Researchers look into how they lead to epilepsy or dementia

What happens when antibodies, a class of proteins generated by the immune system to neutralise foreign bacteria and viruses, attach themselves to the membrane protein of a human cell and try to destroy it?

Autoimmune diseases are the result. It was these auto-antibodies that were the subject of the 34th T.S. Srinivasan Endowment Oration, delivered here on Saturday by Professor Angela Vincent, Emeritus Professor of Neuro immunology at Oxford University.

“Some brain diseases caused by antibodies come on quite quickly and can become severe quickly. But they can be treated, and the patient gets better. Sometimes, the disease burns itself out and the patient can even go off treatment,” she said.

Speaking about myasthenia gravis, marked by weakness of select muscles, she said that in this disease antibodies bind themselves to acetylcholine receptors, which lead to reduced signalling between nerves and muscles. “Patients have mobility problems, sometimes they can’t keep their eyes open, in some cases they can’t swallow or drink.” But with treatment, under which the patient’s blood is removed through a centrifuge and put back minus the plasma containing the antibodies, there can be a remarkable improvement in just two days.

Sometimes, such diseases appear and disappear quite suddenly. Why does this happen though? While in some patients tumours, a preceding infection or a preceding allergic reaction is thought to have led to the disease, this may not always be the case. “It may just be bad luck if you make one of these particular antibodies,” she said.

In India, probably 10 patients per million per year could be diagnosed with diseases caused by antibodies. The earlier the disease is diagnosed and treated, the better the chances for the patient are, she said.

One interesting question researchers are now looking into is how frequently antibodies are the cause of common diseases such as epilepsy or dementia, she said.

Venu Srinivasan, chairman, TVS Motor Company, delivered the presidential address. Timothy A. Pedley, president, American Academy of Neurology; and E.S. Krishnamoorthy and Krishnamoorthy Srinivas, both of The Institute of Neurological Sciences, VHS in Chennai, spoke.