A group of researchers with Danish participation have discovered what causes some autoimmune diseases such as rheumatoid arthritis and lupus to evolve and grow worse. The answer may be the key to curbing other incurable autoimmune diseases where the body begins to attack itself.

2017.09.05 | Mette Louise Ohana

Approximately 300,000 Danes suffer from an incurable autoimmune illness such as rheumatoid arthritis.

No one knows exactly why the immune system occasionally begins to attack healthy organs and tissue, triggering chronic autoimmune diseases such as multiple sclerosis, rheumatoid arthritis and metabolic disorders. But a new study now provides an answer to how certain autoimmune diseases spread in the body. This in turn paves the way for the development of more targeted medicine, which can potentially prevent diseases such as rheumatoid arthritis and the somewhat rarer lupus from developing.

This is the hope brought forth by the new research result, which has just been published in the scientific journal Cell. A researcher from Aarhus University is one of the people behind the discovery, in collaboration with colleagues from Harvard Medical School and Boston Children's Hospital. 

Important knowledge for developing medicine 

When a person suffers an infection, the immune system normally forms antibodies that neutralise the disease by binding to components of bacteria and viruses, known as antigens. The same process takes place with some autoimmune diseases, albeit with the crucial difference that the immune system produces antibodies to fight components of the body's own cells and tissues, known as autoantigens.

Medical doctors and researchers have long known that the disease develops over time, so that more organs and tissues come under attack. In lupus patients this is seen as for example joint pain, kidney damage and rashes. But no one has understood how this process evolves.

"We have discovered that the B cells which produce the antibodies over time recruit other B cells to develop harmful antibodies. The disease thus spreads like ripples in water. The fact that we can now show precisely what happens at a cellular level for some of these diseases is a big step in the right direction when it comes to developing targeted medicine that can curb the negative spiral which the immune system initiates," explains Søren Egedal Degn, who is assistant professor at the Department of Biomedicine at Aarhus University and the initiator behind the research project. 

He emphasises that autoimmune diseases are a highly complex field, and that the new knowledge only applies to some of the diseases. On the other hand, it can be implemented in current medical treatment for rheumatoid arthritis and lupus, making it possible to treat patients at an early stage. However, it will take around five years before any new medicine is ready for use, as it must first be developed and tested.

About autoimmune diseases

• Autoimmune diseases cover quite frequent diseases such as type 1 diabetes, psoriasis, a subset of metabolic disorders, and rheumatoid arthritis to rarer conditions such as Systemic Lupus Erythematosus (SLE) and Sjogren's syndrome.
• A total of approx. 300,000 Danes suffer from an autoimmune disease.
• In the western world, autoimmune diseases are among the most frequent causes of death and impaired quality of life, and incidences of autoimmune diseases are increasing rapidly.
• Women account for three out of four cases of autoimmune diseases.          

Sources: The Danish patient association De autoimmune (in Danish only), the Autoimmune Registry and the American Autoimmune Related Diseases Association.

The research results – more information

• The study is basic research.
• The research results are a result of collaboration between researchers from Aarhus University and Harvard Medical School, Boston Children's Hospital, Stanford University and Massachusetts Institute of Technology, among others.
• The study is financed by the EU via Søren Egedal Degn’s Marie Curie Fellowship, with additional support from the Benzon Foundation and the National Institutes of Health.
• The scientific article ”Clonal Evolution of Autoreactive Germinal Centers” is published in the scientific journal Cell.

Contact

Assistant Professor Søren Egedal Degn
Aarhus University, Department of Biomedicine
Mobile: (+45) 2214 1703
Email: sdegn@biomed.au.dk