Inhibition of autoimmune disease in a murine model of systemic lupus erythematosus induced by exposure to syngeneic photoinactivated lymphocytes

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.

The treatment of autoimmune disease in (NZB/NZW)F1 mice with syngeneic photomodulated splenocytes

(NZB x NZW)F1 (B/W) mice spontaneously develop a disease which is remarkably similar to systemic lupus erythematosus (SLE) in humans. This disease is characterized by the appearance of autoantibodies to double-stranded (ds)DNA and the subsequent development of fatal glomerulonephritis. The prophylactic treatment of B/W mice with syngeneic photomodulated autoimmune spleen cells was found to significantly improve survival, and to inhibit the outgrowth of autoreactive B cells and the production of high-titre IgG anti-dsDNA antibodies. The function of the autoreactive T cells in vivo, however, did not change significantly. Our findings suggested a novel treatment for spontaneously occurring autoantibody-related autoimmune diseases.

Photodynamic therapy; a comparison with other immunomodulatory treatments of adjuvant-enhanced arthritis in MRL-lpr mice

Although numerous experimental immunomodulatory regimens have been reported to be effective in the treatment of rheumatoid arthritis, they also produce undesirable side effects. An alternative specific modality of localized treatment is photodynamic therapy (PDT). In this study we treated 13-week-old MRL-lpr mice whose spontaneous arthritis was enhanced by intradermal injection of Freund's complete adjuvant (FCA). One group received transcutaneous photodynamic therapy at days 0, 10, and 20, following the FCA injection. The other groups were injected with 1 mg/kg per day indomethacin, 40 mg/kg per day cyclosporin A (CsA), or treated with 3 Gy sublethal whole body irradiation (WBI). The development of swelling was monitored for 1 month, at which time proteinuria, lymphadenopathy and the histopathology of the joints and kidneys were assessed. The results demonstrated that PDT and the conventional treatments significantly ameliorated swelling of the hindlimbs from 70% in the untreated FCA-injected animals to below the 19% level characteristic of the unmanipulated control. Histological examination showed a reduction in pannus formation, and cartilage and bone destruction, the characteristics of adjuvant-enhanced arthritis. PDT did not affect the survival rate, lymphoproliferation, or proteinuria of the treated animals. However, indomethacin increased proteinuria, and was less effective in preventing cartilage and bone destruction. Furthermore, lower doses of CsA and WBI exacerbated arthritis activity. These results indicate that photodynamic therapy can inhibit the development of adjuvant-enhanced arthritis in MRL-lpr mice with similar effectiveness to the conventional treatments, but without their negative side effects.

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.

The treatment of mastocytoma cells with 8-methoxypsoralen and long-wavelength ultraviolet radiation enhances cellular immunogenicity: preliminary results

Evidence for the increased immunogenicity of mastocytoma cells (P815) treated with 8-methoxypsoralen (8-MOP) and long-wavelength ultraviolet radiation (UVA) is presented. A highly tumorigenic clone (P1) became much less tumorigenic (tum-) after repetitive phototreatments with 8-MOP (16 ng/mL) and UVA (1 J/cm2). The yield of tum- clones was proportional to the number of phototreatments. In a pilot study in which P1 cells were treated with three successive rounds of 8-MOP/UVA, one clone out of 73 was tum-. In a second series of experiments, the P1 cells were treated 10 times and 4 out of 100 clones were much less tumorigenic. When some of the tum- clones were administered intraperitoneally to DBA/2 mice, significant protection against challenge with the original P1 clone was observed. In addition, the transfer of immune cells from tum(-)-treated mice allowed the transfer of resistance to other tum- clones to immunosuppressed mice (650 rad). These results are consistent with earlier literature showing the potent mutagen, N-methyl-N'-nitrosoguanidine, led to mutations in P1 that altered the expression of new surface antigens, which stimulated the murine immune system such that there was also cross recognition of shared antigens on untreated P1 cells used to challenge the immunized mice. The increased immunogenicity that resulted from the less mutagenic 8-MOP/UVA treatment may arise by a similar mechanism and may be responsible in part for the efficacy of 8-MOP/UVA photochemotherapy for the treatment of cutaneous T cell lymphoma.

An animal model and new photosensitizers for photopheresis

Recently, photopheresis was introduced as a therapy for several T cell-mediated disorders. The treatment results in a specific immune response against the pathogenic clone of T cells involved. However, although promising there is controversy concerning the use of photopheresis in some diseases, e.g. systemic sclerosis. One of the problems is that there is not yet sufficient insight into the mechanism underlying the therapy. This lack of knowledge is partly caused by the fact that there are no easy-to-handle animal models available for photopheresis. This report describes such a model--a Wistar-derived rat with contact hypersensitivity (CHS); a T cell-mediated immune response. White blood cells from CHS rats were simultaneously exposed to 8-methoxypsoralen (8-MOP) and ultraviolet A radiation (UVA) and subsequently intravenously injected into other syngeneic rats suffering from the same disorder. This treatment appears to be very efficacious in suppressing the immunological response against the applied contact allergen, 2,4-dinitrofluorobenzene (DNFB). In addition, the generated suppression of CHS is highly specific and transferable. Furthermore, drugs other than 8-MOP (chlordiazepoxide, nitrofurantoin and chlorpromazine) also appear to be active in our model.

