Objective To determine the efficacy of anakinra (recombinant interleukin-1 receptor antagonist) in improving 28-day survival in sepsis patients with features of macrophage activation syndrome (MAS). Despite equivocal results in sepsis trials, anakinra is effective in treating MAS, a similar entity with fever, disseminated intravascular coagulation (DIC), hepatobiliary dysfunction (HBD), cytopenias, and hyperferritinemia. Hence, sepsis patients with MAS features may benefit from IL-1 receptor blockade. Design Re-analysis of de-identified data from the phase III randomized interleukin-1 receptor antagonist trial in severe sepsis (Opal, et. al. Crit Care Med. 1997 Jul;25(7):1115–24). Setting Multi-center study recruiting through 91 centers from 11 countries in Europe and North America. Participants Sepsis patients with MODS and/or shock (original study) were re-grouped based on presence or absence of concurrent HBD and DIC as features of MAS (HBD/DIC group). The “non-HBD/DIC” group included patients with only HBD, only DIC or neither. Intervention Treatment with anakinra or placebo. Main Outcome(s) and Measure(s) 28-day mortality. Statistical analysis descriptive statistics, chi-square, ANOVA, logistic and Cox regression. Results Data were available for 763 adults from the original study cohort, randomized to receive either anakinra or placebo. Concurrent HBD/DIC was noted in 43 patients (5.6% of total, ages 18–75; 47% women). The 28-day survival was similar in both anakinra and placebo-treated non-HBD/DIC patients (71.4% vs. 70.8%, p=.88). Treatment with anakinra was associated with significant improvement in the 28-day survival rate in HBD/DIC patients (65.4% anakinra vs. 35.3% placebo), with HR for death 0.28 (0.11–0.71, p = 0.0071) for the treatment group in Cox regression. Conclusions and Relevance In this subgroup analysis, IL-1 receptor blockade was associated with significant improvement in survival of patients with sepsis and concurrent HBD/DIC. A prospective randomized trial using features of MAS for mortality risk stratification should be undertaken to confirm the role of IL-1 blockage.

are employees of and own stock in BioAegis Therapeutics, Inc. which is developing recombinant human plasma gelsolin for potential clinical use. Other authors have declared that no conflict of interest exists.

Objective To describe the clinical, laboratory, and histopathologic features, current treatment, and outcome of patients with macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (JIA). Methods In this multinational, multicenter study, pediatric rheumatologists and hemato‐oncologists entered patient data collected retrospectively into a web‐based database. Results A total of 362 patients, 22% of whom had MAS at the onset of systemic JIA, were included in the study by 95 investigators from 33 countries. The most frequent clinical manifestations were fever (96%), hepatomegaly (70%), and splenomegaly (58%). Central nervous system dysfunction and hemorrhages were recorded in 35% and 20% of the patients, respectively. Platelet count and liver transaminase, ferritin, lactate dehydrogenase, triglyceride, and d‐dimer levels were the sole laboratory biomarkers showing a percentage change of >50% between the pre‐MAS visit and MAS onset. Evidence of macrophage hemophagocytosis was found in 60% of the patients who underwent bone marrow aspiration. MAS occurred most frequently in the setting of active underlying disease, in the absence of a specific trigger. Nearly all patients were given corticosteroids, and 61% received cyclosporine. Biologic medications and etoposide were given to 15% and 12% of the patients, respectively. Approximately one‐third of the patients required admission to the intensive care unit (ICU), and the mortality rate was 8%. Conclusion This study provides information on the clinical spectrum and current management of systemic JIA–associated MAS through the analysis of a very large patient sample. MAS remains a serious condition, as a sizeable proportion of patients required admission to the ICU or died.

Eosinophil-mediated diseases, such as allergic asthma, eosinophilic fasciitis, and certain hypersensitivity pulmonary disorders, are characterized by eosinophil infiltration and tissue injury. Mast cells and T cells often colocalize to these areas. Recent data suggest that mast cells can contribute to eosinophil-mediated inflammatory responses. Activation of mast cells can occur by antigen and immunoglobulin E (IgE) via the high-affinity receptor (FcepsilonRI) for IgE. The liberation of proteases, leukotrienes, lipid mediators, and histamine can contribute to tissue inflammation and allow recruitment of eosinophils to tissue. In addition, the synthesis and expression of a plethora of cytokines and chemokines (such as granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin-1 [IL-1], IL-3, IL-5, tumor necrosis factor-alpha [TNF-alpha], and the chemokines IL-8, regulated upon activation normal T cell expressed and secreted [RANTES], monocyte chemotactic protein-1 [MCP-1], and eotaxin) by mast cells can influence eosinophil biology. Stem cell factor (SCF)-c-kit, cytokine-cytokine receptor, and chemokine-chemokine receptor (CCR3) interactions leading to nuclear factor kappaB (NF-kappaB), mitogen-activated protein kinase (MAPK) expression, and other signaling pathways can modulate eosinophil function. Eosinophil hematopoiesis, activation, survival, and elaboration of mediators can all be regulated thus by mast cells in tissue. Moreover, because eosinophils can secrete SCF, eosinophils can regulate mast cell function in a paracrine manner. This two-way interaction between eosinophils and mast cells can pave the way for chronic inflammatory responses in a variety of human diseases. This review summarizes this pivotal interaction between human mast cells and eosinophils.