Serial immune evaluation of cyclosporine- and placebo-treated multiple sclerosis patients

Basic immunosuppressive drugs outside solid organ transplantation

Immunosuppressive drugs are the backbone of solid organ transplantation. The introduction of new immunosuppressive drugs led to improved patient and organ survival rates. Nowadays, acute rejection can be reduced to a minimum. Individualization and avoidance of drug-related adverse effects became a new goal to achieve. The potency of immunosuppressive drugs makes them attractive for use in various autoimmune diseases; therefore, the experience on immunosuppressive drugs outside the field of organ transplantation is analysed in this review.

Current immunotherapy in multiple sclerosis

The underlying pathophysiology of multiple sclerosis is presumed to be autoimmune in nature. Attempts to find an effective treatment for this common disease of the central nervous system have primarily focused on immune-mediated therapies, both immunosuppressive and immunomodulatory. The wide variety of immunological abnormalities detected in multiple sclerosis and its animal model, experimental allergic encephalomyelitis, has prompted the testing of a diverse array of drugs to be used for treatment. Recent successes in the treatment of relapsing-remitting multiple sclerosis with interferon beta and glatiramer acetate have renewed interest in and raised expectations for the effective control of this neurological disorder. Improved methodology in clinical trials, the development of surrogate markers and the availability of novel therapies bode well for more rapid advances.

Recent advances in the pharmacological control of experimental allergic encephalomyelitis (EAE) and the implications for multiple sclerosis treatment

The autoimmune, cell-mediated condition experimental allergic encephalomyelitis (EAE) is the representative model for the inflammatory central nervous system disease MS. EAE has been extensively employed to determine the efficacy of pharmacological agents that may be of ultimate use in the treatment of MS. A wide variety of drugs has been examined for activity in EAE but, over the last decade, three groups of compounds have emerged with clear and reproducible ability to modify significantly the onset and progression of the disease. The immunosuppressants, the modulators of catecholamine activity and the antineoplastic agents have convincingly altered the course of EAE and, as a consequence, provided understanding of the mechanisms of disease expression and offered further insight into the pathogenesis of MS. The article stresses the usefulness of EAE as a model to identify prospective pharmacological treatments for MS and, in particular, considers those compounds subsequently assessed for their ability to interfere with the progression of the human disease.

Peripheral blood leukocytes from multiple sclerosis patients are coated with factors inhibiting their chemotaxis in the presence of myelin basic protein

In this study myelin basic protein (MBP) was tested for its effect on chemotaxis of human peripheral blood leukocytes (PBL) and neutrophils from multiple sclerosis (MS) patients. MBP appeared to inhibit specifically the formyl-methionyl-leucyl-phenylalanine (FMLP)-induced chemotaxis of both the total leukocyte population and neutrophils. In comparison, no inhibition of chemotaxis was observed in healthy donors and patients with other neurological diseases. From MS patients we collected neutrophil supernatants obtained by incubation of the cells in a serum-free medium at 37 degrees C for 60 min and evaluated their effect on chemotaxis of neutrophils from healthy donors. Chemotaxis of healthy donor neutrophils was inhibited specifically in the presence of MBP after treatment with these supernatants, presumably relating to the presence of immune complexes on the surface of neutrophils from MS patients. Those complexes can be eluted into the incubation medium and coat healthy donor neutrophils, thus arming them specifically.

Serial studies of serum interleukin-2 in chronic progressive multiple sclerosis patients: occurrence of 'bursts' and effect of cyclosporine

Serum levels of immunoreactive interleukin-2 (IL-2) were determined at monthly intervals from a group of placebo- and drug-treated chronic progressive multiple sclerosis patients before and during a cyclosporine A therapeutic trial. Significantly elevated levels of the lymphokine in active patients confirmed earlier studies. The magnitude of the initial levels varied inversely with the duration of disease and predicted subsequent worsening in chronic progressive patients. In addition, the occurrence of periodic bursts of serum IL-2 was noted. Although in some patients there appeared to be a sudden drop in serum IL-2 levels with the onset of cyclosporine A medication, no effect of this drug was noted on group analysis.

Efficacy and toxicity of cyclosporine in chronic progressive multiple sclerosis: a randomized, double-blinded, placebo-controlled clinical trial. The Multiple Sclerosis Study Group

