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.

Background: The study aims to define the efficacy of continuous renal replacement therapy in acute metabolic decompensation treatment of maple syrup urine disease (MSUD). Methods: All the neonates, infants and children who have had life threatening conditions due to MSUD and were treated with continuous venovenous hemodiafiltration (CVVHDF) were analyzed retrospectively. Results: Fourteen patients underwent 15 sessions of CVVHDF (age range 15 days to 87 months, mean 40.8 ± 31.4 months). One patient required additional CVVHDF 1 week after cessation of CVVHDF. Twenty seven percent (n = 4) of the patients were intubated and mechanically ventilated. Twelve patients responded to treatment and dramatic neurological improvement was observed within 24 h. Two of the 14 patients required 36 h of CVVHDF for neurological improvement. The mean duration of CVVHDF was 20.2 ± 8.6 (9-36) h. The mean leucine level was 1,648 ± 623.8 (714-2,768) μmol/l before and was 256.5 ± 150.6 (117-646) μmol/l at the end of treatment. No mortality was observed. Conclusion: Continuous hemodiafiltration is an effective and safe method in correcting metabolic disturbances in MSUD.

Background: The aim of this study was to evaluate the outcomes of patients with the multisystem inflammatory syndrome in children (MIS-C) according to phenotypes of disease and define the prognostic factors for the severe course. Methods: This cross-sectional study included 293 patients with MIS-C from seven pediatric rheumatology centers. A two-step cluster analysis was performed to define the spectrum of disease and their outcomes were compared between each group. Results: Four subgroups were identified as follows: cluster I, predominantly Kawasaki-like features (n = 100); cluster II, predominantly MAS-like features (n = 34); cluster III, predominantly LV dysfunction (n = 47); cluster IV, other presentations (n = 112). The duration of fever was longer in cluster II and the length of hospitalization was longer in both clusters II and III. Laboratory findings revealed lower lymphocyte and platelet counts and higher acute phase reactants (APRs) in cluster II, while patients in cluster IV showed less inflammation with lower APRs. The resolution of abnormal laboratory findings was longer in clusters II and III, while it was shortest in cluster IV. Seven patients died. Among them, four belonged to cluster II, while three were labeled as cluster III. Patients with severe course had higher levels of neutrophil–lymphocyte ratio, mean platelet volume, procalcitonin, ferritin, interleukin-6, fibrinogen, D-Dimer, BNP, and troponin-I, and lower levels of lymphocyte and platelet counts. Conclusion: As shown, MIS-C is not a single disease presenting with various clinical features and outcomes. Understanding the disease spectrum will provide individualized management.