Antibodies to infections can cause neurological disorders
Nodding syndrome is an epileptic seizure disorder that affects children in isolated parts of Africa. Its cause remains unknown, and there is no effective treatment, despite extensive investigations by multiple international agencies. As a result, the illness devastates the regions where it occurs.
IRP researchers led by Avindra Nath, M.D., took a novel approach by searching the blood and spinal fluid of nodding syndrome patients for autoantibodies, a sign of an autoimmune reaction in which a patient’s immune system attacks his or her own bodily tissues. The investigators found that the patients had autoantibodies to a protein in the brain called LMOD-1, which is present in neurons but had not been previously studied in the brain. Moreover, the autoantibodies cross-reacted with a protein present in cells of the parasite Onchocerca volvulus, a nematode that causes river blindness in the same regions of Africa where nodding syndrome occurs, suggesting the possibility that nodding syndrome may be triggered by an autoimmune response resulting from prior infection with the parasite.
The team’s findings suggest that eradicating the Onchocerca volvulus parasite should prevent new cases of nodding syndrome and may have similar implications for other regions of the world where such parasitic infections exist. It also opens up new lines of research to understand the role of LMOD-1 in brain development and neuronal function.
Johnson TP, Tyagi R, Lee PR, Lee MH, Johnson KR, Kowalak J, Elkahloun A, Medynets M, Hategan A, Kubofcik J, Sejvar J, Ratto J, Bunga S, Makumbi I, Aceng JR, Nutman TB, Dowell SF, Nath A. (2017). Nodding syndrome may be an autoimmune reaction to the parasitic worm Onchocerca volvulus. Sci Transl Med. Feb 15;9(377).