Scientists from the National Institutes of Health (NIH) have published a new study in the journal Science Translational Medicine stating a link between Nodding syndrome and an autoimmune response to the parasitic proteins of a parasitic worm. This parasitic worm has also been linked to river blindness. Nodding syndrome is a neurological disease that is common in particular areas of East Africa - Tanzania, Uganda and the Republic of South Sudan. It is a form of pediatric epilepsy where patients constantly nod their heads involuntarily, and sometimes results in terrible seizures. It has also been known to cause stunted growth in children and teenagers with some of them suffering from serious cognitive deterioration.
A link between parasitic worm causing nodding syndrome and black flies
Black flies in East Africa have been found responsible for spreading onchocerca volvulus, the parasitic worm fingered to cause river blindness and now the nodding sickness, the NIH says in a press release. Ultimately, the researchers note that nodding disease could be eliminated in East Africa if health experts would do more to eliminate both the parasitic worm and the black flies spreading it.
According to Dr. Avindra Nath, clinical director of the NIH's National Institute of Neurological Disorders and Stroke (NINDS), nodding disease may be as autoimmune in nature just as epilepsy is also autoimmune in nature, suggesting that both are diseases that respond to certain substances in the central nervous system, The Verge wrote. To this end, serum samples were taken from nodding syndrome patients and healthy people to determine the level of autoimmune response to parasitic proteins.
The researchers analyzed brain tissue and brain cells, and found leiomodin-1 within brain cells. The researchers then applied serum obtained from nodding syndrome patients and leiomodin-1 antibodies to healthy neurons cultured in a dish; they found that the neurons died off, but they later survived well when the antibodies treatment was removed. This shows that nodding syndrome is actually an autoimmune disease.
Nodding syndrome as an autoimmune disease
An autoimmune disease results when the body's immune system fights the body's own proteins and antibodies. And since antibodies tend to bind with leiomodin-1, the body's immunity attacks brain cells containing the proteins, causing the patient to start nodding his head involuntarily. But then, the researchers were able to prove that treatment therapies created for autoimmunity may help against nodding syndrome and some types of epilepsy. Although this study was supported by the NIH Intramural Program, the scientists revealed that more studies are required to substantiate the real benefits of leiomodin-1 in healthy people and in epileptic patients. This is important because some healthy people have been found to have leiomodin-1 antibodies, and scientists do not know yet if these people may eventually come down with nodding syndrome.