Selective expression of folate receptor ? and its possible role in methotrexate transport in synovial macrophages from patients with rheumatoid arthritis

These results demonstrate that FR-beta expression is selectively elevated in RA synovial macrophages and suggest that MTX is transported through FR-beta in RA synovial macrophages. The findings suggest that folate antagonists with higher affinity for FR-beta would be useful in the treatment of RA.