cell-mediated diseases, and such treatment leads to the induction of antigen-specific immune suppression directed to the pathogenic clone of T cells. Photopheresis is used to treat a wide variety of diseases--such as cutaneous T-cell lymphoma, systemic sclerosis; rheumatoid arthritis, lupus erythematosus--and is also successfully applied in the suppression of graft rejection. In addition to the clinical achievements, attention will be paid to results from animal studies. An important outcome of these studies is that photopheresis can be used to treat airway hyperreactivity. Furthermore, it was shown that the therapeutic strategy can be changed drastically: the presence of plasma during irradiation should be avoided and the amount of blood that must be treated to obtain the desired antigen-specific immunosuppression can be greatly decreased. Also, results from cellular experiments are discussed. An example of this is the increase in the major histocompatibility complex expression on the surface of cells found after treatment. The mechanism that underlies photopheresis has not yet been elucidated, but progress has been made. The following related points will be reviewed: models for investigation; and mechanistic aspects, with the emphasis on cellular biomacromolecules and on photosensitizers (drugs) other than 8-MOP.

Treatment of cutaneous T-cell lymphoma with extracorporeal photopheresis monotherapy and in combination with recombinant interferon alfa: a 10-year experience at a single institution

BACKGROUND

Extracorporeal photopheresis is a pheresis-based therapy that permits the direct targeting of psoralen-mediated photochemotherapy to circulating pathogenic T cells. Although photopheresis is currently used to treat cutaneous T-cell lymphoma (CTCL), limited data are available regarding overall response rates and durability of responses among patients with advanced disease. Furthermore, little is known about the effectiveness and tolerability of combined regimens employing other biologic response modifiers including interferon alfa.

OBJECTIVE

Our purpose was to determine the efficacy of photopheresis among 41 patients with the clinical and laboratory diagnosis of CTCL; the majority of patients had stage III or IV disease with the presence of circulating malignant T cells.

METHODS

A retrospective chart review during a 10-year period at a single university hospital was performed for all patients receiving either photopheresis monotherapy on two consecutive days every 4 weeks (one cycle) and for an additional 12 patients who also received interferon alfa 1.5 to 5 million U subcutaneously three to five times weekly.

RESULTS

Thirty-one of 41 patients (76%) were treated for six or more cycles. The remaining 10 were treated with less than six cycles because of rapidly progressing disease (n = 6), death unrelated to CTCL (n = 2), or withdrawal from treatment (n = 1); one of the 10 patients had only received five cycles of treatment but is still receiving therapy. Twenty-eight of the 31 patients treated for six or more cycles received photopheresis alone. Among the 28, seven patients (25%) had a complete remission, 13 (46%) had a partial remission defined as more than 50% clearing of skin disease, and eight (29%) did not respond to treatment. The presence of Sézary cells in the peripheral blood was associated with a favorable response. Median time to treatment failure was 18 months, whereas median survival from initiation of therapy was 77 months and from the time of diagnosis exceeded 100 months. Nine of these 28 patients went on to receive combination therapy with interferon alfa and, in some cases, other agents. Among these nine patients, five had an enhanced clinical response to the combination therapy compared with treatment with photopheresis monotherapy. The combined regimen was well tolerated.

CONCLUSION

These results indicate that patients with advanced CTCL can achieve a high response rate for an extended period with photopheresis and that interferon alfa combined with photopheresis is a well-tolerated regimen that appears to produce higher response rates than photopheresis alone.

Cytolytic response to HIV in patients with HIV disease treated with extracorporeal photochemotherapy: preliminary study

Extracorporeal photochemotherapy (photopheresis), an immunomodulatory therapy that targets circulating T helper lymphocytes, has been applied to the management of human immunodeficiency virus (HIV) disease. Any therapy that exerts its actions on CD4+ T cells has the potential of exacerbating HIV infection. Therefore, it was necessary to observe immune function during treatment. Because cytotoxic T lymphocytes (CTL) and natural-killer cells are thought to play an important role in the response against HIV infection, we examined the effect of photopheresis on HIV cytolytic activity. The study group consisted of seven patients with late-stage HIV disease who had not received any previous treatment for HIV infection. Patients were treated exclusively with photopheresis on two consecutive days each month for 14-32 months (average, 25 months). Peripheral lymphocytes, collected at various points during treatment, were used as effectors in a 51Cr release assay. Epstein-Barr virus (EBV)-transformed autologous B cell lines transfected with recombinant vaccinia vectors that expressed the HIV env (gp120, gp41) and gag (p24) proteins were used as target cells. All seven patients demonstrated relatively constant levels of cytolysis (>10% above controls) during treatment in the context of stable CD4+ T cell counts and a stable clinical status. These results suggest that extracorporeal photochemotherapy did not impair the cytolytic response to HIV infection and may have enhanced it in some patients.

