A group of local scientists says it has discovered the cause of rheumatoid arthritis.

Catholic University Professor Kim Wan-wook’s research team at Saint Vincent’s Hospital said Monday that it found the density of the bioactive protein ‘placenta growth factor,’ or PIGF, in 35 patients with rheumatoid arthritis was five times that of patients with ordinary rheumatism.

PIGF is thought to be critical to the formation of blood vessels in the placenta, but in high levels, has been linked to more severe cases of rheumatoid arthritis.

The research team said it found that the successful elimination of the PIGF protein in mice prevented the growth of antibody-induced arthritis.

The recent finding was published in the February edition of the U.S. magazine ‘Arthritis and Rheumatism.’