Precordial pain, leukocytosis and bicytopenia in a teenager with systemic juvenile idiopathic arthritis under immunosuppressive therapy

Abstract

Objective: To highlight the importance of the new classification criteria for the macrophage activation syndrome (MAS) in systemic juvenile idiopathic arthritis in order to reduce morbidity and mortality outcome related to this disease. Case description: A 12-year-old female patient with diagnosis of systemic juvenile idiopathic arthritis under immunosuppression therapy for two years developed cough, acute precordial chest pain, tachypnea,tachycardiaandhypoxemiafortwodays.Chesttomography showedbilaterallaminarpleuraleffusionwithbibasilarconsolidation. Theelectrocardiogramwasconsistentwithacutepericarditisandthe echocardiogramshowednoabnormalities.Laboratoryexamsrevealed anemia, leukocytosis and increased erythrocyte sedimentation rate, as well as C-reactive protein rate and serum biomarkers indicative of myocardial injury. Systemic infection and/or active systemic juvenile idiopathicarthritiswereconsidered.Shewastreatedwithantibioticsand glucocorticoids.However,10dayslatershedevelopedactivesystemic disease(fever,evanescentrashandmyopericarditiswithsignsofheart failure)associatedwithmacrophageactivationsyndrome,accordingto the 2016ClassificationCriteriaforMacrophageActivationSyndromein SystemicJuvenileIdiopathicArthritis.Shewastreatedforfivedayswith pulsetherapy,usingglucocorticoids,immunoglobulinandcyclosporine A, with improvement of all clinical signs and laboratory tests. Comments: Myopericarditis with signs of heart failure associated with MAS is a rare clinical presentation of systemic juvenile idiopathic arthritis. Macrophage activation syndrome occurs mainly during periods of active systemic juvenile idiopathic arthritis and may be triggered by infection. Knowledge about this syndrome is crucial to reduce morbidity and mortality.