Remission of severe epidermolysis bullosa acquisita induced by extracorporeal photochemotherapy

We report a patient with severe epidermolysis bullosa acquisita (EBA) whose disease was refractory to conventional treatments. New bullae continued to develop over greater than 50% of his body surface area despite therapy. His course was complicated by hyperglycaemia, sepsis, hypoxia caused by pulmonary Aspergillus infection and an idiopathic cardiomyopathy. His EBA resolved after treatment with extracorporeal photochemotherapy (ECP). Hence, ECP may be effective in the treatment of severe EBA which has failed to respond to standard treatment regimens.

Extracorporeal photopheresis for the treatment of cutaneous T-cell lymphoma--the Düsseldorf and Munich experience

Extracorporeal photopheresis (ECP) using UVA irradiation of enriched lymphocytes in the presence of 8-methoxypsoralen as a photoactivatable substrate was originally introduced as a therapeutic regimen for cutaneous T-cell lymphoma (CTCL). Whereas ECP has previously been reported to be useful primarily for erythrodermic lymphoma, our purpose was to obtain data on safety and efficacy of ECP in patients suffering from different stages of CTCL. We report on 17 patients, 3 with erythroderma and 14 with plaque or tumor stages. In contrast to other studies our patients were treated predominantly with ECP alone; only a few patients received concomitant therapy. These data have not been published previously, except for preliminary data on four patients. Of the 17 patients, 12 (70%) responded to ECP. In seven patients at least 50% of skin lesions disappeared (defined as partial response) and in five patients at least 25% of skin lesions disappeared (defined as minor response). In two patients the disease remained stable and in three patients the disease progressed under the ECP treatment. No complete remission was observed. Partial responses were achieved not only in patients with early CTCL (stage Ib) but also in those with far progressed tumours (stage IVa). After treatment for 6 months partial responders showed an increase in the number of NK cells in their peripheral blood (P < 0.01). We cannot confirm a relationship between this treatment and CD8 cell counts, as reported by others. Overall, our results indicate that ECP is a safe and effective regimen for the treatment of all stages of CTCL.

Management of the immunobullous disorders. II. Pemphigus

In the second of our reviews on the management of the immunobullous disorders, we review the therapy of pemphigus disorders, including pemphigus vulgaris, pemphigus vegetans, pemphigus foliaceus, pemphigus erythematosus, pemphigus herpetiformis, drug-induced pemphigus, IgA pemphigus and paraneoplastic pemphigus.

T-cell responses in photoimmune therapy

The extracorporeal inactivation of a lymphocyte rich buffy coat suspension with ultraviolet A light and 8 methoxypsoralen can lead to dramatic clinical improvements following reinfusion of the damaged cells. This therapy is reviewed in the context of the disease it is most commonly used for: cutaneous lymphoma. Studies with cutaneous lymphoma patients have shown an active immune response against purified tumor cells. In addition a mouse model for an impact of therapy on a T-cell lymphoma has demonstrated results that parallel those from clinical studies in humans. The impact of photoimmune therapy on in vivo and in vitro T-cell responses to cutaneous lymphoma is discussed.

Review of immunomodulation by photopheresis: treatment of cutaneous T-cell lymphoma, autoimmune disease, and allograft rejection

