Randomised double blind controlled trial of cyclosporin in multiple sclerosis

Optimization of a 40-mer Antimyelin DNA Aptamer Identifies a 20-mer with Enhanced Properties for Potential Multiple Sclerosis Therapy

We previously reported the in vitro selection and characterization of a DNA aptamer capable of stimulating remyelination in a mouse model of multiple sclerosis. This aptamer was selected for its ability to bind to suspensions of crude murine myelin in vitro. Our initial studies in vitro and in vivo involved a 40-nucleotide derivative (LJM-3064) of the original 100-nucleotide aptamer. LJM-3064 retained robust myelin-binding properties. Structural characterization of LJM-3064 revealed that the guanosine-rich 5' half of the sequence forms different G-quadruplex-type structures that are variably stable in the presence of physiologically relevant ions. We hypothesized that this structured domain is sufficient for myelin binding. In this study, we confirm that a 20-nucleotide DNA, corresponding to the 5' half of LJM-3064, retains myelin-binding properties. We then optimize this minimal myelin-binding aptamer via systematic evolution of ligands by exponential enrichment after sparse rerandomization. We report a sequence variant (LJM-5708) of the 20-nucleotide myelin-binding aptamer with enhanced myelin-binding properties and the ability to bind cultured human oligodendroglioma cells in vitro, providing the first evidence of cross-species reactivity of this myelin-binding aptamer. As our formulation of DNA aptamers for in vivo remyelination therapy involves conjugation to streptavidin, we verified that the myelin-binding properties of LJM-5708 were retained in conjugates to avidin, streptavidin, and neutravidin. DNA aptamer LJM-5708 is a lead for further preclinical development of remyelinating aptamer technologies.

Intrathecal IgG synthesis: a resistant and valuable target for future multiple sclerosis treatments

Intrathecal IgG synthesis is a key biological feature of multiple sclerosis (MS). When acquired early, it persists over time. A growing body of evidence suggests that intrathecal Ig-secreting cells may be pathogenic either by a direct action of toxic IgG or by locally secreting bystander toxic products. Intrathecal IgG synthesis depends on the presence of CNS lymphoid organs, which are strongly linked at anatomical level to cortical subpial lesions and at clinical level to the impairment slope in progressive MS. As a consequence, targeting CNS lymphoid lesions could be a valuable new target in MS, especially during the progressive phase. As intrathecal IgGs are end-products of these lymphoid lesions, intrathecal IgG synthesis may be considered as a specific marker of the persistence of these inflammatory lesions. Here we review the effect upon intrathecal IgG synthesis of all drugs ever used in MS. Except for steroids, all these therapeutic strategies, including rituximab, failed to decrease intrathecal IgG synthesis, with the exception of a questionable incomplete action of natalizumab. Thus, IgG synthesis is a robust marker of persistent intrathecal inflammation and its complete normalization should be one of the goals in future therapeutic strategies.

T-cell-specific deletion of STIM1 and STIM2 protects mice from EAE by impairing the effector functions of Th1 and Th17 cells

T-cell function is dependent on store-operated Ca(2+) influx that is activated by the stromal interaction molecules (STIM) 1 and 2. We show that mice with T-cell-specific deletion of STIM1 or STIM2 are protected from EAE, a mouse model of multiple sclerosis (MS). While STIM1- and STIM2-deficient T cells could be successfully primed by autoantigen, they failed to produce the proinflammatory cytokines IL-17 and IFN-γ. STIM1-deficient T cells showed reduced expression of IL-23R, required for Th17 cell homeostasis, and had impaired chemokine-dependent T-cell migration caused by a lack of chemokine-induced Ca(2+) influx. Autoantigen-specific STIM1- or STIM2-deficient T cells failed to expand and accumulate in the CNS and lymph nodes following adoptive transfer to passively induce EAE, suggesting that autoantigen-specific restimulation or homeostasis of STIM1- and STIM2-deficient T cells are impaired. Combined deletion of both STIM1 and STIM2, previously shown to impair Treg development and function, completely protected mice from EAE. This indicates that, in the absence of Ca(2+) influx, autoreactive T cells are severely dysfunctional rendering Treg dispensable for the prevention of CNS inflammation. Our findings demonstrate that both STIM1 and STIM2 are critical for T-cell function and autoimmunity in vivo.

Relapsing-remitting multiple sclerosis: what is the potential for combination therapy?

Multiple sclerosis is now a treatable disease and several immunomodulating therapies exist, but their clinical efficacy is moderate and treatment failure during the course of the disease is an increasing problem. As agents with different targets are available, the question was raised whether combination of these therapies would: be safe;result in reduction of adverse effects; andprovide synergistic benefit by additive or complementary modes of action. The areas under clinical investigation are general immunosuppression as well as more targeted approaches that interfere with antigen presentation, immune cell transmigration, release of myelinotoxic factors or even axonal damage. Combination of these immunomodulatory drugs seems to be rational and promising. Nevertheless, combination therapies need to be studied in carefully designed clinical trials in selected patient populations in order to demonstrate additive or synergistic effects. This article will summarise current drug combination strategies in relapsing-remitting multiple sclerosis and provide an overview of the initial clinical trials.

