title: TLR-2 and TLR-4 expression in monocytes of newborns with late-onset sepsis.
abstract: OBJECTIVE
  To analyze toll-like receptor (TLR)-2 and TLR-4 expression in monocytes of newborns with late-onset sepsis.
  
  
  METHODS
  This prospective study included 27 full-term newborns aged 8 to 29 days, with clinical and laboratory diagnosis of late-onset sepsis. Ten newborns (37%) had positive cultures. Cytokines were measured by cytometric bead array in peripheral blood, while TLR-2, TLR-4 expression, and median fluorescence intensity (MFI) were determined by immunophenotyping peripheral whole blood monocytes, and were analyzed with a BD FACSDiva flow cytometer (Becton, Dickinson and Company, USA). A comparison was performed with healthy adults.
  
  
  RESULTS
  Microorganisms were identified in 37% of these septic newborns, and all of them had high levels of pro-inflammatory cytokines (IL-8, IL-6, IL-1β) and anti-inflammatory cytokine (IL-10) corroborating the inflammatory/septic process. In monocytes, the frequency of TLR-4 expression was higher in infected newborns (p = 0.01).
  
  
  CONCLUSIONS
  This study investigated the innate immune response in septic newborns. Septic newborns that relied almost exclusively on the innate immune system showed little in vivo response at monocyte activation, suggesting impaired immune response and increased susceptibility to infection.
authors.affiliation: Neonatal Intensive Care Unit, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Ana C C
authors.initials: AC
authors.lastname: Redondo
authors.affiliation: Neonatal Intensive Care Unit, Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil. Electronic address: maria.esther@hc.fm.usp.br.
authors.forename: Maria E J R
authors.initials: ME
authors.lastname: Ceccon
authors.affiliation: Department of Parasitology, Instituto de Ciências Biomédicas, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Silveira-Lessa
authors.affiliation: Laboratory of Medical Investigation (LIM-36), Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Quinello
authors.affiliation: Laboratory of Medical Investigation (LIM-36), Instituto da Criança, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Patrícia
authors.initials: P
authors.lastname: Palmeira
authors.affiliation: Department of Neonatology, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Werther B
authors.initials: WB
authors.lastname: Carvalho
authors.affiliation: Department of Pediatrics, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Magda
authors.initials: M
authors.lastname: Carneiro-Sampaio
mesh_terms: D016207:Cytokines / Q000097:blood*; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D016130:Immunophenotyping; D007231:Infant, Newborn; D008297:Male; D009000:Monocytes / Q000276:immunology; D011446:Prospective Studies; D018805:Sepsis / Q000276:immunology*; D047929:Term Birth; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism*
chemical_list: D016207:Cytokines; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4
keywords: Imunidade inata; Innate immunity; Monocytes; Monócitos; Newborn; Receptor 2 toll-like; Receptor 4 toll-like; Recém-nascidos; Sepse/imunologia; Sepsis/immunology; Toll-like receptor 2; Toll-like receptor 4