Cholesterol-lowering statin drugs used to combat heart disease may also help people with rheumatoid arthritis, research suggests.
Arthritis can be very painful
Rheumatoid arthritis is linked to over-production of the synovial tissue which lines the joints.
In lab tests, scientists found statins could induce the cells that produce this tissue to kill themselves.
The study, led by Japan's Jichi Medical School, features in the journal Arthritis & Rheumatism.
Statins have already been shown to induce cell death - or apoptosis - in both normal cells and tumour cells.
The Japanese team found a particular type of statin, fluvastatin, could produce the same effect on synovial cells taken from people with rheumatoid arthritis.
However, the drug had no effect on cells taken from people with another form of arthritis called oestoarthropathy.
The concentrations of statins used in the experiment were much higher than those that would normally be prescribed to patients.
The researchers said it was possible that lower concentrations of the drugs may have a similar effect on patients, but accept that more work is needed.
Dr Madeleine Devey, medical adviser to the Arthritis Research Campaign, said: "There have been several studies on the potential anti-inflammatory effects of statins in rheumatoid arthritis.
"This interesting paper suggests a possible mechanism for these effects supporting their potential benefit in treatment."
Ailsa Bosworth, of the National Rheumatoid Arthritis Society, said much good work was currently being done to try to minimise the inflammation associated with rheumatoid arthritis, including the introduction of anti-TNF drugs.
"The potential use of statins to reduce inflammation is a very interesting and exciting concept."
The role of statins in treating people with rheumatoid arthritis is to be studied further in a major trial funded by the Arthritis Research Campaign and the British Heart Foundation.
More than 3,500 patients with rheumatoid arthritis are to take part in the study, which is designed to find out if statins will cut the numbers dying from heart attacks and strokes.
People with rheumatoid arthritis face an increased risk of dying from cardiovascular complications compared with the general population.
But despite this, few are routinely prescribed statins.
Doctors taking part in the trial say that if, as expected, statins were shown to reduce cardiovascular deaths in rheumatoid arthritis patients, then most patients with the condition should be routinely put on the drugs.
Jane Tadman, a spokeswoman for the Arthritis Research Campaign, said: "If it could be proved that statins can both reduce inflammation and cardiovascular risk in rheumatoid arthritis patients, then there would be quite a strong case for most patients being prescribed the drugs sooner, rather than later."