WESTPORT, CT (Reuters Health) Mar 05 - Autoreactive T cells from both diabetic patients and multiple sclerosis (MS) patients target autoantigens in islet cells and the central nervous system, according to a report in the February 15th Journal of Immunology. As the authors point out, "what (usually) protects diabetics from MS, and MS patients from diabetes...could have therapeutic ramifications."
Dr. H.-Michael Dosch from The Hospital for Sick Children in Toronto, Ontario, Canada and colleagues analyzed T cell autoreactivity in 38 patients with stable or relapsing MS, 54 newly diagnosed children with diabetes and 105 of their first-degree relatives, and 34 healthy controls.
Besides recognizing myelin basic protein epitopes, T cells from MS patients frequently targeted self-antigens associated with autoimmune diabetes, the authors report, a phenomenon rarely shown by T cells from healthy controls.
Similarly, T cells from about two-thirds of diabetes patients and their first-degree relatives at high risk of developing diabetes showed proliferative responses to at least one MS-associated antigen, the report indicates. Low-risk relatives were less likely to have such autoreactive T cells.
"Thus autoimmunity in diabetes and MS targets a similar set of self-proteins, with neither disease nor tissue selectivity, although epitopes and T cell specificities appear to differ," the researchers note.
"Our work implies that there is a lengthy, clinically silent pre-MS phase analogous to prediabetes," Dr. Dosch told Reuters Health. "That's good news: there is strong consensus that we will stop diabetes within a reasonable time frame through intervention therapies that are targeted to early prediabetes. We hope (and have some reason) that the same will turn out to be true for MS, where treatments are rather ineffective."
"We are preparing for a major, multi-center initiative with several US centers to seek out evidence for pre-MS," Dr. Dosch said.
J Immunol 2001;166:2831-2841.
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