Patients with clinically definite multiple sclerosis, mild to moderately severe neurological disability (entry score on the Expanded Disability Status Scale (EDSS) between 3.0 and 7.0), and a progressive course defined by an increase in the EDSS of between 1 and 3 grades in the year prior to entry were randomized to receive either cyclosporine (n = 273) or placebo (n = 274) in a 2-year, double-blinded, multicenter trial. Treatment groups at entry proved balanced for age, gender, duration of illness, and neurological disability. Cyclosporine dosage was adjusted for toxicity and a median trough whole-blood level was maintained between 310 and 430 ng/ml. The mean increase in EDSS score was 0.39 +/- 1.07 grades for cyclosporine-treated patients and 0.65 +/- 1.08 grades for placebo-treated patients from entry until the time of early withdrawal or completion of the study (p = 0.002). Of three primary efficacy criteria, cyclosporine delayed the time to becoming wheelchair bound (p = 0.038; relative risk, 0.765), but statistically significant effects were not observed for "time to sustained progression" or on a composite score of "activities of daily living." Active treatment did have a favorable effect on several secondary measures of disease outcome. A large and differential withdrawal rate (44% for cyclosporine-treated patients, 32% for placebo-treated patients) complicated the analysis but did not appear to explain the observed effect of cyclosporine in delaying disease progression. Multivariate analysis did not show institutional effects but did demonstrate substantial effects of baseline neurological disability on outcome. Nephrotoxicity and hypertension were common troublesome toxicities and accounted for most of the excess loss of patients in the cyclosporine arm of the study. Thus, chronic cyclosporine therapy was associated with a statistically significant but clinically modest delay of progression of disability in a group of patients with multiple sclerosis selected for moderately severe and progressive disease. Close supervision by physicians familiar with cyclosporine is mandatory to minimize known adverse effects, particularly nephrotoxicity, when considering the use of this immunosuppressant.

T cells responsive to myelin basic protein in patients with multiple sclerosis

Gene mutation in vivo in human T lymphocytes appears to occur preferentially in dividing cells. Individuals with multiple sclerosis (MS) are assumed to have one or more populations of diving T cells that are being stimulated by autoantigens. Mutant T cell clones from MS patients were isolated and tested for reactivity to myelin basic protein, an antigen that is thought to participate in the induction of the disease. The hypoxanthine guanine phosphoribosyltransferase (hprt) clonal assay was used to determine mutant frequency values in MS patients with chronic progressive disease. Eleven of 258 thioguanine-resistant (hprt-) T cell clones from five of the six MS patients who were tested proliferated in response to human myelin basic protein without prior in vitro exposure to this antigen. No wild-type clones from these patients, nor any hprt- or wild-type clones from three healthy individuals responded to myelin basic protein. Thus, T cell clones that react with myelin basic protein can be isolated from the peripheral blood of MS patients.

Cyclosporin A curtails the progression of free light chain synthesis in the CSF of patients with multiple sclerosis

Free light chains in the cerebrospinal fluid of patients with multiple sclerosis correlate closely with disease activity. As part of a double-blind placebo controlled trial of immunosuppression using cyclosporin A in patients with multiple sclerosis, light chain analysis was performed on pre- and post-treatment CSF samples in 19 patients, nine having received cyclosporin A and 10 placebo. The placebo treated patients showed continued immunological activity, as evidenced by an increase in both free kappa and lambda chains, but cyclosporin A treatment resulted in no change or an improvement in light chain response, indicative of suppression of continued activity. As cyclosporin A does not enter the CSF, this implies that systemic stimulation is at least partly responsible for continued disease activity in multiple sclerosis. Cyclosporin A may thus be effective in preventing the deterioration of patients with multiple sclerosis.

Effect of cyclosporine on rubella virus-specific immune responses in chronic progressive multiple sclerosis

Cyclosporine A (CsA) has been used in putative autoimmune diseases after sensitization to unknown antigens. We have previously shown that CsA prevented continued activation of T-cells in chronic progressive multiple sclerosis (CPMS) patients. The current study was undertaken to determine whether CsA, or CsA and prednisone (CsA + P) could suppress immune responses to a common recall antigen. Serum antibody levels were higher in all CPMS patients than age-matched normal controls. However, rubella antibody titers in the CsA or CsA + P groups were no different from a placebo-treated CPMS patient group. The lymphocyte responses to inactivated rubella virus of CsA and CsA + P-treated CPMS patients were lower than placebo and control but not statistically different. Therapy with both CSA and CSA + P was associated with significantly lower panel mixed leukocyte responses and Ta1 expression than in the placebo-treated group; CD3, CD4, CD8 antigen expression and active rosette formation by T-cells were similar for the three CPMS groups. These results suggest that while CsA exerts measurable effects on non-specific indicators of cellular immunity in CPMS patients, it may not be as effective in suppressing pre-existent specific immune responses.

MS: a CNS and systemic autoimmune disease

Multiple sclerosis (MS) is an inflammatory disease which exclusively affects the white matter of the central nervous system (CNS). Although there is a localized immune response within the CNS, immune abnormalities that correlate with disease activity are also found in the peripheral immune compartment of MS patients. These abnormalities primarily involve immunoregulatory defects in T-cell function that are associated with T- and B-cell hyperactivity. In this review, David Hafler and Howard Weiner discuss the evidence that there are T-cell abnormalities in MS similar to those observed in other autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis, and that the immunoregulatory defects in the blood of MS patients appear to be accompanied by the rapid migration of activated T cells from the peripheral blood to the CNS. That immunotherapy directed at the peripheral immune compartment affects the disease process supports their argument. Specifically, total lymphoid irradiation of the peripheral immune compartment ameliorates progressive MS whereas systemic treatment with IFN-gamma makes the disease worse. They conclude that the CNS inflammatory response is closely linked to, and in some ways dependent upon, the peripheral immune compartment.