(1524) Survival With Favorable Neurologic Outcome After VA ECMO for Hemophagocytic Lymphohistiocytosis

Introduction: Hemophagocytic Lymphohistiocytosis (HLH) is a rare syndrome where immune hyperactivation leads to multiorgan failure. Untreated, HLH has an 80% mortality rate, with HLH secondary to malignancy having the worst outcomes. Veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) can be used in severe cases. Survival remains poor, in part due to immunosuppressive treatments. To our knowledge, there are no reports of survival after ECMO for pediatric cardiovascular collapse due to HLH. We report a child with lymphoma-induced HLH who survived with favorable neurologic outcome after VA-ECMO.

Description: A 12-year-old previously healthy male was admitted to the pediatric intensive care unit with cardiovascular and respiratory failure. He had experienced prolonged fever, weight loss, and back pain, and was referred to the hospital for pulmonary nodules. On hospital day (HD) 1, vasoactive support rapidly escalated. He had a brief bradycardic arrest and was cannulated to VA-ECMO for circulatory failure. HLH was suspected, however, the patient only met four of eight criteria: fever, cytopenia, hepatosplenomegaly, and hyperferritinemia (1136 ng/mL). Given high clinical suspicion and severe illness, chemotherapeutic-sparing HLH treatment was started with Anakinra and steroids prior to definitive diagnosis. His soluble IL2 receptor peaked at 61,282 U/mL, supporting an HLH diagnosis. The child was liberated from ECMO on HD10. He was later discharged without apparent morbidity. Genetic testing showed a variant of undetermined significance in possibly HLH-associated genes. Three weeks after discharge, when he completed steroids, he presented with lymphadenopathy. Biopsy confirmed ALK+ anaplastic large cell lymphoma which likely triggered secondary HLH. He since has completed chemotherapy without comorbidities.

Discussion: HLH is rare and often lethal. A 31-year review of the Extracorporeal Life Support Organization registry found no cases of survival in children supported with VA-ECMO for cardiovascular failure due to HLH. This case is notable for both survival and favorable neurologic outcome. Aggressive treatment is warranted in children with possible HLH, who should be considered ECMO candidates given advances in therapy with diminished immunosuppression and the possibility of survival.