Exploring perinatal mesenchymal stromal cells as a potential therapeutic strategy for rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease characterized by inflammation in the synovial tissue, driven by aberrant activation of both the innate and adaptive immune systems, which can lead to irreversible disability. Despite the increasing therapeutic approaches for RA, only a low percentage of patients achieve sustained disease remission, and the persistence of immune dysregulation is likely responsible for disease recurrence once remission is attained. Cell therapy is an attractive, wide-spectrum strategy to modulate inflammation, and mesenchymal stromal cells (MSC) derived from perinatal tissues provide valuable tools for their use in regenerative medicine, mainly due to their immunomodulatory properties. Several in vitro studies have shown that perinatal MSC modulate the proliferation, maturation, and cytokine secretion profile of both innate and adaptive immune cells. Moreover, different beneficial effects have also been described when perinatal MSC were used to treat animal models of diseases associated with inflammatory conditions and degenerative processes. Specifically, in experimental models of RA, treatment with perinatal MSC resulted in a strong reduction of articular damage, which was associated with the modulation of both inflammation and activation of stromal resident cells in the synovial tissue. Here, we present in vitro and in vivo evidence supporting the use of perinatal MSC in RA. We also highlight the promising results from the few published clinical trials, which demonstrate the safety of perinatal MSC.