Effect of cyclosporine on blood pressure

BACKGROUND

Cyclosporine is an immunosuppressive agent used for different autoimmune diseases. The official Canadian indications for cyclosporine are solid organ transplantation, bone marrow transplantation, psoriasis, rheumatoid arthritis and nephritic syndrome (e-CPS 2008). The expanding range of indications for cyclosporine therapy will lead to more patients receiving chronic therapy with possible side effects, hypertension being one of the most common. Therefore it is essential to know the magnitude of increase of blood pressure (BP) associated with cyclosporine in order to appropriately manage patients receiving the drug.

OBJECTIVES

The primary objective of this systematic review is to evaluate the effect of cyclosporine on blood pressure, compared to placebo in randomized trials.

SEARCH STRATEGY

We searched The Cochrane Central Register of Controlled Trials (CENTRAL) and bibliographic databases, including MEDLINE (2000-2008) and EMBASE (1980-2008).

SELECTION CRITERIA

Selection was made using double-blind, randomized, controlled trials comparing cyclosporine to placebo. All patients treated with cyclosporine were included without restriction by type of disease or by age and sex.

DATA COLLECTION AND ANALYSIS

Blood pressure measurements in any setting and by any means were acceptable including the auscultatory or oscillometric method with a preference for the sitting position. Mean blood pressure results were entered as mean change from placebo and standard error of the mean (SEM). If blood pressure data was provided at different times after the initiation of cyclosporine therapy the weighted mean BP change from placebo from all measurements was used.

MAIN RESULTS

The search yielded 1340 citations, of which 17 trials met the inclusion criteria. We created dose-ranges according to the usual dose administration recommended by the manufacturer and allocated the 17 included trials to the corresponding dose-range. The results demonstrate a highly statistically significant increase in blood pressure associated with cyclosporine. There appears to be a dose-related effect with lower doses (1-4 mg/kg/d) increasing mean BP by an average of 5 mmHg and higher doses (>10 mg/kg/d) increasing mean BP by 11 mmHg on average. Furthermore in 3 trials the effect appears to be similar after a single dose as with chronic therapy.

AUTHORS' CONCLUSIONS

Cyclosporine statistically significantly increases blood pressure compared to placebo in a dose-related fashion. The magnitude of increase in blood pressure is clinically significant and increases the risk of stroke, myocardial infarction, heart failure and other adverse cardiovascular events associated with elevated BP. Consequently prescribers should try to find the lowest effective dose in all patients receiving cyclosporine chronically.

Novel insights in the immune function of the vitamin D system: synergism with interferon-beta

The 1,25(OH)(2)D(3) analog, TX527 (19-nor-14,20-bisepi-23-yne-1,25(OH)(2)D(3)), has an interesting dissociation profile between its potent immunomodulatory and its calcemic effects in vivo. The strong immunomodulatory potency of TX527 is reflected by its ability to attenuate experimental autoimmune encephalomyelitis (EAE), a murine model of multiple sclerosis (MS). At present most MS patients are being treated with systemic IFN-beta administration. The aim of this study was to investigate whether combining IFN-beta with TX527 could empower its EAE-protective effects. We evaluated also combinations with the standard immunosuppressant cyclosporin A (CsA). EAE was induced in SJL mice by PLP immunization, treatment was started 3 days before disease induction. The TX527+IFN-beta combination resulted in significant disease protection which was superior to the effect of both treatment separately. No disease amelioration, even aggravation, was obtained with the IFN-beta+CsA combination. By adding TX527 to the IFN-beta+CsA combination near complete protection from EAE was achieved (100% protection from paralysis, mean maximal score of 1.8+/-1.5, both p<0.05 versus controls and all individual treatments). From these data we conclude that adding TX527 to an IFN-beta and/or CsA treatment results in clear additional immunomodulatory effects in EAE prevention and is therefore a potentially interesting candidate to be considered in clinical intervention trials in MS.

Childhood multiple sclerosis: a review

Multiple sclerosis (MS) is an autoimmune demyelinating disorder of the central nervous system (CNS) that is increasingly recognized as a disease that affects children. Similar to adult-onset MS, children present with visual and sensory complaints, as well as weakness, spasticity, and ataxia. A lumbar puncture can be helpful in diagnosing MS when CSF immunoglobulins and oligoclonal bands are present. White matter demyelinating lesions on MRI are required for the diagnosis; however, children typically have fewer lesions than adults. Many criteria have been proposed to diagnose MS that have been applied to children, mostly above 10 years of age. The recent revisions to the McDonald criteria allow for earlier diagnosis, such as after a clinically isolated event. However, children are more likely than adults to have monosymptomatic illnesses. None of the approved disease-modifying therapies used in adult-onset MS have been approved for pediatrics; however, a few studies have verified their safety and tolerability in children. Although children and adults with MS have similar neurological symptoms, laboratory (cerebrospinal fluid) data, and neuroimaging findings, the clinical course, pathogenesis, and treatment of childhood onset MS require further investigation.

B cells in the pathophysiology of autoimmune neurological disorders: A credible therapeutic target

There is evidence that B cells are involved in the pathophysiology of many neurological diseases, either in a causative or contributory role, via production of autoantibodies, cytokine secretion, or by acting as antigen-presenting cells leading to T cell activation. Clonal expansion of B cells either in situ or intrathecally and circulating autoantibodies are critical elements in multiple sclerosis (MS), Devic's disease, paraneoplastic central nervous system disorders, stiff-person syndrome, myasthenia gravis, autoimmune demyelinating neuropathies and dermatomyositis. The pathogenic role of B cells and autoantibodies in central and peripheral nervous system disorders, as reviewed here, provides a rationale for investigating whether depletion of B cells with new agents can improve clinical symptomatology and, potentially, restore immune function. Preliminary results from several clinical studies and case reports suggest that B cell depletion may become a viable alternative approach to the treatment of autoimmune neurological disorders.