Inefficacy of extracorporeal photochemotherapy in the treatment of B-cell chronic lymphocytic leukemia: preliminary results

Because extracorporeal photopheresis has been shown to be clinically effective in Sezary syndrome, a disease characterized by a circulating malignant clone, we initiated a pilot study of its use in B-cell chronic lymphocytic leukemia (B-CLL) to see if it could be similarly effective. We treated three patients with Rai stage III and IV B-CLL with photopheresis (3 consecutive days a week every 3 weeks) and followed serial clinical and immunologic parameters. While we noted no major toxicity, there was neither clinical response to treatment nor marked improvement in white counts or mitogen assays. We conclude that photopheresis was not effective in inducing remission in this pilot study of advanced stage B-CLL patients.

An animal model for extracorporeal photochemotherapy based on contact hypersensitivity

Recently, photopheresis was introduced as a specific immune suppressor in several T cell mediated disorders. In order to study photopheresis, animal models are indispensable. This report describes an easy to handle model for this purpose. It concerns the Wistar-derived rat with contact hypersensitivity (CHS), also a T cell mediated disorder that has already been studied extensively in several other fields of research. After subsequent exposure to 8-methoxypsoralen (8-MOP) and ultraviolet A radiation (UVA), white blood cells from CHS rats were intravenously injected into other syngeneic rats suffering from the same disorder. This treatment appears to be very efficacious in suppressing the immunological response against the applied contact allergen, 2,4-dinitrofluorobenzene (DNFB). Cells subsequently exposed to UVA and 8-MOP did not have any effect.

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.

Extracorporeal photochemotherapy for the treatment of systemic lupus erythematosus. A pilot study

OBJECTIVE

To investigate the effectiveness and feasibility of extracorporeal photochemotherapy (ECP) in the treatment of an autoimmune disease with known cutaneous photosensitivity.

METHODS

Ten patients with systemic lupus erythematosus (SLE) were treated with ECP in an open clinical trial. The efficacy of treatment was analyzed by means of established disease activity scores.

RESULTS

Eight patients completed the trial. In 7 of the 8, there was a significant response to the treatment, with no or minor side effects. The clinical activity score in the group of 8 patients decreased from a median of 7 (range 4-9) to a median of 1 (range 0-5) (P less than 0.05). Laboratory abnormalities did not change significantly, but were mild at the outset.

CONCLUSION

ECP led to clinical improvement of SLE without side effects. The effectiveness of this method should be investigated further in controlled clinical trials.

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.

Photopheresis: a clinically relevant immunobiologic response modifier

Photopheresis, the process by which peripheral blood is exposed in an extracorporeal flow system to photoactivated 8-methoxypsoralen (8-MOP), is an effective new treatment for certain disorders caused by aberrant T lymphocytes. It has become a standard therapy for advanced cutaneous T cell lymphoma and shows promise in the treatment of four autoimmune disorders (pemphigus vulgaris, the progressive systemic sclerosis form of scleroderma, rheumatoid arthritis, systemic lupus erythematosus) and in reversal of immunologic rejection of transplanted organs. Positive immunologic alterations observed in patients with AIDS-related complex merit further investigation, and preliminary trials in the management of patients with multiple sclerosis, myasthenia gravis and autoimmune insulin-dependent diabetes mellitus have recently been initiated. The inability of the treatment to meaningfully alter the course of the B cell malignancy, chronic lymphocytic leukemia, suggests that B cell proliferations, at least those involving malignant cells, may be more resistant to this treatment. The mechanism of action of photopheresis is likely to be multifaceted, but at least in experimental systems appears to involve an immunization against the pathogenic T cells, in a highly specific manner. Photoactivated 8-MOP initiates a cascade of cellular events by forming covalent photoadducts with nuclear DNA, with cell surface molecules and possibly with other cytoplasmic components of the ultraviolet exposed leukocytes. For reasons not yet clear, exposure of populations of T cells containing expanding a clone(s) of pathogenic T cells to photoactivated 8-MOP alters these cells so that their reinfusion induces a therapeutically significant immunologic reaction that targets unirradiated T cells of the same pathogenic clone(s). It is suggested that the specificity of the induced immunologic reaction may result, in sequence, from the exquisitely titratable damage that 8-MOP inflicts upon cells of the pathogenic clone(s), the return of these cells to an immunocompetent individual, the removal of the photo-damaged cells from the blood by the reticuloendothelial system and the preferential induction of an immune response against cells of the pathologically expanded clone(s).

