Saturday, 23 June 2012

MS Research Roundup June 2012 Part 1

Lots of interesting research to report again this time. It would be a very (very) long post if I did everything together, so I'm going to split it into two. This post will be about risk factors for MS and possible causes, and the second post (to follow shortly) will focus on treatments.

We know that more women than men have MS, and the proportion is increasing. Greek researchers compared the proportions in people living in urban and rural areas in Crete. They found that in rural areas there was less risk of MS generally, and the women:men proportion hadn't risen as it had in the towns.

This is an interesting finding. The researchers found that the urban women were more likely to smoke, drink pasteurised milk, use contraceptives, and various other factors. But so many things could possibly be involved - environmental pollution is one that springs to mind. More research needed!

Research is showing that Vitamin D is linked with a huge number of conditions, including MS. Now it seems it could also be associated with some cases where MS runs in families. British and Canadian researchers have identified a rare gene variant in these families, called CYP27B. People who inherit two copies of this gene develop a genetic form of rickets, a condition caused by vitamin D deficiency. One copy leads to lower than normal levels of vitamin D.

Out of over 3000 unaffected parents of people with MS, 35 carried the gene. In all 35 cases, the person with MS had inherited the gene. The odds against this happening by chance were enormous.

Not only does this finding go some way to explaining how MS can run in families, it also adds to the growing weight of evidence that vitamin D levels and MS are very closely linked.

We also know already that there are links between previous exposure to the Epstein-Barr virus (EBV), which causes glandular fever (mononucleosis), and the risk of developing MS. Spanish researchers discovered that naturally  lower levels of vitamin D in winter were linked with lower levels of an immune system component called TLR7. This controls the immune system response to viruses.

The researchers drew no conclusions about the impact of all this on other conditions: but could this be one piece in the puzzle of how the different MS risk factors are linked?

Several projects relating to the CCSVI theory have reported recently. First, two proof of concept studies from the USA, which examined people with MS, people with other conditions, and healthy controls using the Zamboni protocol, using ultrasound and MRV. They found that only a small proportion of people with MS had the venous constrictions said to be characteristic of CCSVI: the proportion for both people with other conditions and healthy people was similar. These studies showed no evidence that narrowed veins are linked with MS.

The European Society of neurosonology and cerebral hemodynamics examined the five criteria for diagnosing CCSVI in the Zamboni ultrasound protocol, along with the studies from which they were derived and the main studies looking at cerebrospinal drainage. Their view is that the criteria are questionable: one is based on data collected in other contexts, two have never been validated, one is technically incorrect, and two are subject to so many external influnces that it's difficult to state whether any "differences" are part of a disease or just normal variation.

As a result of these concerns, the Society strongly discourages venoplasty and/or stenting for CCSVI.

A small study in Canada followed 30 people before and after venoplasty for CCSVI. The researchers found no difference between the patients who had been treated and 10 who had not. Any initial benefits reported tailed off, particularly after about 3 months. By a year, several people's veins had reblocked, but their function was no different from those whose veins had not reblocked.

And a group of Italian reseachers carried out a meta-analysis. They critically analysed the proposed biological basis for CCSVI and reviewed all published studies on CCSVI and its ultrasound methodology. They found no supportive scientific evidence for any part of the theory that CCSVI is linked with MS. They feel that CCSVI may be a stand-alone condition, which should be investigated in its own right - but it's not linked to MS.

People have called me anti-CCSVI. That's not accurate - or wasn't. When I first heard about the idea I was interested. Who wouldn't be? I'd love a cure for my MS. But I knew really rigorous research was needed, to see if Zamboni's results could be repeated. As time has gone on, it's become increasingly apparent that the theory just doesn't hold water. If people want to have their veins Dyno-Rodded, well I suppose that's up to them. But I don't want scarce NHS funds paying for it.

On that (rather controversial) note I'll end Part 1 of this roundup. I'll try to do Part 2, dealing with treatments, tomorrow.

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