A novel nitric oxide scavenger in combination with cyclosporine A ameliorates experimental autoimmune encephalomyelitis progression in mice

Immunotherapy improves experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS), while excessive production of nitric oxide (NO) has been implicated in the pathogenesis of this disease. Here, we show that disease progression in SJL/J mice with EAE is improved after treatment with either a subtherapeutic dose of cyclosporine A (CsA) or NOX-100, a nitric oxide scavenger. Importantly, the impact of subtherapeutic doses of CsA in combination with NOX-100 on disease progression in EAE was greater than that attained with either agent alone and led to near total protection. CNS inflammation and gene expression of proinflammatory cytokines and iNOS were also significantly reduced after treatment. These observations point to the potential therapeutic utility of NOX-100 as a dose-reducing agent for CsA in the treatment of MS.

Consenso expandido do BCTRIMS para o tratamento da esclerose múltipla: I. As evidências para o uso de imunossupressores, plasmaférese e transplante autólogo de células tronco

O tratamento da esclerose múltipla (EM) com imunossupressores teve início na década de 60. As observações laboratoriais e clínicas de que a doença tinha um caráter inflamatório induziu os clínicos a utilizarem medicamentos citostáticos e imunossupressores. Foram assim incorporados ao arsenal terapêutico da EM as drogas utilizadas em outras doenças inflamatórias sistêmicas como a artrite reumatóide e o lupus eritematoso sistêmico. As drogas imunossupressoras mais utilizadas são a ciclofosfamida, azatioprina e o metotrexate. A ciclosporina e a cladribina foram utilizadas mais recentemente para o controle da EM na forma recorrente-remitente (RR). O mitoxantrone foi aprovado pelo FDA em 2000 para as formas mais agressivas, tanto RR, como secundariamente progressiva (SP) ou primariamente progressiva (PP). Outras formas de tratamento como plasmaférese e transplante autólogo de células tronco (TACT), foram inseridas neste arsenal terapêutico com suas características específicas e para casos especiais.

Multiple Sclerosis: Immunotherapy

Given our current knowledge, there is a need for the early institution of immunomodulatory therapy, especially for patients with poor prognostic factors (motor and cerebellar symptoms, frequent disease exacerbations, and a high level of activity on magnetic resonance imaging ). Patients who progress despite immunomodulatory therapy should be reevaluated in terms of diagnosis, development of neutralizing antibodies, or compliance. If a patient has a partial response to immunomodulatory therapy but his or her disease, as assessed by clinical and MRI criteria, remains very active, every effort should be made to modify disease progression by searching for an immunosuppressive therapy regimen before irreversible and considerable disability has accumulated. For the majority of patients, multiple sclerosis (MS) is a chronic condition. Therefore, until a curative treatment has been developed, the available repertoire of immunosuppressive or immunomodulatory treatments should be assessed with respect to the possibility of long-term use. This is particularly important for new immunosuppressive drugs, such as cladribine or mitoxantrone, or for invasive procedures, such as total lymphoid irradiation or autologous bone marrow transplantation. For the latter treatments, experience with long-term administration is not available or the potential side effects (eg, cardiotoxicity with mitoxantrone) limit the cumulative dose. These considerations may limit long-term administration and thus the general usefulness of some drugs. Even with proven efficacy, we need to define the next step once treatment has to be discontinued. We should also address whether exacerbating disease by discontinuing an effective therapy is a potential hazard. What other therapeutic options remain once the current treatment is discontinued? Answers are not readily available at the moment, but the question should influence our decisions in the selection of traditional, well-studied or new, potentially promising therapies.

Recent developments in drug therapy for multiple sclerosis

Symptomatic treatment of multiple sclerosis (MS) includes a diverse range of drugs intended to relieve the specific symptoms with which a patient may present at a particular point in the progression of the disease. These drugs, not specifically designed for the treatment of MS, may include antispastic agents (e.g. baclofen), drugs to reduce tremor (e.g. clonazepam), anticholinergics (e.g. oxybutynin) which relieve urinary symptoms, anti-epileptics (e.g. carbamazepine) to control neuralgia, stimulants to reduce fatigue (e.g. amantadine), and antidepressants (e.g. fluoxetine) to treat depression. The treatment of acute relapses or exacerbations is dominated by corticosteroids such as methylprednisolone. The most active area of current investigation is the development of drugs which will inhibit the progression of the disease process itself, and in this category the beta- and alpha-interferons are the most effective drugs currently available, although many new treatments are currently in trials, including immunoglobulin, copolymer-1. bovine myelin, T-cell receptor (TCR) peptide vaccines, platelet activating factor (PAF) antagonists, matrix metallo-proteinase inhibitors, campath-1, and insulin-like growth factor (IGF).