Autoregulation of the immune response in autoimmune disease and cardiac transplantation by photoinactivated autologous lymphocytes

These studies demonstrate that photochemotherapy can be successfully evaluated in animal models. The therapy mediates specific suppression of immune responses and appears to operate at the level of the effector T cells. Future studies will focus on isolation and characterization of the host response to photochemotherapy. The extention of this form of therapy to conditions mediated by dysfunctional regulation of effector T cells is already in progress in clinical trials of cardiac allograft transplantation and autoimmune disease. The results of these trials will provide more evidence on the role of this form of therapy in autoregulation of the immune response.

Treatment of rheumatoid arthritis by extracorporeal photochemotherapy. A pilot study

In a 6-month pilot study of 7 patients with rheumatoid arthritis, we tested a treatment 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 reinfused into 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 patients with cutaneous T cell lymphoma had been successful. The current study patients were treated monthly, on 2 successive days (or biweekly, later on). Between 12 and 16 weeks of therapy, there appeared to be a breakpoint, after which the joint counts and joint scores of 4 of the patients began to improve. In 3 of the 4 patients, these measures eventually diminished by a mean of 71% and 80% of baseline values, respectively, and there was variable improvement in less direct indicators of clinical response. The joint counts and scores of the fourth patient improved modestly (by 33% and 59% of baselines, respectively) but he required alternative therapy, and those of the remaining 3 study 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 4 apparent responders (P = 0.01) or the entire group of 7 patients (P = 0.01). After completion of therapy, there was also a delay, of 2-3 months, in the clinical deterioration of those patients who had improved. There was only 1 mechanical adverse effect--a single episode of transient hypotension in 102 treatment sessions--and no toxic effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Photoinactivation of T-cell function with psoralen and UVA radiation suppresses the induction of experimental murine graft-versus-host disease across major histocompatibility barriers

Bone marrow transplantation is employed in the treatment of a number of hematologic and malignant diseases. A major complication is the induction of graft-versus-host disease. Whereas removal of T lymphocytes from the donor marrow effectively reduces the incidence of graft-versus-host disease, the incidence of graft failure often increases when T cells are depleted from the transplanted marrow. In the current study, photoinactivation of the donor cells with 8-methoxypsoralen coupled with exposure to long-wavelength ultraviolet radiation (PUVA therapy) was used to inactivate the response of the donor T cells against the host. PUVA therapy suppressed the ability of spleen cells to respond to alloantigen in the in vitro mixed lymphocyte reaction. The induction of acute graft-versus-host disease across complete major histocompatibility barriers in lethally X-irradiated mice was significantly suppressed after bone marrow transplantation with photoinactivated bone marrow cells. Long-term survivors demonstrated allogeneic reconstitution and partial restoration of T-cell function. Because PUVA therapy had no inhibitory effect on hematopoiesis, these data suggest that using phototherapy to inactivate the alloreactivity of T cells may provide an alternative to purging T cells from the donor marrow, thus suppressing both the incidence of graft-versus-host disease and the incidence of graft failure.

Extracorporeal photopheresis in psoriasis vulgaris: clinical and immunologic observations

Four patients with chronic refractory plaque-type psoriasis without arthropathy were treated with extracorporeal photopheresis every other week for 6 to 13 months. In patients 1 and 2, methotrexate was administered concomitantly during the initial part of the trial; the dose was gradually tapered and the drug was discontinued by 6 months. Both patients improved to 23% and 62% of baseline values for percentage of body surface involvement, but their disease then flared when maintenance extracorporeal photopheresis was used alone. Substantial improvement again occurred when lower doses of methotrexate were administered with extracorporeal photopheresis. Patients 3 and 4 were treated initially with extracorporeal photopheresis alone and both improved to 50% and 52% of baseline body surface involvement, respectively, after 4 months of treatment. However, their disease flared because of factors unrelated to treatment. Extracorporeal photopheresis was well tolerated by all patients without evidence of overt toxicity. However, prolonged treatment with extracorporeal photopheresis/methotrexate was accompanied by a decrease in skin reactivity to recall antigens and by decreased capacity of lymphocytes to produce interleukin 2 in response to polyclonal stimuli in vitro. These findings indicate that alternate-week extracorporeal photopheresis has a definite but incomplete suppressive effect on psoriasis vulgaris that may be mediated through an effect on lymphokine production by photomodified cells and that the therapeutic effect of extracorporeal photopheresis may be enhanced by concomitant administration of low doses of methotrexate.