In vitro effect of biological and conventional disease-modifying antirheumatic drugs on fibrocyte differentiation in patients with rheumatoid arthritis and healthy controls

Fibrocytes are circulating bone-marrow-derived cells that migrate to organs with ongoing repair or inflammation. In the target organ, the cells differentiate, become long and spindle-shaped, and are able to produce extracellular matrix components. In fibrotic diseases, the levels of fibrocytes are increased, both in circulation and the diseased tissue. In rheumatoid arthritis (RA), fibrocytes have been proposed to be involved in the spread of the disease and possibly in RA fibrotic manifestations, as can be seen in RA interstitial lung disease (RA-ILD). Therefore, we aimed to investigate a range of current RA treatment modalities (corticosteroids and conventional and biological disease-modifying antirheumatic drugs (DMARDs)) regarding their effect on in vitro fibrocyte differentiation.