Multiple sclerosis--in need of a critical reappraisal

The conundrum of iron in multiple sclerosis--time for an individualised approach

Although the involvement of immune mechanisms in multiple sclerosis (MS) is undisputed, some argue that there is insufficient evidence to support the hypothesis that MS is an autoimmune disease, and that the difference between immune- and autoimmune disease mechanisms has yet to be clearly delineated. Uncertainties surrounding MS disease pathogenesis and the modest efficacy of currently used disease modifying treatments (DMTs) in the prevention of disability, warrant the need to explore other possibilities. It is evident from the literature that people diagnosed with MS differ widely in symptoms and clinical outcome--some patients have a benign disease course over many years without requiring any DMTs. Attempting to include all patients into a single entity is an oversimplification and may obscure important observations with therapeutic consequences. In this review we advocate an individualised approach named Pathology Supported Genetic Testing (PSGT), in which genetic tests are combined with biochemical measurements in order to identify subgroups of patients requiring different treatments. Iron dysregulation in MS is used as an example of how this approach may benefit patients. The theory that iron deposition in the brain contributes to MS pathogenesis has caused uncertainty among patients as to whether they should avoid iron. However, the fact that a subgroup of people diagnosed with MS show clinical improvement when they are on iron supplementation emphasises the importance of individualised therapy, based on genetic and biochemical determinations.

The sad plight of multiple sclerosis research (low on fact, high on fiction): critical data to support it being a neurocristopathy

The literature for evidence of autoimmunity in multiple sclerosis (MS) is analysed critically. In contrast to the accepted theory, the human counterpart of the animal model experimental autoimmune demyelinating disease, experimental allergic encephalomyelitis (EAE), is not MS but a different demyelinating disorder, i.e. acute disseminated encephalomyelitis and acute haemorrhagic leucoencephalitis. Extrapolation of EAE research to MS has been guided largely by faith and a blind acceptance rather than sound, scientific rationale. No specific or sensitive immunological test exists that is diagnostic of MS despite the extensive application of modern technology. Immunosuppression has failed to have any consistent effect on prognosis or disease progression. The available data on MS immunotherapy are conflicting, at times contradictory and are based on findings in animals with EAE. They show predominantly a 30% effect in relapsing/remitting MS which suggests powerful placebo effect. Critical analysis of the epidemiological data shows no association with any specific autoimmune diseases, but does suggest that geographic factors and age at development posit an early onset possibly dependent on environmental influences. Certain neurological diseases are, however, found in association with MS, namely hypertrophic peripheral neuropathy, neurofibromatosis-1, cerebral glioma, glioblastoma multiforme and certain familial forms of narcolepsy. These share a common genetic influence possibly from genes on chromosome 17 affecting cell proliferation. A significant number of these disorders are of neural crest origin, the classical example being abnormalities of the Schwann cell. These and other data allow us to propose that MS is a developmental neural crest disorder, i.e. a cristopathy, implicating glial cell dysfunction with diffuse blood-brain barrier breakdown. The data on transcription factor SOX10 mutations in animals may explain these bizarre clinical associations with MS and the phenotypic variability of such alterations (Cossais et al. 2010). Research directed to the area of neural crest associations is likely to be rewarding.

B cells in multiple sclerosis

The most common laboratory abnormality in multiple sclerosis (MS) is an increased amount of cerebrospinal fluid IgG and the presence of oligoclonal bands. Despite studies of the humoral response that suggest the involvement of an infectious agent or autoantigen in disease, the major targets of the oligoclonal response are still unknown. Identification of these targets will reveal valuable insights into the cause and pathogenesis of MS and is likely to lead to effective treatment.

Infection and the etiology and pathogenesis of multiple sclerosis

Multiple sclerosis (MS) currently defies clinical and scientific definitions, and carries a prognosis that remains practically unchanged despite many years of intensive research. Although the prevailing dogma is that MS is an immune-mediated condition, it fulfills none of the criteria of an autoimmune disease. On the other hand, there is enough significant data to suggest that infectious agents(s) could be involved in either direct damage to the white matter or induce inflammatory responses that secondarily affect the brain. Our goal here is to review the data supporting the possibility that infection has a critical role in the disease, examine the list of potential candidates that have been suggested, and outline an approach regarding the potential role of infectious agents in the etiology and pathogenesis of MS.