Failure of intravenous immunoglobulin to arrest progression of multiple sclerosis: a clinical and MRI based study

Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disease of the central nervous system (CNS) characterized by loss of motor and sensory function that results from immune-mediated inflammation, demyelination, and subsequent axonal damage.

Clinically, most MS patients experience recurrent episodes (relapses) of neurological impairment, but in most cases (60–80%) the course of the disease eventually becomes chronic and progressive, leading to cumulative motor, sensory, and visual disability, and cognitive deficits.

The course of the disease is largely unpredictable and its clinical presentation is variable, but its predilection for certain parts of the CNS, which includes the optic nerves, the brain stem, cerebellum, and cervical spinal cord, provides a characteristic constellation of signs and symptoms. Several variants of MS have been nowadays defined with variable immunopathogenesis, course and prognosis. Many new treatments targeting the immune system have shown efficacy in preventing the relapses of MS and have been introduced to its management during the last decade.

Immunotherapy of multiple sclerosis: the state of the art

It is widely accepted that the main common pathogenetic pathway in multiple sclerosis (MS) involves an immune-mediated cascade initiated in the peripheral immune system and targeting CNS myelin. Logically, therefore, the therapeutic approaches to the disease include modalities aiming at downregulation of the various immune elements that are involved in this immunologic cascade. Since the introduction of interferons in 1993, which were the first registered treatments for MS, huge steps have been made in the field of MS immunotherapy. More efficious and specific immunoactive drugs have been introduced and it appears that the increased specificity for MS of these new treatments is paralleled by greater efficacy. Unfortunately, this seemingly increased efficacy has been accompanied by more safety issues. The immunotherapeutic modalities can be divided into two main groups: those affecting the acute stages (relapses) of the disease and the long-term treatments that are aimed at preventing the appearance of relapses and the progression in disability. Immunomodulating treatments may also be classified according to the level of the 'immune axis' where they exert their main effect. Since, in MS, a neurodegenerative process runs in parallel and as a consequence of inflammation, early immune intervention is warranted to prevent progression of relapses of MS and the accumulation of disability. The use of neuroimaging (MRI) techniques that allow the detection of silent inflammatory activity of MS and neurodegeneration has provided an important tool for the substantiation of the clinical efficacy of treatments and the early diagnosis of MS. This review summarizes in detail the existing information on all the available immunotherapies for MS, old and new, classifies them according to their immunologic mechanisms of action and proposes a structured algorithm/therapeutic scheme for the management of the disease.

IgG Fc receptor polymorphisms in human disease: implications for intravenous immunoglobulin therapy

Polymorphisms of human Fc receptors (FcRs) have been described that are associated with the development or progression of autoimmune diseases. The FcR polymorphisms affect the affinity with which FcRs interact with immunoglobulin molecules. Intravenous immunoglobulin is administered as therapy for many autoimmune diseases and might exert its effects by interacting with FcRs. Thus, FcR polymorphisms might influence the efficacy of intravenous immunoglobulin therapy for patients with certain autoimmune diseases. In this article we review FcR polymorphisms in relation to autoimmune diseases for which intravenous immunoglobulin is used therapeutically.

The role of intravenous immunoglobulin in the treatment of multiple sclerosis

Intravenous immunoglobulin (IVIG) has several effects on the immune system that could have a beneficial influence on disease processes in multiple sclerosis (MS). Owing to its anti-inflammatory properties, IVIG may be beneficial in the treatment of acute relapses and in prevention of new relapses. By promoting remyelination, IVIG could have a beneficial effect on disability and disease progression. Four double-blind trials in relapsing-remitting MS have demonstrated that IVIG reduces the relapse rate and the number of gadolinium enhancing lesions, and in this respect seems comparable to established therapies in relapsing-remitting MS, i.e. interferon-beta and glatiramer acetate. The doses of IVIG that have been used for treatment in relapsing-remitting have varied 10-fold, and the ideal dosage of IVIG for treating MS still needs to be determined. Three studies have been performed to assess the effect of IVIG on chronic visual impairment or established motor symptoms in MS. None of these trials could confirm that established symptoms in MS can be reversed by IVIG. In secondary progressive MS, a large randomized placebo-controlled trial has recently shown that IVIG is without beneficial effects in this phase of the disease. In conclusion, IVIG is a valuable alternative for treatment of relapsing-remitting MS in patients who do not tolerate or are unwilling to take the approved injectable medications, but additional studies are needed to establish the role of IVIG in the management of multiple sclerosis.

Primary progressive multiple sclerosis: increasing clarity but many unanswered questions

Heterogeneity in the clinical course of multiple sclerosis (MS) is well recognised and patients following a primary progressive course, 10-15% of the MS population, have a distinct clinical and paraclinical phenotype. This review examines recent advances in our understanding of this subgroup of patients and examines the new criteria to be applied in diagnosis. It also highlights developments in genetic, immunological, magnetic resonance and pathological aspects of the disease, whilst also outlining the results of recent therapeutic trials.

Glatiramer acetate in the treatment of multiple sclerosis

This review article summarises the initial preclinical studies as well as the different stages of clinical trials in multiple sclerosis (MS) with Copolymer 1 (Cop 1), recently denoted glatiramer acetate. Experimental studies on autoimmune encephalomyelitis (EAE), the animal model of MS, as well as studies on the mechanism of action in both animals and humans are discussed. The review describes the early clinical trials which were followed by Phase II and III trials, culminating in FDA approval in 1996 for the treatment of relapsing-remitting MS. The accumulated experience with glatiramer acetate indicates that its efficacy is apparently increased as a function of usage time while the favourable side effect profile is sustained. MRI studies revealed that treatment with glatiramer acetate resulted in a significant reduction of gadolinium (Gd)-enhancing lesions. Ongoing clinical trials which might extend its usage or change its mode of delivery are also described. Glatiramer acetate appears to be a treatment of choice for the relapsing-remitting type of MS.

Immunologic therapy for secondary and primary progressive multiple sclerosis

Multiple sclerosis (MS) is generally considered an immune-mediated demyelinating disease, and treatments designed to modify the course of MS are immunosuppressive or immunomodulatory. Although most people with MS have a relapsing-remitting course initially, the majority will eventually experience a more gradual decline in neurologic function, termed secondary progressive MS. Some patients have gradual worsening from the beginning, termed primary progressive MS. Recent pathologic studies have revealed that axonal injury and neuronal degeneration are much more prominent in MS than previously recognized, and may be the explanation for the gradual decline in neurologic function that characterizes progressive MS. The results of several clinical trials in MS indicate that suppression of the immune-mediated inflammation may decrease the relapse rate in MS, but not stop the progressive loss of neurologic function. There are many promising approaches to this clinical dilemma, but none has been proven to be effective in stopping or retarding progressive MS. More well-designed, controlled, blinded, randomized clinical trials are needed to test these putative therapies. In the mean time, we should avoid subjecting patients to potentially dangerous and unproven regimens.

Treatment of multiple sclerosis: recent trials and future perspectives

In the past year, further evidence establishing the usefulness of beta interferons and glatiramer in the treatment of relapsing-remitting multiple sclerosis has been advanced. Interferon-beta-1b was also shown to be efficacious in secondary progressive multiple sclerosis. This and other trials of symptomatic treatments are reviewed. Based on an appraisal of recent experimental studies, future promising approaches to intervene in the chain of immunopathogenetic events are discussed.