Thyroid hormone therapy could help reverse demyelination
Researchers at the California Academy of Science, US, have found that thyroid hormone may help the body reinsulate nerve fibres that have lost their myelin coating.
Demyelination is a central feature of multiple sclerosis pathogenesis. Myelin insulates nerve cells, and its loss triggers irreversible cell damage leading to sensory, motor and cognitive defects.
Laura Calza and colleagues in California measured a drop in the demyelination rate after administering thyroid hormone to a rat model of the disease.
The success of the treatment depended on timing, so that the hormone had to be administered during the so-called acute phase. The acute phase takes place when active damage is occurring in the nervous system.
Researchers have hypothesised that demyelination occurs as a result of defective oligodendrocyte precursor cells (OPCs), which are considered the source of the myelin layer. Thyroid appears to correct the faulty OPCs.
Calza and colleagues suggest that thyroid hormone could provide a novel, non-invasive partner to work alongside other multiple sclerosis therapies.
M Fernandez et al, Proc. Natl. Acad. Sci. USA, 2004, 101, 16363