More than two million people worldwide have multiple sclerosis (MS). In a worrying trend, the number of new patients appears to be increasing – especially the number of women, compared with men, developing this chronic incurable disease of the central nervous system.

This week more than 7000 leading MS physicians and researchers are in Lyon, France, attending the annual scientific conference of The European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS).

In the official Conference press briefing, leading MS clinicians described some of the unanswered questions currently perplexing the MS community.

“One concern is the growing proportion of women, compared with men who develop MS. Since the 1950s this proportion has grown from a ratio of 2:1 (women to men) to 3:1. “We don’t know why,” said Professor Christian Confavreux, Hopital Neurologique, Lyon, France and Chair of ECTRIMS 2012.

When asked about the apparent increase in MS currently occurring in the Middle East, the panel said that this was a mystery, but there were clues.

“MS seems to be a disease of ‘modern life’ “, said Professor Confavreux. As less developed societies modernise, many factors change, such as basic hygiene, vaccinations, smoking, and diet.

“We don’t know what it is, but something about this new way of life is leading to an increase in MS.” He pointed to the French West Indies where a major study had yielded intriguing findings.

People from islands such as Martinique and Guadeloupe who emigrated to France in the 1950s and subsequently moved back to their place of birth, showed a five-fold higher rate of MS than people born at around the same time who never left the islands. The theory that this had something to do with improved hygiene in the host country [France] was ‘very seductive’, he said – the notional idea being that when hygiene improves, the body’s immune system becomes less challenged and this somehow can help trigger MS following viral or other infection.

Several ECTRIMs presentations cover the potential role of viruses in triggering MS. “It is conceivable that a microbe, while harmless in one individual, may contribute to trigger MS in another,” says Professor Renaud Du Pasquier, CHUV, Lausanne. He cites the Epstein-Barr virus which causes infectious mononucleosis and which increases the risk of developing MS risk three-fold in infected individuals.

Professor Confavreux said that the MS community now has plenty of treatments for helping prevent relapses in MS patients, however the remaining challenge is to find treatments that prevent progression of disease (accumulation of handicap).

When asked why an abundance of new drugs are now being developed or coming on stream, Professor Michel Clanet, Le Centre Hospitalier Universitaire de Toulouse (CHU) France, and President of ECTRIMS pointed to new understanding of the autoimmune basis of MS and a raft of new research by colleagues in immunology, whom he characterised as “very clever”.

“They understand the immune system, the cascade of inflammatory mediators such as cytokines and they know how to modify this cascade so there are more new drugs being developed,” he said.

Professor Confavreux sounded a note of caution when tinkering with the immune system – especially when patients might need treatment for three or four decades. He felt this needed careful risk assessment. “We need to know true risks of performing immune therapy”, he said.

Professor Confavreux highlighted the importance of determining long term efficacy in everyday clinical use, rather than in the somewhat artificial setting of clinical trials. Professor Clanet agreed. “We need to see what happens in large populations, because patients in clinical trials are very selected. It is very important to follow patients in Phase IV [long term] observational studies,” he said.

Fortunately, such data are now emerging for newer immunomodulating treatments. A symposium Tuesday evening, summarised global ‘real world’ experience with the first oral once-daily immunomodulating MS treatment Gilenya (fingolimod).

Since the drugs launch two years ago it has been given to approximately 49,000 patients in 65 countries accumulating some 52,000 patient-years of exposure, said Professor Jean Pelletier, head of the department of Neurology at Timone University Hospital, Marseille, France.

Dr Martin Duddy, Consultant Neurologist at the Royal Victoria Infirmary, Newcastle-upon-Tyne, UK said that an increasing evidence base supported the drugs use in MS, with cumulative data showing rapid and sustained disease control plus a well characterised safety profile.

Written by Ian Mason PhD