Macrophage Activation Syndrome in an Adolescent Male with Dialysis-Dependent Kidney Failure and Systemic Lupus Erythematosus Flares

Introduction: MAS is a life-threatening dysregulation of the immune system that progresses to multisystem organ failure. It occurs typically in systemic juvenile idiopathic arthritis (sJIA) & rarely in SLE. We describe a unique instance in an adolescent male with SLE who developed MAS. Case Description: This case is of a 17-year-old African American male with family history of severe SLE, diagnosed at age 12. He developed class IV lupus nephritis, deep vein thrombosis, & pulmonary embolism 2 years later. He failed therapy with Mycophenolate mofetil, Cyclophosphamide, Rituximab and Belimumab & was dialysis dependent in less than 1 year of kidney disease. Before the current illness, he had recurrent hypotension, pancytopenia, low complement, & high serological markers for 10 months. At presentation, he had fever, emesis, diarrhea & fluid-resistant hypotension. He recieved empiric antibiotics & pulse steroids, however, he developed respiratory failure, tonic-clonic seizure, hyperglycemia, and pancreatitis. Lab values were consistent with MAS (Fig 1), including HScore >250, signifying a >99% probability of MAS. MRI showed a chronic atrophic cerebral cortex. Infectious workup was negative. He responded to infusions of Anakinra. Discussion: Severe SLE was complicated by MAS in our patient which is rare. Recurrent hypotension before MAS, suspicious of cytokine storm, has not been described. Rapid involvement of the liver, pancreas, central nervous system and acute increase in ferritin lead to a diagnosis. Frequent relapses, chronic cytopenia, intense immunosuppression, & intractable hypotension may precede MAS as seen in our case. Early treatment may reverse clinical deterioration, improving survival.