Differences in the Genomic Profiles of Immunoparalyzed and Nonimmunoparalyzed Children With Sepsis: A Pilot Study.

OBJECTIVES: Sepsis-induced immunoparalysis represents a pathologic downregulation of leukocyte function shown to be associated with adverse outcomes, although its mechanisms remain poorly understood. Our goal was to compare genome-wide gene expression profiles of immunoparalyzed and nonimmunoparalyzed children with sepsis to identify genes and pathways associated with immunoparalysis. DESIGN: Prospective observational study. PATIENTS: Twenty-six children with lower respiratory tract infection meeting criteria for sepsis, severe sepsis, or septic shock admitted to the PICU. SETTING: Two tertiary care PICUs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Innate immune function was assayed ex vivo by measuring release of tumor necrosis factor-α from whole blood after incubation with lipopolysaccharide for 4 hours. Immunoparalysis was defined as a tumor necrosis factor-α production capacity less than 200 pg/mL. Ten of the 26 children were immunoparalyzed. There were 17 significant differentially expressed genes when comparing genome-wide gene expression profiles of immunoparalyzed and nonimmunoparalyzed children (false discovery rate < 0.05). Nine genes showed increased expression in immunoparalyzed children (+1.5- to +8.8-fold change). Several of these dampen the immune system. Eight showed decreased expression in immunoparalyzed children (-1.7- to -3.9-fold change), several of which are involved in early regulation and activation of immune function. Functional annotation clustering using differentially expressed genes with p value of less than 0.05 showed three clusters related to immunity with significant enrichment scores (2.2-4.5); the most significant gene ontology terms in these clusters were antigen processing and presentation and negative regulation of interleukin-6 production. Network analysis identified potential protein interactions that may be involved in the development of immunoparalysis in children. CONCLUSIONS: In this exploratory analysis, immunoparalyzed children with sepsis showed increased expression of genes that dampen the immune system and decreased expression of genes involved in regulation and activation of the immune system. Analysis also implicated other proteins as potentially having as yet unidentified roles in the development of immunoparalysis.

Infectious and Noninfectious Acute Pericarditis in Children: An 11-Year Experience.

OBJECTIVE: The study was undertaken to determine the etiology, review management, and outcome in children diagnosed with acute pericarditis during 11 years at tertiary pediatric institution. METHODS: Retrospective chart review of children diagnosed between 2004 and 2014. Patients with postsurgical pericardial effusions were excluded. RESULTS: Thirty-two children were identified (median age 10yr/11mo). Pericardiocentesis was performed in 24/32 (75%) patients. The most common cause of pericarditis was infection in 11/32 (34%), followed by inflammatory disorders in 9 (28%). Purulent pericarditis occurred in 5 children including 4 due to Staphylococcus aureus: 2 were methicillin resistant (MRSA). All patients with purulent pericarditis had concomitant infection including soft tissue, bone, or lung infection; all had pericardial drain placement and 2 required pericardiotomy and mediastinal exploration. Other infections were due to Histoplasma capsulatum (2), Mycoplasma pneumoniae (2), Influenza A (1), and Enterovirus (1). Pericarditis/pericardial effusion was the initial presentation in 4 children with systemic lupus erythematosus including one who presented with tamponade and in 2 children who were diagnosed with systemic onset juvenile inflammatory arthritis. Tumors were diagnosed in 2 patients. Five children had recurrent pericarditis. Systemic antibiotics were used in 21/32 (66%) and prednisone was used in 11/32 (34%) patients. CONCLUSION: Infections remain an important cause of pericarditis in children. Purulent pericarditis is most commonly caused by Staphylococcus aureus and is associated with significant morbidity, need of surgical intervention, and prolonged antibiotic therapy. Echocardiography-guided thoracocentesis remains the preferred diagnostic and therapeutic approach. However, pericardiotomy and drainage are needed when appropriate clinical response is not achieved with percutaneous drainage.