The joint inflammation that is a hallmark of rheumatoid arthritis apparently results from out-of-kilter hormone levels in the joints, European researchers report.
They found that in patients with rheumatoid arthritis (RA), joint fluid levels of estrogens, which tend to promote inflammation, are elevated relative to androgens, which damp down inflammation.
Determining the ratio of estrogens to androgens in joint fluid “may be a helpful diagnostic tool for the assessment of the local inflammatory situation,” say the researchers.
“The observed shift in the direction of estrogens in relation to androgens is a supporter of the inflammatory process in arthritis,” lead author Dr. Rainer H. Straub from University Medical Center in Regensburg, Germany, told Reuters Health.
In the study, the overall concentration of free estrogens in joint fluid tended to be higher in 12 people with RA than in 8 patients with traumatic knee injury, who served as a comparison control group. The ratio of free estrogens to free androgens was also elevated in RA subjects compared to control subjects, the investigators report in the December issue of The Journal of Rheumatology.
The team also found, in lab experiments, that the sex-hormone precursor dehydroepiandrosterone (DHEA) is rapidly converted to estrogens in cells that line the joints.
The evidence from this study “may provide a basis to develop an alternative hormonal therapy for RA patients, using strategies designed to achieve a reduction in estrogen formation,” the researchers conclude.
– Journal of Rheumatology, December 2003.