In patients with rheumatoid arthritis, methotrexate significantly reduces abnormally elevated levels of plasmatic sRANKL, the main cytokine involved in inducing osteoporosis and bone erosions, Doina Baltaru, M.D., reported at the 4th International Congress on Autoimmunity.
Soluble RANKL (receptor activator of nuclear factor-kappa B ligand) is a member of the tumor necrosis factor cytokines and plays a major role in the regulation of bone remodeling, specifically in the stimulation of osteoclast formation, said Dr. Baltaru, of the Emergency Military Hospital in Cluj-Napoca, Romania.
Dr. Baltaru and her colleagues evaluated plasma sRANKL levels of 15 patients with rheumatoid arthritis, who had never received corticosteroids or disease-modifying antirheumatic drugs.
The study participants were assessed before and after 3 months of methotrexate therapy (15 mg/week). sRANKL levels were also evaluated in 7 healthy controls and 10 patients with type I osteoporosis.
Plasma sRANKL values were determined by quantitative enzyme-linked immunosorbent assay. At baseline, the median sRANKL value for RA patients was 467 pg/mL, though there was a wide variation (70-1,500 pg/mL). Levels ranged between 10-30 pg/mL for normal subjects and 20-200 pg/mL in patients with osteoporosis.
Methotrexate therapy significantly reduced plasma sRANKL levels in the rheumatoid arthritis patients, to a median value of 185 pg/mL.