Objective. To assess the benefit of the recombinant human interleukin-1 receptor antagonist anakinra in treating pediatric patients with secondary hemophagocytic lymphohistiocytosis (HLH)/macrophage activation syndrome (MAS) associated with rheumatic and nonrheumatic conditions. Methods. A retrospective chart review of all anakinra-treated patients with secondary HLH/MAS was performed at Children's of Alabama from January 2008 through December 2016. Demographic, clinical, laboratory, and genetic characteristics, outcomes data, and information on concurrent treatments were collected from the records and analyzed using appropriate univariate statistical approaches to assess changes following treatment and associations between patient variables and outcomes.Results. Forty-four patients with secondary HLH/MAS being treated with anakinra were identified in the electronic medical records. The median duration of hospitalization was 15 days. The mean pretreatment serum ferritin level was 33,316 ng/ml and dropped to 14,435 ng/ml (57% decrease) within 15 days of the start of anakinra treatment. The overall mortality rate in the cohort was 27%. Earlier initiation of anakinra (within 5 days of hospitalization) was associated with reduced mortality (P = 0.046), whereas thrombocytopenia (platelet count <100,000/μl) and STXBP2 mutations were both associated with increased mortality (P = 0.008 and P = 0.012, respectively). In considering patients according to their underlying diagnosis, those with systemic juvenile idiopathic arthritis (JIA) had the lowest mortality rate, with no deaths among the 13 systemic JIA patients included in the study (P = 0.006). In contrast, those with an underlying hematologic malignancy had the highest mortality rate, at 100% (n = 3).Conclusion. These findings suggest that anakinra appears to be effective in treating pediatric patients with non-malignancy-associated secondary HLH/MAS, especially when it is given early in the disease course and when administered to patients who have an underlying rheumatic disease.ClinicalTrials.gov identifier: NCT02780583.

ObjectiveMacrophage activation syndrome (MAS) is a life‐threatening complication of systemic juvenile idiopathic arthritis (sJIA). Early diagnosis is critical. Classification criteria for MAS in sJIA perform less well in the setting of cytokine‐directed therapies. The goal herein was to explore a simple ratio of serum ferritin to the erythrocyte sedimentation rate (ESR) for diagnosis of MAS in the setting of sJIA, and to assess ferritin alone as a screening tool for identifying MAS of multiple etiologies.MethodsData from a large international cohort of sJIA patients with and without MAS, and from hospitalized patients with systemic infection (SI), were assessed for the ferritin:ESR ratio and ferritin alone to identify MAS among sJIA patients. Moreover, data from a smaller cohort of MAS patients associated with multiple etiologies and febrile hospitalized controls were explored. For both cohorts and controls, receiver operating characteristic curves (ROCs) for the ferritin:ESR ratio and ferritin alone were constructed, and areas under the curves (AUCs) were calculated. The Youden index was used to determine the optimal ferritin:ESR ratio and ferritin alone cut points for diagnosis.ResultsA ferritin:ESR ratio of 21.5 was 82% sensitive and 78% specific for diagnosing sJIA‐MAS versus active sJIA without MAS. Ferritin alone with a set sensitivity of 95% (screening tool) had an 89.3% specificity of identifying all‐cause MAS versus febrile hospitalized children.ConclusionThe ferritin:ESR ratio is a practical tool for diagnosing MAS among sJIA patients, and serum ferritin alone is a remarkable screening tool for identifying MAS among febrile hospitalized children.

BackgroundHenoch-Schonlein purpura (HSP) is a small vessel vasculitis that is characterized by non-thrombocytopenic purpura, abdominal pain, arthritis, and glomerulonephritis. Typically, HSP is self-limited requiring only supportive care, but more severe cases may require corticosteroid (CS) treatment. Rarely, a subset of these patients has persistent rash, arthritis, abdominal involvement, or renal disease despite treatment with CS, or has disease recurrence on CS tapering. Refractory HSP has been effectively treated with a variety of CS sparing therapies. For life-threatening refractory HSP, the B cell depleting agent, rituximab (RTX), has been reported as beneficial for children with substantial renal or central nervous system involvement. However, RTX use for children with less severe HSP, but chronic CS dependent disease refractory to CS sparing immunomodulatory agents, has been less well explored. Herein, we describe 8 children treated with RTX for chronic refractory HSP and report a reduction in recurrent hospitalizations and eventual CS discontinuation.MethodsThis is a retrospective analysis of eight children who were treated with RTX for chronic CS dependent HSP during the years 2006–2014 at a single institution. A chart review of the electronic medical record was performed to determine the presenting symptoms, the type and duration of treatment received, and the number of hospitalizations prior to and after RTX. The number of hospitalizations and oral corticosteroid burden were analyzed using the Wilcoxon signed rank test.ResultsPrior to receiving RTX, seven patients had at least one hospitalization for HSP (median 1.5, range 0–3). Following RTX, only two patients were hospitalized, each a single time for recurrent abdominal pain. The median oral CS burden was 0.345 mg/kg/day before RTX and 0 mg/kg/day at 6 months (p = 0.078), 1 year (p = 0.0625), and 2 years (p = 0.03) following RTX infusion. Seven out of eight children met remission criteria, defined as no active rash, arthritis, nephritis (hematuria and proteinuria), or gastrointestinal distress following RTX. No serious adverse events were noted.ConclusionOverall, RTX effectively reduced the number of hospital admissions and oral CS burden. RTX also helped most all children achieve clinical remission. RTX appears to be an effective and safe alternative for chronic CS dependent and immunomodulatory refractory childhood HSP.