Finding offers hope to Sjogren's sufferers; autoimmune disease affects moisture glands

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Finding offers hope to Sjogren's sufferers; autoimmune disease affects

moisture glands

 

HELEN BRANSWELL

Canadian Press

Monday, October 07, 2002

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TORONTO (CP) - A surprise finding by researchers investigating a suspected

link between Type 1 diabetes and multiple sclerosis may help people with a

highly irritating condition known as Sjogren's syndrome.

The team of scientists from the Hospital for Sick Children has discovered a

protein that is critical for the development of Sjogren's, an autoimmune

disease that attacks the body's moisture-producing glands. " We were looking

for gold and we struck oil, " explained senior investigator Dr. Dosch

of the work, which is published in the current issue of the medical journal

The Lancet.

Dosch and his team are hopeful that the process which triggers Sjogren's can

be turned off - and the damage done by the disease essentially reversed - by

vaccinating people who suffer from it. They even have a prototype vaccine

they hope can be put into human trials in a year or so.

The process works in mice, but more research is needed on the human form

before clinical trials can be undertaken.

" It even worked late in the disease and stopped it and even made it go

almost normal, " Dosch said in an interview. " It comes out of left field. I

mean, nobody would have ever guessed. "

The team is working with Dr. Arthur Bookman, a rheumatologist who runs a

Sjogren's clinic at Toronto Western Hospital, to recruit people suffering

from the disease. (Bookman is also a co-author of the study.)

They need to do further study of the role of the protein, ICA69, in the

human disease to determine whether the reaction to it is the same across the

board. They plan to do that by testing blood samples from between 70 to 100

Sjogren's patients.

If it is, the team will seek approval for trials testing the vaccine on

humans.

Theresa Spence, who has suffered from Sjogren's syndrome for more than 25

years, is thrilled at the news.

" Isn't that exciting? And that it could be reversed? It's amazing, " says

Spence, a Toronto woman in her 50s.

The disease's trigger is not known, though some suspect it is a virus.

Whatever the cause, it prompts the body's immune system to go haywire.

Instead of attacking foreign invaders like bacteria and viruses, it attacks

ICA69, which is found in moisture-producing glands like tear ducts and

salivary and sweat glands.

The result: the glands stop working. Excruciatingly dry eyes and dry mouth

are only the beginning of the problems.

Spence must use artificial tears to keep her eyes moist. She can't swallow

most foods without the help of a drink. (Bookman said a good way to diagnose

Sjogren's is to ask a suspected sufferer to chew and swallow a soda cracker.

" They never can. " )

Spence doesn't sweat, so she has to avoid activities in which she'll become

overheated. " Once I've heated up, I stay like a solid little brick for ages.

It's just awful. "

The problems might seem minor. They are anything but.

" I've had tonnes and tonnes of cavities. Extensive dental work to try and

save teeth, " Spence explained.

" They considered implants because I've lost teeth at the back, but because

I've been on steroids so often I have bone loss so (that's not an option).

And false teeth are not a good thing for me, because I would just have

irritation " because of the lack of moisture.

Sjogren's often progresses to attack internal organs and the body's blood

vessels. Spence has suffered a lung embolism, has had to have her spleen

removed, and has endured several bouts of bacterial pneumonia which were

exacerbated by the fact she has no spleen.

Spence and all Sjogren's patients walk around knowing one in 10 of them will

go on to develop something far more serious.

" The biggest worry of mortality in these patients is lymphoma, " Bookman

said. " The immune system gets so revved up it takes off on its own and

becomes malignant. "

It's estimated that one in 100 people - the vast majority of them women -

suffer from Sjogren's syndrome. Many of them develop it as a side-effect of

other autoimmune diseases, such as lupus and rheumatoid arthritis, Bookman

said.

Despite that, the disease has no public profile and many doctors are not

familiar with it.

" The average patient has to see three doctors and it takes up to three years

before they can find a diagnosis, " Bookman said.

" It's an orphan disease in a way, " Dosch agreed.

" It doesn't kill. It's a real nuisance. Some people even go blind. But

there's no understanding of the disease. It's hard to diagnose and there's

no therapy. "

This accidental discovery that ICA69 is the target of the autoimmune attack

may lead to one. The idea would be to desensitize the immune system to the

protein, essentially teaching the body that ICA69 poses no threat.

Dosch is hopeful that as part of the bargain, science will learn a lot more

about shutting down other debilitating autoimmune processes. Researchers

have been working on developing vaccines for some of these diseases, but

have never managed to translate success in animal trials into success in

humans.

Sjogren's should be an easier task, he said, because it appears that only

one protein is targeted by the autoimmune response. In diseases like lupus

and rheumatoid arthritis, multiple proteins are involved.

" This may be the door to allow us to learn how to translate animal data into

humans, " Dosch said. " And it may be as simple as finding the right dose. "

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