Johns Hopkins Researchers Discover Key Protein Linked To Transverse Myelitis And Multiple Sclerosis

From Johns Hopkins Medical Institutions

Hopkins researchers have discovered a single molecule that is a cause of an autoimmune disease in the central nervous system, called transverse myelitis (TM), that is related to multiple sclerosis.

In a study published in the October issue of The Journal of Clinical Investigation, it was showed that the levels of the protein, IL-6, are dramatically elevated in the spinal fluid of transverse myelitis (TM) patients.

Although the majority of TM patients suffer a single attack, 15 percent to 30 percent of patients go on to develop full-blown MS.

IL-6 is a chemical messenger that cells of the immune system use to communicate with one another. One of the cell types injured by high levels of IL-6 includes oligodendrocytes, which help produce the protective myelin sheath coating around nerve cells. The findings offer one possible mechanism responsible for demyelinating disorders, such as TM and MS, and may aid in the development of effective therapies against these disorders, the researchers say.

"This is the first time a single culprit has been identified as causing a CNS autoimmune disease," said Kaplin.

Researchers analyzed 42 inflammatory proteins in the cerebrospinal fluid of both TM and healthy patients. They found that IL-6 was consistently elevated in TM patients' spinal fluid. Further, the level of IL-6 directly correlated with the severity of paralysis.

Using cell culture and animal studies, the researchers confirmed that elevated IL-6 levels were directly injurious to the spinal cord. They showed that spinal fluid from TM patients induced death of spinal cord cells when cultured in a dish and that IL-6, when infused in adult rats, induced paralysis. Under the microscope, tissue from IL-6-infused rats showed demyelination and injury of axons, pathology that was nearly identical to that seen in human patients with TM.