RS3PE syndrome: Autoinflammatory features of a rare disorder

ABSTRACT Remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome was first described by McCarty in 1985 and is characterized by pitting oedema and an acute symmetrical synovitis of small joints. Self-directed inflammation in autoimmune disorders is caused by an abnormal activation of the adaptive immune system, while in autoinflammatory disorders, it is due to aberrant activation of the innate immune system without autoantibodies or autoreactive T cells. The role of autoimmunity in the pathogenesis of RS3PE syndrome is suggested by possible associations with some autoimmune diseases and human leukocyte antigen (HLA) haplotypes. However, several other features point to a possible role of autoinflammation in RS3PE syndrome. In this review, the relative contributions of both innate and adaptive immune systems to the pathogenesis of RS3PE syndrome are discussed.