Photopheresis is an apheresis-based therapy that is currently available at approximately 70 medical centers worldwide. Recent evidence indicates that extracorporeal photopheresis can significantly prolong life as well as induce a 60-75% response rate among individuals with advanced cutaneous T-cell lymphoma (CTCL). Moreover, a 10-15% cure rate, in response to photopheresis alone, or in combination with interferon-alpha, has been obtained at our institution. These complete responses have been characterized by the complete disappearance of morphologically atypical cells from the skin and blood. Southern blot analysis of peripheral blood specimens has also confirmed the indefinite disappearance of the malignant T-cell clone from the blood of patients with complete responses. Current immunological data obtained from in vitro human studies and from animal models suggest that the basis for the responses of CTCL patients are related to activation of treated macrophages resulting in release of cytokines, including substantial levels of tumor necrosis factor alpha (TNF-alpha), and perhaps, to the induction of anticlonotypic immunity directed against pathogenic clones of T lymphocytes. In addition to the treatment of CTCL, a potential role for photopheresis in the therapy of autoimmune disease has been suggested by recent pilot studies of pemphigus vulgaris, rheumatoid arthritis, and systemic lupus erythematosus. Furthermore, a randomized, single-blinded trial involving 79 patients with early onset, aggressive systemic sclerosis suggested that photopheresis could benefically affect the course of the cutaneous thickening in this form of the disease. Lastly, two independent pilot studies of cardiac transplantation have indicated that photopheresis can reverse acute cardiac allograft rejection and potentially suppress ongoing chronic rejection. Randomized, controlled trials for these new indications for photopheresis therapy are currently in the early stages of implementation.

Extracorporeal photochemotherapy: evaluation of two techniques and use in connective tissue disorders

Extracorporeal photochemotherapy (ECP) consists of collection of mononuclear cells, their irradiation with UV-A light in the presence of a photoactivable molecule--8-methoxy-psoralen (8-MOP) being the most widely used--and their reinjection into a patient. Two technical approaches have been developed. The photopheresis procedure involves four steps: (i) 8-MOP is given to the patient orally, 2 h before collection of white blood cells; (ii) a discontinuous flow cell separator (UVAR, Therakos, West Chester, PA, U.S.A.) is used for cell collection. The final product (740 mL) has a hematocrit of 4.5 +/- 1.7%); (iii) irradiation, performed with the same UVAR apparatus, begins before all the cells are collected, and lasts for 180 min after collection; and (iv) after irradiation, the buffy-coat is reinjected into the patient. We developed a technique summarized as follows: (i) mononuclear cell collection is performed using the Spectra (Cobe, Denver, CO, U.S.A.) cell separator, which provides a highly enriched mononuclear cell concentrate (always > 90% purity), in a small volume < 150 mL, subsequently adjusted to 300 mL for irradiation. Hematocrit of the final product is always < 2%. (ii) Soluble 8-MOP is added to the mononuclear cell concentrate at a final concentration of 200 ng/mL. (iii) Mononuclear cell concentrate is transferred in an EVA plastic bag (Macopharma, Tourcoing, France) to ensure an efficient irradiation with a UV irradiator (Vilber Lourmat, Marne-la-Vallée, France). (iv) After irradiation at 2 J/cm2 (time < 20 min), the cells are reinfused into the patient. Experimental and clinical data suggest that ECP has potential applications in the treatment of connective tissue disorders, such as systemic sclerosis and rheumatoid arthritis. Although encouraging data have been obtained, further clinical trials are warranted to establish the role of this therapy in these indications.

Treatment of severe atopic dermatitis with extracorporeal photopheresis

Extracorporeal photopheresis using UVA irradiation of enriched lymphocytes in the presence of 8-methoxypsoralen (8-MOP) as a photoactivatable substrate has been employed for the treatment of several immunologically mediated disorders. We report on the first three patients subjected to extracorporeal photopheresis for severe atopic dermatitis. All patients had a lifelong history of atopic skin inflammation, and their disease had finally become resistant to well-established therapeutic regimes. Extracorporeal photopheresis resulted in a marked clinical improvement in the skin lesions of all patients. The decrease in cutaneous inflammatory activity became evident by the end of the second photopheresis cycle. In two patients skin lesions had virtually disappeared after the fifth treatment cycle, while in the third patient a lasting and substantial improvement in pruritus and erythema was achieved. Clinical remission was stable under maintenance therapy with prolonged intervals between photopheresis sessions. Therapeutic efficacy was reflected by a marked reduction in IgE serum levels in all three patients, while serum concentration of IgG, IgM and IgA as well as the profile of circulating lymphocytes remained essentially unchanged. No clinical signs of immunosuppression or other severe adverse events became evident. Collectively, our preliminary results indicate that extracorporeal photopheresis may interfere with the pathomechanisms leading to atopic dermatitis and therefore should be considered as a treatment modality for severe forms of this recalcitrant disorder.

