Role of basophils in rheumatoid arthritis

The T helper (Th)1/Th2 imbalance plays a crucial role in the development of rheumatoid arthritis (RA). It is well known that basophils can affect the Th1/Th2 balance by enhancing the Th2 response, while impairing the Th1 response, which is known to be involved in the development of a number of diseases. However, limited information is available with regard to the role of basophils in RA. Decreased levels of circulating basophils and a dominant Th1 response have been reported in adult patients with RA, while children with juvenile RA have been largely found to have increased levels of circulating basophils and a dominant Th2 response. Furthermore, the circulating basophils in the two conditions have an activated phenotype and are associated with disease activity. In addition, a longitudinal study found the Th2 response was dominant in the early stages of RA, while the Th1 response was dominant in long-term chronic RA. These observations indicate that basophils may be involved in the development of RA by affecting the Th1/Th2 balance, particularly in the early stages of RA. Therefore, targeting basophils may be a novel therapeutic strategy for the treatment of RA; however, further investigation is required.