RSЗPE Syndrome: Autoinflammatory Features of a Rare Disorder

Remitting seronegative symmetrical synovitis with pitting edema (RSЗPE) syndrome was first described by McCarty in 1985 and is characterized by pitting edema 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 is due to aberrant activation of the innate immune system without autoantibodies or autoreactive T cells. The role of autoimmunity in the pathogenesis of RSЗPE syndrome is suggested by possible associations with some autoimmune diseases and HLA haplotypes. However, several other features point to a possible role of autoinflammation in RSЗPE syndrome. In this review, the relative contributions of both innate and adaptive immune systems to the pathogenesis of RSЗPE syndrome are discussed.