Multiple Sclerosis (MS) is a condition that impacts on the central nervous system, affecting more than 25,000 Australians. The symptoms range from problems with motor control, incontinence, fatigue and other neurological and neuropsychological symptoms.
There is no known cure for MS so far and researchers have been investigating the possible causes and cures for multiple sclerosis. In fact, researchers from Karolinska Institutet in Stockholm, Sweden, hypothesised that different sources of lung irritation may contribute to an immune reaction in the lungs and can subsequently lead to multiple sclerosis (MS) in people with a genetic susceptibility to the disease.
They investigated the influence of an exposure to organic solvents on MS risks, as well as a potential interaction between organic solvents and MS-risk human leukocyte antigen (HLA) genes.
The researchers used a Swedish-population based control study and identified 2042 people who had recently been diagnosed with MS and matched them with 2947 people of the same age and sex. Blood tests were taken to determine whether the participants had two human leukocyte antigen gene variants — one of which increases the risk of developing MS and the other reduces the risk of MS. The participants were then asked whether they had been exposed to organic solvents, painting products or varnish. They were also asked whether they had ever been a smoker.
In the group with neither of the MS genes and no smoking or exposure to solvents, there were 139 people with MS and 525 people without the disease. In the group with the MS genes and exposure to solvents but no smoking, there were 34 people with MS and 19 people without the disease. In the group with MS genes and exposure to solvents and smoking, there were 40 people with MS and five people without the disease.
The findings show that people with exposure to paint or other solvents are 50 per cent more likely to develop MS than people with no exposure. People with exposure to solvents and who also carry the genes for MS risk are nearly seven times as likely to develop the disease as people with no solvent exposure who do not carry the MS genes.
The risk is even greater for people who are smokers. Those who have been smokers with solvent exposure and the MS genes are 30 times more likely to develop MS than those who have never smoked or been exposed to solvents and who do not have the MS genes. The researchers found that MS genes and exposure to solvents combined were responsible for an estimated 60 per cent of the risk of developing MS.
It’s not known how the combination of organic solvents, smoking and MS genes contributes so significantly to the risk of MS. It may be possible that exposure to solvents and smoking may cause lung inflammation and irritation which can lead to an immune reaction in the lungs, according to the researchers. The researchers advocate that people with a family history of MS should make lifestyle changes as well as avoid smoking and unnecessary exposure to organic solvents to reduce the risk of developing MS.
Source: Neurology
