HTLV-I arthropathy and Sjögren syndrome.

Human T-cell lymphotropic virus type I (HTLV-I) was initially detected as the causative agent of adult T-cell leukemia (ATL). However, recent studies have revealed that HTLV-I may disrupt the immune system and lead to the development of rheumatoid arthritis and Sjögren syndrome. A current study in our laboratory has revealed that HTLV-I tax gene, known as the transregulatory gene, contributes not only to the induction of synovial cell hyperplasia but also the immune response, both in vivo and in vitro. In this report, the role of HTLV-I in the pathogenesis of chronic destructive arthropathy and Sjögren syndrome is discussed.