Disease activity and the immune set in multiple sclerosis: blood markers for immunotherapy

There is no established immunological marker of multiple sclerosis activity, which reflects the poor understanding of the immunopathogenesis of multiple sclerosis. Passive measurement of the levels of soluble inflammatory markers, whose half lives are usually measured in minutes and hours, can only indicate the extent of instantaneous inflammation, which is known to fluctuate in multiple sclerosis. We favour measurement of immune responses in vitro. As healthy individuals have T cell reactivities to myelin proteins that are postulated to be pathogenic in multiple sclerosis, we prefer non-antigen specific mitogen and recall antigen assays as immunological markers. We illustrate their use in the treatment of 27 patients with multiple sclerosis using a pulse of humanised anti-lymphocyte (CD52) antibody that caused prolonged T cell depletion. The mitogen-induced proliferation, and secretion of IFN-gamma, from peripheral blood mononuclear cells in vitro was significantly reduced after treatment, suggesting that immune responses had been modulated. Such observations will only gain credence as an outcome measure if they are shown to correlate with clinical or radiological measures of multiple sclerosis activity. Perhaps more importantly, aspects of the pathogenesis of multiple sclerosis may be revealed by close immunological surveillance of patients undergoing experimental treatments.

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.

Synergism between sirolimus and 1,25-dihydroxyvitamin D3 in vitro and in vivo

The active form of vitamin D, 1 alpha, 25-(OH)2D3, displays immunomodulatory effects in vitro and in vivo at pharmacological levels. We evaluated the dose-effect relationship of 1,25(OH)2D3 and sirolimus (rapamycin, RAP) in vitro, on the inhibition of PHA-stimulated PBMC proliferation, by using the median effect analysis. Pharmacological concentrations of 1,25(OH)2D3 (between 10(-9) and 3 x 10(-6) M) interacted synergistically with RAP (combination index value of 0.01 for 50% suppression of PBMC proliferation). In vivo, the effect of 1,25(OH)2D3 and RAP combinations on the evolution of experimental allergic encephalomyelitis in SJL mice was analyzed. 1,25(OH)2D3, given i.p., in monotherapy, at a dose of 2 micrograms/kg every two days, from day -3 until day +19 after disease induction, or RAP, injected daily at a dose of 0.3 mg/kg for the same period, decreased EAE incidence (paralysis in 70 and 55% of the animals, respectively, versus 98% in the placebo treated group, p < 0.001). The combination treatment using the two drugs in these subtherapeutical doses provided near-total clinical (8% paralysis, p < 0.001 compared to monotherapy with 1,25(OH)2D3 or RAP) and histological protection, comparable to that obtained with RAP in monotherapy at a threefold higher dose (1 mg/kg/d). When the two drugs were given using an alternate day administration schedule (RAP at 0.6 mg/kg and 1,25(OH)2D3 at 2 micrograms/kg, each given on alternate days from day -3 to 19), near total protection was again obtained (13% paralysis, p < 0.001 versus control). These in vitro and in vivo data support the existence of synergistic interactions between 1,25(OH)2D3 and RAP. Considering the narrow therapeutic windows of both RAP and vitamin D-related compounds in autoimmune disease models, combinations of these drugs could find clinical application in reducing their individual therapeutically efficient doses to non-toxic levels.

In vitro modulation of human, autoreactive MBP-specific CD4 + T-cell clones by cyclosporin A

Cyclosporin A (CsA) is a potent immunosuppressant affecting many components of cellular and humoral immunity. Its main action probably results from inhibition of T-lymphocyte activation and interference with secretion of cytokines like IL-2, IL-4, IFN-gamma and TNF-alpha. Correspondingly, CsA has beneficial effects on the course of several autoimmune diseases thought to be mediated by T-lymphocytes, including a mild effect on multiple sclerosis. We exposed CD4 + cytotoxic T-lymphocytes specific for myelin basic protein, a putative target autoantigen in MS, to CsA in vitro, and determined the drug's effects on proliferation, expression of high affinity IL-2R, secretion of the proinflammatory cytokines IFN-gamma and TNF-alpha as well as on the secretion of the chemokines MIP-1 alpha and MIP-1 beta. In all instances, we observed a partial to complete inhibition. In contrast, the response of activated cells to IL-2 was resistant to CsA. Our observations are in line with results obtained in different experimental systems. The discrepancy between the profound inhibition of T-cells and the modest therapeutic effects on MS is discussed.

Cyclosporin and plasmapheresis in treatment of progressive systemic lupus erythematosus (pSLE)

The prognosis of patients suffering from progressive systemic lupus erythematosus (pSLE) is poor, despite treatment with intensive drug regimens with combinations of corticosteroids, azathioprine and cyclophosphamide. Side-effects such as infections and malignomas often occur. In the present trial, 21 patients (four male, 17 female, aged 37.9 +/- 12.8) suffering from pSLE for 9.4 +/- 2.6 years, were treated for 2.3 +/- 1.8 years with drug regimens as mentioned above. Then, over a period of 6.4 +/- 2.6 (range 1-8) years, in addition to conventional therapies, cyclosporin (2.5 +/- 0.6 mg/kg body wt/d) and, in active stages of the disease with extremely high concentrations of anti-ds-DNA-, anti-nuclear antibodies and circulating immunocomplexes, plasmapheresis (therapeutic plasma exchange (TPE)) have been applied. Compared with previous treatment modalities, significantly (P < 0.05) more effective and rapid reduction of antibodies was achieved. Clinical symptoms improved within 2 to 4 weeks. Under the new therapeutic regimen all patients reported increased performance and a better quality of life. After 5 to 48 (17.5 +/- 13.8) months, cyclosporin was established as mono-therapy for 8/21 patients. In] the other cases, corticosteroids, azathioprine and cyclophosphamide were reduced by 40 to 100%. No severe side-effects were seen. In acute stages of pSLE and in forms with persistently high antibody levels, the addition of TPE to conventional therapy was very effective, with regard to improving both clinical and laboratory parameters.

