The Irish Times - Tuesday, August 10, 2010

CF worse for women 'due to effect of oestregen'

Dr Sanjay Chotirmall, specialist registrar in respiratory medicine at Beaumont and joint lead author of the research

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RONAN McGREEVY

IRISH RESEARCHERS claim they have identified the reason women with cystic fibrosis are affected more by the disease than men and have a lower life expectancy.

The research was carried out at the Royal College of Surgeons in Ireland (RCSI) and Beaumont Hospital and is published this month in the American Journal of Respiratory and Critical Care Medicine.

Cystic fibrosis is a life-threatening disease which primarily affects the lungs and the digestive system. A build-up of mucus can make it difficult to clear bacteria and leads to lung infections and inflammation.

The researchers found that the female hormone oestrogen prevents the release of a chemical signal (IL-8) that triggers the influx of white blood cells (neutrophils) into the lungs to fight the infection when cells are attacked by bacteria.

In the lungs, a protective layer of fluid known as the airway surface liquid (ASL) keeps the lung’s lining hydrated and defends them from infection.

In CF sufferers, this layer is thinner and previous research has demonstrated that it is reduced even further at times of elevated levels of oestrogen during the menstrual cycle, increasing the likelihood of acquiring an infection.

Ireland has the highest levels of CF in the world with a prevalence that is four times the European average due mainly to a genetic predisposition in the population to the disease.

Women with cystic fibrosis have on average a life expectancy three to five years less than men.

Joint lead author of the paper, Dr Sanjay Chotirmall, said the identification of the reason for the increased likelihood of infection means that it should now be possible to narrow the gender gap in cystic fibrosis.

He suggested that stabilising oestrogen levels or pursuing more aggressive preventative strategies against infection during the week of the four-week menstrual cycle when oestrogen levels are at their highest could radically improve treatment for female CF sufferers.

“Our ultimate aim would be improving the quality of life and survival rate for female sufferers of cystic fibrosis,” he said.