Paint, varnish can increase risk of multiple sclerosis

Genes have long been implicated in MS; paint or varnish may increase that risk

In people with a certain genetic makeup, exposure to paint, varnish and other solvents could make them more susceptible to developing multiple sclerosis (MS). According to a study published in Neurology®, the medical journal of the American Academy of Neurology, people with exposure to paint or other solvents are 50 percent more likely to develop MS.

MS is a chronic immune-mediated disease where the myelin sheaths covering the nerve cells of brain and spinal cord gets damaged resulting in symptoms that include numbness, blurred vision, impairment of speech and of muscular coordination and severe fatigue. Myelin sheaths play an important role in the transmission of impulse from one nerve cell to the next. Globally, there are about 2.3 million cases of MS while India is home to about two lakh cases. There is no definitive cure for MS till date.

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 genetic risk factors

People with exposure to solvents who also carry the genes that make them more susceptible to MS 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 have been 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 genetic risk factors.

“These are significant interactions where the factors have a much greater effect in combination than they do on their own,” said study author Anna Hedström, MD, PhD, of the Karolinska Institutet in Stockholm, Sweden. “More research is needed to understand how these factors interact to create this risk. It’s possible that exposure to solvents and smoking may both involve lung inflammation and irritation that leads to an immune reaction in the lungs.”

Researchers identified 2,042 people who had recently been diagnosed with MS in Sweden and matched them with 2,947 people of the same age and sex. Blood tests were carried out to determine whether the participants had two human leukocyte antigen gene (HLA  gene) variants, one of which makes people more likely to develop MS and the other reduces the risk of MS.

The participants were also asked whether they had been exposed to organic solvents, painting products or varnish and 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.