To evaluate the efficacy of cyclosporine A in the treatment of macrophage activation syndrome (MAS) occurring in children with juvenile arthritis.
MAS developed in two boys and three girls with systemic juvenile arthritis (four) and polyarticular juvenile arthritis (one). In three children whose condition was life-threatening, increased parenteral administration of corticosteroids failed to improve their condition; therefore cyclosporine A (2 to 5 mg/kg per day) was added. In two other patients with less severe clinical manifestations, cyclosporine A alone (2 to 8 mg/kg per day) was given.
After the introduction of cyclosporine A, rapid improvement was obtained in all patients and apyrexia occurred within 24 to 48 hours. The biologic abnormalities disappeared more slowly (up to 5 weeks for liver enzymes).
These observations underline the usefulness of cyclosporine A in this complication. The use of this drug may circumvent the need for increased doses of corticosteroids in some patients. The mechanism of action of cyclosporine A remains speculative, but these results indicate indirectly that T-helper lymphocytes may play a role in the pathogenesis of MAS.