Therapeutic Role of Anakinra, an Interleukin-1 Receptor Antagonist, in the Management of Secondary Hemophagocytic Lymphohistiocytosis/Sepsis/Multiple Organ Dysfunction/Macrophage Activating Syndrome in Critically Ill Children*

OBJECTIVES: Secondary hemophagocytic lymphohistiocytosis, macrophage activating syndrome, and sepsis share the same inflammatory phenotype leading often to multiple organ dysfunction syndrome needing intensive care. The goal of this article is to describe our experience with anakinra (Kineret), a recombinant interleukin-1 receptor antagonist, in decreasing the systemic inflammation. DESIGN: Retrospective case series. SETTING: The PICU at the Helen DeVos Children's Hospital (Grand Rapids, MI). PATIENTS: The records of eight critically ill children presumed to have secondary hemophagocytic lymphohistiocytosis at our institution between January 1, 2011, and July 31, 2012, were reviewed. INTERVENTIONS: All of the patients were treated with anakinra (Kineret) and in some cases systemic corticosteroids as first-line therapy for secondary hemophagocytic lymphohistiocytosis. MEASUREMENTS AND MAIN RESULTS: Patients had a median age of 14 years and a median Pediatric Risk of Mortality score of 11.5. Four were previously healthy and four had underlying diseases that could have made them susceptible to secondary hemophagocytic lymphohistiocytosis. Indications for PICU transfer were respiratory distress 50% (4 of 8), cardiovascular instability 37.5% (3 of 8), and chest pain (1 of 8). Five of the patients (62.5%) were mechanically ventilated and 62.5% (5 of 8) received vasoactive infusions. Inflammatory markers were assessed linearly at the start of therapy and 7 days later. Baseline C-reactive protein was 206 ± 50 mg/L (mean ± SEM) at the start of anakinra and decreased by 67.1% to 68 ± 36 mg/L (p = 0.03). Ferritin decreased by 63.8% to 3,210 ± 1,178 ng/mL (p = 0.30), and fibrinogen decreased by 42% to 158 ± 41 mg/dL (p = 0.03). Absolute neutrophil count (p = 0.38) and absolute lymphocyte count (p = 0.69) did not change significantly. No infections were attributed to anakinra therapy. One patient died long after treatment with anakinra while receiving pre-hematopoietic stem cell transplant chemotherapy. CONCLUSIONS: Anakinra could represent a promising therapeutic approach in these life-threatening disorders that are likely underdiagnosed and often difficult to treat.