Investigational drug therapies of treatment of multiple sclerosis

The licensing of interferon beta-1b dramatically changed the treatment of multiple sclerosis (MS) in the United States. Although it was the first therapeutic agent shown to affect the natural course of the disease, interferon beta-1b is not appropriate for all patients and is far from being a cure. Several other promising therapies now under study include immunosuppressive and immunomodulatory drugs to limit inflammation; oral administration of myelin to induce tolerance; monoclonal antibodies designed to deliver targeted immunotherapy; potassium channel blockers to facilitate conduction along demyelinated axons; and glial growth factors to promote remyelination. Clinical trials of potential therapeutic agents have proliferated in the past decade in conjunction with rapid advances in our understanding of the immunologic basis of MS. Some investigational therapies are associated with problematic toxicities, others benefit only a minority of patients, and many are still in the early stages of development. Nevertheless, because current therapeutic options are limited, and because the history of MS therapy is one of disappointment and frustration, it is essential that legitimate, scientifically based advances be widely disseminated to the neurologic community. This article reviews some of the most promising current and investigational therapies for MS.

Introductory remarks: immunosuppressive and immunomodulating drugs, where and how do they act?

Immunotherapies used in multiple sclerosis are reviewed. The mechanisms of action supporting their clinical application are described according to our current understanding. Immune treatments can be divided into three groups: (1) cytostatic and cytotoxic immunosuppressants which block the cell cycle of immunocompetent cells and/or provoke their deletion; (2) immunomodulators which specifically interfere in cellular or humoral immune mechanisms; (3) immunoregulators which restore immunodeficient states but have also immunosuppressive properties at the same time. Numerous attempts have been made to correct almost all abnormal immune mechanisms underlying disease progression. The results of those clinical trials are reviewed. Recent studies have demonstrated that a severe, unspecific and sustained immunosuppression markedly downregulates the clinical and pathological activity of the disease. Unfortunately, serious delayed adverse effects prevent a long-term administration. Recent specific immunomodulators with an acceptable toxicity have provided modest but unquestionable benefit on the attack rate and MRI lesion burden. No clear effect on progression has been demonstrated to date. There is still much work to be done to improve the efficacy of our current therapies on the attack rate and particularly on the progression. Several promising new compounds are already under evaluation. Another approach is combination therapies which will certainly become critical in MS like in other autoimmune diseases.

Combinations of drugs

As a result of recent therapeutic trials, recombinant Interferon beta (rIFN beta)-Ib and -Ia as well as Copolymer I (COP I) and to some extent unspecific immunosuppressants have been accepted as partially efficient treatments of relapsing-remitting MS. In view of partially effective single treatments, the question arises if combination of two or even more-agents could improve efficacy without increasing side effects. The theoretical background of possible combinations is discussed. The selection of combination partners should be based on their proven efficacy as single treatment, on their mode of action and their distinct target in the pathogenetic cascade of events and on their specific side effect profile. Combination regimens selected in this way should undergo evaluation in short term early phase II studies and if the results are positive enter phase III studies. The use of surrogate markers (especially MRI-findings) may help to accelerate this process. Combinations that could enter phase II and III studies in the near future are rIFN beta with unspecific immunosuppressants, e.g. Azathioprine or Methotrexate and rIFN beta with COP I. Combinations including agents just entering phase I and II studies as a single treatment may be more promising for the future.

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.

Inhibition of blood-brain barrier disruption in experimental allergic encephalomyelitis by short-term therapy with dexamethasone or cyclosporin A

Double radioisotope measurement of neurovascular integrity in Lewis rats inoculated for experimental allergic encephalomyelitis (EAE) showed abnormal elevation of albumin extravasation in the cerebellum, medulla-pons and cervical spinal cord at the time of clinical manifestation. Therapeutically administered dexamethasone (Dex) (0.1-1 mg/kg body weight) or cyclosporin A (CsA) (25-75 mg/kg body weight) dose-dependently reduced albumin movement across the blood-brain barrier (BBB). Dex at a dose of 1 mg/kg completely suppressed abnormal BBB permeability in all tissues (P < or = 0.001), while CsA at the highest dose of 75 mg/kg achieved highly significant (P < or = 0.001), but not complete, suppression of aberrant barrier leakage in the areas studied. The implications of these findings to possible drug action at the immunocompromised cerebrovasculature are discussed.