Intervention at diagnosis of type I diabetes using either antioxidants or photopheresis

Two main hypotheses support the contention that type I diabetes is an autoimmune disease, namely "the cytokine hypothesis" and "the T-lymphocyte hypothesis". Various strategies can be used at diagnosis with a view to stopping beta-cell destruction or at least attenuating the process. This review discusses the use of antioxidants based on the idea that free oxygen radicals are important mediators. Experimental animal models have indicated that several antioxidants may prevent diabetes, although in humans only nicotinamide has been shown to have some effect on preventing the disease in high-risk individuals and to produce a slight effect on residual insulin secretion in newly diagnosed patients. Bearing in mind these considerations, we tried a cocktail of several antioxidants at high dosage. As the code of this randomized double-blind study is not broken, results cannot be given, but preliminary observation indicates that there has been no dramatic increase of complete remission. Based on the hypothesis that type I diabetes is a T-lymphocyte-mediated disease, lymphocyte photopheresis may be useful. Photopheresis, comprising the treatment of lymphocytes by a combination of the light-activated drug methoxypsoralen and UVA irradiation, has been shown to be effective in the treatment of some other autoimmune disease. One hypothesis regarding its efficacy holds that the method causes changes in the antigenicity of the treated lymphocyte clones which cause a vaccination-like effect when these cell lines are retransfused at repeated intervals into the patient. Nothing to date is known about its effect in diabetes, although a double-blind randomized placebo-controlled study has been commenced.

Parenteral administration of 8-methoxypsoralen in photopheresis

BACKGROUND

Extracorporeal photochemotherapy (EP) is used for the treatment of cutaneous T-cell lymphoma (CTCL), progressive systemic sclerosis (PSS), pemphigus vulgaris, and rheumatoid arthritis. During this procedure, the oral administration of the photoactive drug 8-methoxypsoralen (8-MOP) results in an unpredictable range of serum levels and in side effects limiting its efficacy.

OBJECTIVE

To circumvent this limitation, extracorporeally administrable 8-MOP (EX-8-MOP) was developed. It is administered directly to the leukocyte/plasma concentrate in the treatment bag of the EP apparatus before irradiation with UVA light.

METHODS

Efficacy, tolerance, and side effects of EX-8-MOP were evaluated in 108 consecutive treatments of 16 patients who had previously been treated with oral 8-MOP (91 treatments).

RESULTS

With EX-8-MOP constant drug levels for UV light exposure were obtained; for equivalent levels only a small fraction of the oral dose (1/250 to 1/500) was required with none of the side effects associated with oral 8-MOP. Effective and reproducible inhibition of lymphocyte proliferation and cell viability was attained. No difference in clinical efficacy could be observed.

CONCLUSION

EX-8-MOP eliminates the need for premedication and drug level monitoring of 8-MOP and should improve the effectiveness of EP.

Treatment of erythrodermic cutaneous T-cell lymphoma with extracorporeal photochemotherapy

BACKGROUND

This original cohort of patients with erythrodermic cutaneous T-cell lymphoma (CTCL) was reported to have clinical improvement with photopheresis during the 12 months of the original study. No long-term follow-up data have been available to examine the impact of this therapy on the disease.

OBJECTIVE

Our purpose was to provide long-term follow-up on the original 29 erythrodermic CTCL patients treated with photopheresis and to compare these results with historical controls.

METHODS

Files of patients from the original photopheresis study centers were reviewed and their current status was documented.

RESULTS

The median survival of the treated patients was 60.33 months from the date of diagnosis and 47.9 months from the date of the start of photopheresis therapy. A complete remission has been maintained in four of the six patients who achieved complete responses in the original study. The best responses were seen in patients with a lower CD4/CD8 ratio in the peripheral blood at the start of therapy.

CONCLUSION

Photopheresis can influence the natural history of erythrodermic CTCL by inducing remissions and prolonging survival with minimal toxicity.

Determination of 8-methoxypsoralen in plasma by gas chromatography-mass spectrometry using selected-ion monitoring

A sensitive and accurate assay was developed for the measurement of 8-methoxypsoralen in plasma using electron-impact positive-ion mass fragmentography. 4,5,8-Trimethylpsoralen was used as an internal standard. Sample preparation consisted of a two-step liquid phase extraction using acetonitrile and methylene chloride. The calibration curve showed a linear relationship between the peak areas of 8-methoxypsoralen and 4,5,8-trimethylpsoralen over a wide range of 8-methoxypsoralen concentrations (1-500 ng/ml). With-in- and between-run precisions, measured at five different drug concentrations, varied from 0.82 to 1.41% and from 0.82 to 1.86%, respectively.

