One size does not fit all( Statins a commonly prescribed class ...)

Statins, a commonly prescribed class of drugs used by millions worldwide to effectively lower blood cholesterol levels, may actually have a negative impact in Multiple Sclerosis (MS) patients treated with high daily dosages.

A new study by researchers at the Montreal Neurological Institute (MNI), McGill University, demonstrates that statin therapy in mice inhibits myelin repair or remyelination in the central nervous system. The findings, published in The American Journal of Pathology, highlight the crucial need to monitor the effects of central nervous system-accessible immune therapies on the myelin repair processes in patients with MS and other progressive demyelinating diseases.

Canadians have one of the highest rates of MS in the world. An estimated 50, 000 Canadians have MS, with approximately 1,000 new cases diagnosed each year. MS is an autoimmune disease of the central nervous system (CNS), in which immune cells attack the myelin sheath (the protective insulation of nerve fibres), and the myelin-producing cells of the CNS (oligodendrocytes), causing demyelination. This causes damage which disrupts the nerve cell's ability to transmit signals throughout the nervous system.

In the early stages of MS, following an immune system attack on myelin, oligodendrocyte progenitor cells or stem cells in the CNS are recruited to the lesion. These cells mature and produce new myelin to repair the damage.

"Statins, which are known to modify the immune system response and have a wide array of effects on other cellular processes, were propelled into clinical trials based on studies in an animal model of MS indicating a reduction in clinical disease severity," says Dr. Veronique Miron, post-doctoral fellow in Dr. Jack Antel's lab at the MNI, and lead investigator in the study. "The mechanism of statin action in these studies was not determined. That is, does statin directly effect myelin and/or the oligodendrocytes or is dise
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