Multiple sclerosis therapy. A practical guide

A growing amount of evidence suggests that a disturbance of immunological function is of importance in the pathogenesis of multiple sclerosis. This is reflected in the drugs used to slow progression and to treat relapses. Immunosuppressive drugs such as azathioprine, cyclophosphamide and cyclosporin might have some potential to slow down progression of multiple sclerosis, but their use is limited by potentially serious adverse effects. Recently, it was shown that interferon-beta-1b can diminish the exacerbation rate in multiple sclerosis without leading to unacceptable adverse effects. Nevertheless, symptomatic treatment remains of crucial importance in the management of multiple sclerosis patients. Spasticity, depression, fatigue and urinary, paroxysmal and sensory symptoms can all be alleviated to some extent with pharmacological interventions, although rehabilitation procedures and psychosocial consultations are no less important. Further therapeutic approaches to multiple sclerosis will be directed at either the specificity of the immune response or the grade of activation of the immune response. Magnetic resonance imaging techniques will play an important role in the evaluation of efficacy of new therapeutic agents.

On the pathogenesis of multiple sclerosis. A revised model of the cause(s) of multiple sclerosis, especially based on epidemiological data

Data from an epidemiological study are used to analyse the course of multiple sclerosis. It could be proved that the course of MS is not as haphazard as was often supposed. In general the course is described as being a chronic progressive one, in the majority of patients preceded by a relapsing-remitting period. In contrast to the relapsing-remitting phase the chronic progressive phase of the course does not show marks of being an autoimmune process. From recent data obtained by MRI and NMR spectroscopy it can be concluded that the chronic progression of handicaps in multiple sclerosis is related to neuronal and axonal damage. The relation between these different pathogenetic processes should be the aim of further research.

A placebo-controlled trial of isoprinosine in patients with multiple sclerosis

Isoprinosine was used under double-blind, randomised, and placebo-controlled conditions in 52 patients with relapsing/remitting or progressive multiple sclerosis. All patients received pulsed treatment with methylprednisolone. There was no significant effect of treatment on clinical disability or the accumulation of MRI abnormalities, after correction of results for multiple comparisons. It is concluded that isoprinosine is not effective therapy for multiple sclerosis.

Total lymphoid irradiation in multiple sclerosis

Following a report of the efficacy of total lymphoid irradiation (TLI) in the treatment of chronic progressive multiple sclerosis a further randomised double-blind placebo-controlled study was undertaken with the intention of entering 56 patients. In the event it was possible to recruit only 27 patients in a 2.5 year period. Three patients received active treatment openly and 24 were randomised to either active (14) or sham (10) treatment. Treatment was 1980 cGy to the lymphoid system and spleen or sham treatment after full simulation. The primary outcome measure was a comparison of the mean rates of change between treatment groups on the expanded Kurtzke disability scale (EDSS) over the two year follow up period. Patients were also assessed on other clinical outcome measures, psychometry, and serial MRI of the brain. Active treatment resulted in a profound and prolonged fall in T lymphocytes especially those with the CD4 marker and a reversal in CD4:CD8 ratio. No significant benefit was demonstrated on the rate of clinical disease progression (EDSS). A small but significant benefit was found on a score of bladder function. No significant benefit was demonstrated on other clinical or psychometric indices or on subjective visual analogue scales. There was a small but significant difference in the rate of accumulation of lesions on brain MRI favouring the treatment group. The treated group had a higher incidence of clinically relevant side effects, notably amenorrhoea and infections: three deaths (one in the TLI group, two in the sham treated group) occurred. A post hoc calculation indicates that the study had a possible 35% risk of a false negative result using the principal outcome measure. The study fails to confirm the previously reported clinical benefit of TLI although there may be a minor benefit on disease progression as indicated by MRI lesion counts. It is concluded that TLI cannot be recommended for the routine treatment of chronic progressive multiple sclerosis but the beneficial effect on MRI lesions, though modest, suggests that further research into immune modulation of this condition may be worthwhile.

Cyclosporin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic use in immunoregulatory disorders

Cyclosporin is a lipophilic cyclic polypeptide which produces calcium-dependent, specific, reversible inhibition of transcription of interleukin-2 and several other cytokines, most notably in T helper lymphocytes. This reduces the production of a range of cytokines, inhibiting the activation and/or maturation of various cell types, including those involved in cell-mediated immunity. Thus, cyclosporin has immunosuppressive properties, and has a proven place as first line therapy in the prophylaxis and treatment of transplant rejection. Cyclosporin has also been evaluated in a large range of disorders where immunoregulatory dysfunction is a suspected or proven aetiological factor, and this is the focus of the present review. In patients with severe disease refractory to standard treatment, oral cyclosporin is an effective therapy in acute ocular Behçet's syndrome, endogenous uveitis, psoriasis, atopic dermatitis, rheumatoid arthritis, active Crohn's disease and nephrotic syndrome. Concomitant low dose corticosteroid therapy may improve response rates in some disorders. The drug can be considered as a first line therapy in patients with moderate or severe aplastic anaemia who are ineligible for bone marrow transplantation, with the additional benefit of reducing platelet alloantibody titres. It may also be of considerable therapeutic benefit in patients with primary biliary cirrhosis, particularly those with less advanced disease. Limited evidence suggests cyclosporin is effective in patients with intractable pyoderma gangrenosum, polymyositis/dermatomyositis or severe, corticosteroid-dependent asthma. Indeed, the steroid-sparing effect of cyclosporin is a significant advantage in a number of indications. Furthermore, the drug has shown some efficacy in a wide range of other, generally uncommon disorders in which controlled clinical trials are lacking and/or are unlikely to be performed. Cyclosporin does not appear to be effective in patients with allergic contact dermatitis, multiple sclerosis or amyotrophic lateral sclerosis. It is only temporarily effective in patients with type I (insulin-dependent) diabetes mellitus and should not be used in this indication. To avoid relapse after control of active disease, patients should receive cyclosporin maintenance therapy at the lowest effective dosage. However, maintenance therapy appears to be of no benefit in patients with Crohn's disease and cyclosporin should be discontinued in these patients once active disease is controlled. Hypertrichosis, gingival hyperplasia, and neurological and gastrointestinal effects are the most common adverse events in cyclosporin recipients, but are usually mild to moderate and resolve on dosage reduction. Changes in laboratory variables indicating renal dysfunction are relatively common, although serious irreversible damage is rare.(ABSTRACT TRUNCATED AT 400 WORDS)