Photopheresis for rheumatoid arthritis

For rheumatoid arthritis, an effective therapy with minimal toxicity would be welcome. In a six-month pilot study of seven patients with a variety of presentations and previous treatments, we tested a therapy involving the extracorporeal photoactivation of biologically inert methoxsalen (8-methoxypsoralen) by ultraviolet A energy to a form that covalently cross-links lymphocyte DNA; the injured cells are returned to the patient. Prior experimental studies had indicated that this regimen produces an immune reaction against antigens on treated T Cells, and a clinical trial in cutaneous T cell lymphoma had been successful. The current patients were treated on two successive days monthly (or, later on, biweekly). Between 12 and 16 weeks of therapy there appeared to be a breakpoint after which joint counts and joint scores of four patients began to improve. In three of them, these measures eventually diminished by mean values of 71% and 80%, respectively, of their baseline values, along with variable improvement in less direct indicators of clinical response. The joints of the fourth patient improved modestly (by 33% and 59%, respectively, of baselines) but he required alternative therapy, and those of the remaining three patients did not improve. Mean slopes for the joint counts were significantly different from zero after the apparent breakpoint (but not before), whether one examined the four apparent responders (p = 0.01) or the entire group of seven (p = 0.01). After completion of therapy, there was also a delay, of two to three months, in the clinical deterioration of those who had improved. There was only one mechanical adverse effect--a single episode of transient hypotension in 102 treatment sessions--and no toxic ones. This preliminary study suggests that extracorporeal photochemotherapy may be effective at least in the short term in certain patients with rheumatoid arthritis, with less apparent toxicity than that of any of the drugs currently used for this disorder. It deserves further evaluation.

Inhibition of antiskin allograft immunity induced by infusions with photoinactivated effector T lymphocytes (PET cells). Is in vivo cell transferrable?

We previously reported producing donor-specific tolerance to alloantigens by intravenous exposure to pretreated antidonor T cells. The current study extends that work by adoptively transferring the donor-specific tolerance into naive syngeneic recipients. Eight days after BALB/c mice received histoincompatible CBA/j skin grafts, their splenocytes which included an expanded population of cells mediating rejection were treated with 100 ng/ml 8-methoxypsoralen (8-MOP) photoactivated by 1 Joule/cm2 of ultraviolet A (UVA) light prior to infusion into naive BALB/c recipients. Whereas 8-MOP itself is biologically inert, photoactivated 8-MOP crosslinks DNA by covalently binding to pyrimidine bases. Recipient BALB/c mice which had been previously demonstrated to be hyporesponsive to CBA/j alloantigens in mixed leukocyte culture (MLC), cytotoxicity (CTL) and in vivo delayed type hypersensitivity (DTH) assays were the donors of spleen cells for the adoptive transfer experiments. Fifty to one hundred million viable spleen cells from these pretreated BALB/c mice were transferred into naive syngeneic recipients which then were tested for DTH response and allograft survival to the relevant and irrelevant antigens. The radiosensitivity of this transferrable suppression was evaluated by exposing the adoptively transferred cell population to 3200 rads of C-irradiation prior to cell transfer. The phenotype of the cells transferring this suppressive response was performed by depleting specific populations of cells with monoclonal antibodies prior to cell transfer. In vivo the DTH response of the pretreated BALB/c mice was specifically suppressed to the relevant alloantigen, correlating with retention of CBA/j skin grafts for up to 42 days post engraftment without visual evidence of rejection, in comparison to control mice complete rejection of the skin graft in less than 8 days. In vitro, splenocytes from BALB/c recipients of pretreated syngeneic splenocytes containing large numbers of BALB/c anti-CBA/j T cells proliferated less in MLC and generated lower cytotoxic T cell responses to CBA/j alloantigens than did controls and suppressed the naive and sensitized BALB/c MLC and CTL responses to CBA/j alloantigen. This specific suppressive response to alloantigen was optimally transferred into syngeneic naive recipients when the adoptive transfer was performed on the sixth day after the last infusion received by the spleen cell donor mice. The adoptive transfer of this suppressive response was abrogated by the prior X-irradiation of the donor spleen cells and significantly abolished by the depletion of Thy-1+, Lyt-2+, L3T4- T lymphocytes.(ABSTRACT TRUNCATED AT 400 WORDS)