Meningitis mysteries unravel

09 August 2010

Research supported by Meningitis Research Foundation has begun to reveal the answers to two of the most fundamental questions about meningitis and septicaemia.

The main cause of meningitis and septicaemia in the UK and Ireland is meningococcal bacteria which live in the back of the noses and throats of around 10 per cent of the population. Why is it that a relatively small proportion of people go on to develop meningococcal disease and why do some people develop more severe disease than others?

Part of the answer, suggests the research published in Nature Genetics, lies in our genes.

The international study, led by Professor Michael Levin at the Department of Paediatrics at Imperial College London, is the largest genetic study of meningococcal meningitis and septicaemia yet undertaken, and is the culmination of 15 years of detective work.

The international teams utilised new approaches enabling rapid scanning of the whole human genome. Searching the entire human genome for factors which influence susceptibility to meningococcal inflection, the study found key genetic variations in related proteins which prevented the body’s defence systems from attacking and killing the invading bacteria. The study provides definitive evidence that genetic factors are important in determining susceptibility to meningococcal disease.

The results from UK patients were reproduced in patients from Holland, Austria and Spain, confirming the importance of genetic variation in proteins in meningococcal susceptibility. Many UK patients who took part were MRF members with first-hand experience of this deadly disease and intent on fighting it.

The study has shown that genetic variation in a group of proteins, called Factor H and Factor-H related proteins, are particularly important in determining susceptibility and resistance to meningococcal infection.

These proteins are part of the complement system normally present in the blood of all individuals. Complement is part of the body’s defence against infection and once activated binds to, and kills, invading bacteria. The meningococcus is known to carry a surface protein which binds human Factor H which in turn prevents killing of the bacteria by the complement proteins. This appears to be a ‘Trojan horse’ mechanism where the bacteria evade killing by the human immune system by covering itself with the Factor H protein.

The definitive identification in this study of Factor H and Factor H-related proteins as major determinants of meningococcal disease susceptibility will be crucial both for understanding the disease and may have implications for developing effective vaccines.

Professor Levin said, “The study highlights the power of the new genomic technologies which are now helping to unravel the basis of human disease. This is an important breakthrough in our understanding of this infection and will be important in the development of effective vaccines.”

Linda Glennie, Head of Research and Medical Information at MRF commented, “We are delighted that our investment in this research has helped uncover some of the reasons why some people are more susceptible to meningitis and septicaemia and why the diseases affect some people more than others. We hope that our continued investment in Professor Levin’s research will result in improved future treatment and, ultimately, contribute to the prevention of meningitis and septicaemia through vaccination.”

Read MRF Research Officer Gill Currie's blog piece

For further information please contact Leah Whiting on 01454 280416 or email: leahw@meninigitis.org.
Out of office hours - 07711 057875


NOTES TO THE EDITOR:

• Meningitis Research Foundation has committed over £500,000 to this programme of genetic research since 1999.
• Meningitis Research Foundation is currently funding 26 research projects into the prevention, detection and treatment of meningitis and septicaemia. The Foundation has spent £16 million on research since its inception in 1989
• Meningitis Research Foundation operates a freefone 24 hour helpline – 080 8800 3344 – providing information on meningitis and septicaemia to the general public and health professionals
• The Foundation offers support for those affected by meningitis and septicaemia. Trained helpline staff are available 365 days a year. A befriender service links people with experience of meningitis and septicaemia to share their experiences and counsel each other