Smoking affects responses to anti-TNF therapy in Rheumatoid Arthritis patients, according to a study published in the Journal of Rheumatology.

Anti-TNF is a class of drugs designed and pioneered by the Arthritis Research Campaign for the treatment of rheumatoid arthritis and other inflammatory diseases.

The drugs work by reducing levels of a protein called TNF, excessive amounts of which cause inflammation when they build up in the bloodstream or joints.

They are only prescribed to patients who have not responded to other treatment such as methotrexate.

In the new study, researchers from the University Hospital of North Staffordshire have suggested that smoking history reduces the effectiveness of anti-TNF therapy.

The researchers questioned 154 patients who started anti-TNF treatment in 2002 about whether they had ever smoked and then calculated average pack-years (one pack year is equal to 20 cigarettes smoked daily for one year).

It was discovered that there was an increasing trend of no response to the treatment at three months and at 12 months related to higher pack-years.

"Rheumatoid arthritis patients with a history of smoking were more likely to show a poor response to TNF antagonists," the researchers concluded.

"Response failure was associated with the intensity of previous smoking, irrespective of smoking status at initiation of anti-TNF therapy."

A form of inflammatory arthritis, rheumatoid arthritis affects around 350,000 people in the UK. The disease is more common in women and men and generally develops between the ages of 30 and 50.

A spokesman for the Arthritis Research Campaign said that smoking was already known to be risk factor for developing rheumatoid arthritis.

"This new research adds to an existing body of evidence that smoking is a really bad idea for people at risk of or with rheumatoid arthritis," he added.


source : http://www.arc.org.uk/news/article/19174227