Control of immune-mediated disease of the central nervous system with monoclonal (CD4-specific) antibodies

Chronic relapsing experimental allergic encephalomyelitis (CREAE) was induced in Biozzi AB/H (H-2dq1) mice by active sensitization with spinal cord antigens. A single i.p. injection of CD8-depleting (YTS169.4) monoclonal antibody (mAb) failed to affect the clinical course of CREAE when administered prior to and during the onset of both the initial clinical and subsequent relapse phase of the disease. By contrast similar treatment with both CD4-depleting (YTS191.1) or CD4-blocking/non-depleting (YTS177.9) mAb significantly inhibited disease progression. Treatment shortly before the anticipated onset of clinical EAE prevented the subsequent development of disease, although disease could be provoked following antigen-rechallenge. In contrast, treatment with these antibodies during post-acute remission phase mainly served to delay the incidence of relapse. This suggests that, unless tolerance can be re-induced, treatment of ongoing neuroimmunological disease will require 'pulse' therapy and thus potentiate the problems of long-term immunosuppresion. Despite the findings that CD4-specific antibodies can rapidly reverse overt clinical disease shortly after the onset of disease exacerbation, once neurological dysfunction becomes established anti-CD4 treatment fails to improve the animals clinically, possibly due to the inability to rapidly reverse established demyelination. Although this study does not exclude the potential central action of the injected mAb, the failure to significantly dissociate therapeutic benefit between mAb administered directly into the CNS and that given systemically suggests that a major action of these agents is probably by selectively removing T cells in the peripheral T cell pool.

Update on multiple sclerosis therapy

Multiple sclerosis is a demyelinating disorder of the central nervous system characterized by exacerbations and remissions of symptoms. This article deals with symptomatic therapy involving treatment of spasticity, fatigue, neurobehavioral disorders, paroxysmal disorders, pain, bladder dysfunction, and cerebellar dysfunction. This article also reviews immunosuppressive therapies including treatment of acute exacerbations or overall progression of the disorder with resultant accumulation of disability.

The dynamics of multiple sclerosis. The Charcot Lecture

The history of our understanding of the pathogenesis and pathophysiology of multiple sclerosis are reviewed in the context of Charcot's contribution. The implications for treatment of the new knowledge gained from studies during life of pathology and pathogenesis (by MRI) and pathophysiology (by evoked potentials) are reviewed.

[Immunosuppressive treatment in multiple sclerosis]

An open, retrospective, uncontrolled study was carried out to evaluate efficacy and tolerability of immunosuppressive therapy used in the period 1982-1990 in patients with clinically definite multiple sclerosis. Of 42 patients 43% were treated with one drug, and the others with more than one. Tolerability was evaluated after at least 6 months of therapy in 6 patients on prednisone, 26 on azathioprine, 17 on methyl-prednisolone and 15 on cyclophosphamide pulses. Reversible mild or moderate side-effects were noted in 54% of the patients on azathioprine, leading to change in dose or withdrawal. There were similar side-effects in 83% of the patients on prednisone, 40% of those on cyclophosphamide, and in 12% of those on methylprednisolone. Efficacy was evaluated in 15 patients with a follow-up of at least 2 years, measured by objective scales. The results indicated therapy appeared to arrest progress of disability. We conclude that this study supports the use of immunosuppression in selected cases with rapidly evolving neurological deficits.

Experimental autoimmune uveoretinitis (EAU) versus experimental allergic encephalomyelitis (EAE): a comparison of T cell-mediated mechanisms

EAU is a model of ocular inflammatory disease. EAU resembles another T cell-mediated autoimmune disease--experimental allergic encephalomyelitis--since both have increased expression of MHC class II molecules in the target tissue, can be adoptively transferred by activated CD4+ T cells and are inhibited by cyclosporin A. The immunological findings will be compared to find out if the same cellular mechanisms are involved in both diseases.

Therapy of chronic relapsing experimental allergic encephalomyelitis and the role of the blood-brain barrier: elucidation by the action of Brequinar sodium

The immunosuppressive effect of the novel 4-quinoline carboxylic acid derivative Brequinar sodium on the chronic relapsing experimental allergic encephalomyelitis CREAE model in the Biozzi AB/H mouse was investigated. Although Brequinar sodium actively inhibited peripheral immune responses, it showed a limited potential to control an ongoing disease of the central nervous system (CNS). Doses of 25 mg/kg inhibited in vivo induced proliferative response and prevented EAE when treated from day 9 post-inoculation (p.i.). However, when administered from day 12 p.i. or during the post-acute remission phase-limited effects on the course of disease were observed. By comparison, treatment with a single high dose of cyclophosphamide (200 mg/kg) at these time points was significantly effective in controlling disease. As a possible explanation of the observed results it is suggested that for a compound to be effective in treating an ongoing immune response in the CNS, it must be capable of crossing the blood-brain barrier and act on the disease-inducing cells activated within the CNS. This hypothesis is supported by the finding that intracerebral injections of Brequinar sodium on day 12 p.i. significantly inhibited disease progression. This suggests that strategies aimed at controlling immune-mediated disease of the CNS require therapeutic doses of the compounds to be delivered into the CNS.

