Hyperferritinemia in the critically ill child with secondary hemophagocytic lymphohistiocytosis/sepsis/multiple organ dysfunction syndrome/macrophage activation syndrome: what is the treatment?

INTRODUCTION Hyperferritinemia is associated with increased mortality in pediatric sepsis, multiple organ dysfunction syndrome (MODS), and critical illness. The International Histiocyte Society has recommended that children with hyperferritinemia and secondary hemophagocytic lymphohistiocytosis (HLH) or macrophage activation syndrome (MAS) should be treated with the same immunosuppressant/cytotoxic therapies used to treat primary HLH. We hypothesized that patients with hyperferritinemia associated secondary HLH/sepsis/MODS/MAS can be successfully treated with a less immunosuppressant approach than is recommended for primary HLH. METHODS We conducted a multi-center cohort study of children in Turkish Pediatric Intensive Care units with hyperferritinemia associated secondary HLH/sepsis/MODS/MAS treated with less immunosuppression (plasma exchange and intravenous immunoglobulin or methyl prednisolone) or with the primary HLH protocol (plasma exchange and dexamethasone or cyclosporine A and/or etoposide). The primary outcome assessed was hospital survival. RESULTS Twenty-three children with hyperferritinemia and secondary HLH/sepsis/MODS/MAS were enrolled (median ferritin = 6341 μg/dL, median number of organ failures = 5). Univariate and multivariate analyses demonstrated that use of plasma exchange and methyl prednisolone or intravenous immunoglobulin (n = 17, survival 100%) was associated with improved survival compared to plasma exchange and dexamethasone and/or cyclosporine and/or etoposide (n = 6, survival 50%) (P = 0.002). CONCLUSIONS Children with hyperferritinemia and secondary HLH/sepsis/MODS/MAS can be successfully treated with plasma exchange, intravenous immunoglobulin, and methylprednisone. Randomized trials are required to evaluate if the HLH-94 protocol is helpful or harmful compared to this less immune suppressive and cytotoxic approach in this specific population.