Researchers are working on an innovative approach to treat a rare autoimmune disease of the peripheral nervous system, using a kind of molecular sponge made of sugar to remove pathogenic antibodies from the bloodstream. Developed to treat anti-MAG neuropathy, the approach also has potential applications in the treatment of other autoimmune diseases. Scientists from the University of Basel and University Hospital Basel have reported their findings in the scientific journal PNAS.
Patients with anti-MAG neuropathy suffer from, among other things, loss of sensitivity in the arms and legs, neuropathic pain, and a loss of coordination that can impair mobility. Through progressive damage to the peripheral nerves, the patients become increasingly restricted in their day-to-day lives until they require full-time care.
The disease can be identified in the blood serum with autoantibodies that bind to the myelin-associated glycoprotein (MAG) in the peripheral nervous system. These anti-MAG antibodies have long been seen as the cause of the disease. It is also known that a reduction in the antibody concentration in the blood leads to an improvement in the symptoms.
To date, an approved treatment that specifically targets these autoantibodies has not been available. Current treatments seek only to suppress the immune response; they are inefficient and in some cases cause serious side effects.
Artificial molecule as a sponge
Basel-based researchers are thus working on a new treatment method with customized synthetic glycopolymers that work like a sponge on the harmful autoantibodies. The glycopolymer simulates the section of the MAG protein to which the anti-MAG antibodies bind.
The scientists showed in vitro that the glycopolymer neutralizes the antibodies in the patient’s serum that cause the disease. The anti-MAG antibodies in immunized mice were also removed effectively.
Potential for other autoimmune diseases
This new treatment method offers significant potential not only for antigen-specific treatment of anti-MAG neuropathy, but also for other antibody-mediated autoimmune diseases.
As we have no, or only fragmentary, knowledge of the antigens in many autoimmune diseases, antigen-specific treatment methods are generally very difficult to develop. “The use of glycopolymers opens up new possibilities in the treatment of diseases in which anti-glycan antibodies play a role,” says study director Professor Beat Ernst from the Department of Pharmaceutical Sciences at the University of Basel. Examples of such diseases include multifocal motor neuropathy or Guillain-Barré syndrome.
Collaboration with spin-off
The findings arose from a joint project between the University of Basel’s Department of Pharmaceutical Sciences and Polyneuron Pharmaceuticals AG, a University of Basel spin-off founded by Dr. Ruben Herrendorff, Professor Andreas Steck and Professor Beat Ernst in 2014. The project was funded by the Commission for Technology and Innovation (CTI), the Gebert Rüf Foundation, and the Neuromuscular Research Association Basel.
Polyneuron Pharmaceuticals AG is currently preparing for the clinical trial of the glycopolymer drug for the treatment of anti-MAG neuropathy.