Immunointervention with cyclosporin A in autoimmune neurological disorders

Cyclosporin A has proven a remarkably effective compound in suppressing disease activity in a number of animal models of autoimmune neurological disorders. During the last decade a number of controlled clinical trials have been carried out in human neurological disorders which are considered to be immune-mediated. The results of those trials are reviewed.

The optimal use of cyclosporin A in autoimmune diseases

The optimal use of cyclosporin (CsA) in autoimmune diseases aims at achieving the best risk/benefit ratio and ensuring the absence of potentially irreversible adverse effects, particularly with respect to the kidney [corrected]. The experience gained with CsA therapy in more than 3,000 patients with autoimmune diseases is the basis for the current recommendations: the initial dose should be the lowest effective one and not exceed 5 mg/kg/day in non-life-threatening conditions; treatment should be as brief as possible (2-4 months) in cases of inefficacy; once a satisfactory clinical improvement has been achieved, the treatment should be maintained in the long-term using the lowest individually titrated effective dose; the dose of CsA should be decreased when serum creatinine rises by more than 30% above pre-CsA level. Continuous clinical and biological monitoring (especially of blood pressure and serum creatinine) is mandatory as long as CsA is prescribed. When these conditions are fulfilled, CsA may be an effective and safe therapy for selected autoimmune diseases, even in long-term treatment.

The efficacy of cyclosporin A, FK-506 and prednisolone to modify the adoptive transfer of experimental allergic encephalomyelitis (EAE)

The in vitro potency of the immunosuppressants Cyclosporin A (CsA), FK-506 and Prednisolone was assessed using the adoptive transfer model of EAE in the Lewis rat. Co-culture of encephalitogen-sensitised splenic leukocytes with Prednisolone did not inhibit the transfer of disease to naive histocompatible recipients despite significant suppression of neuroantigen-stimulated leukocyte proliferation by the drug. The addition of CsA (100 nM) to cultures inhibited the induction of adoptive EAE but a lower dose of the agent (10 nM) did not prevent the development of clinico-histopathological signs of disease. FK-506 (1 nM) was 100 times more effective than CsA at suppressing adoptive EAE thus emphasising the usefulness of the model in determining the relative efficacy of compounds to modify cell-dependent autoimmune disease.

Detection of nephrotoxicity in cyclosporine-A amyotrophic lateral sclerosis patients by means of urinary cytology

Exfoliative urinary cytology was used for two amyotrophic lateral sclerosis patients treated with 3 mg/kg/day cyclosporine (CsA) therapy in order to detect the onset of the nephrotoxic side-effects of the drug before the apparent deterioration of the patients' clinical condition. Of the two patients, only one showed clear morphological features of drug-related damage in a one year course of cyclosporine therapy, but these followed the increase in the serum kidney and liver laboratory parameters and did not prove useful for the early detection of nephrotoxicity. However, in this patient the renal damage was hallmarked by an increasing number of tubular cells or clusters of ill-defined renal cells in the urinary specimen, suggesting an ongoing tubular injury. The slight cytological alterations may possibly be due to the low CsA dosage used for these patients. The significance of these observations is tempered by the limited number of patients and specimens studied to date and further studies in nontransplanted patients are therefore advocated, particularly when higher CsA doses are employed.

Inhibition of chronic relapsing experimental allergic encephalomyelitis in the mouse by the alkyl-lysophospholipid ET-18-OCH3

The effect of the anti-tumour agent alkyl-lysophospholipid (ALP) ET-18-OCH3 on the development of chronic relapsing experimental allergic encephalomyelitis (CREAE) in the mouse was investigated. Experimental allergic encephalomyelitis developed in the majority (greater than 96%) of mice immunized with autologous spinal cord homogenate in Freund's complete adjuvant. Alkyl-lysophospholipid, in doses of 25 mg/kg/day or 50 mg/kg/day, inhibited the onset of clinical signs of acute phase CREAE when orally administered starting on the day of disease induction. Similarly if treatment with 50 mg/kg/day was delayed until day 9 post-inoculation the incidence of disease and severity of clinical signs were also significantly reduced (P less than 0.02) as compared with vehicle fed animals. However, when treatment began on day 12, just prior to the onset of clinical disease, although the incidence of disease was not significantly altered the severity of disease was significantly (P less than 0.002) reduced compared with vehicle treated animals. These data suggest that although the major effect of ALP is on the inhibition of the generation of the autoimmune response there appeared to be some therapeutic benefit at a later stage of acute disease. Therefore, this study was extended to the treatment of post-acute phase remission animals. It was found that the oral administration of 50 mg/kg/day marginally reduced and that 75 mg/kg/day significantly (P less than 0.05) reduced the incidence of relapsing disease compared with vehicle treated controls. This suggests that ET-18-OCH3 may have some potential in the treatment of ongoing autoimmune disease of the central nervous system.