title: [Natural killer cell cytotoxic activity in critical pediatric patients with suspected hemophagocytic syndrome].
abstract: OBJECTIVE
  To determine the role of natural killer (NK) cytotoxic activity in patients with suspected hemophagocytic lymphohistiocytosis syndrome (HLH).
  
  
  METHODS
  A prospective study was conducted from September 2008 to February 2014.
  
  
  METHODS
  The study was carried out in the Hematological Oncology Laboratory of Hospital Infantil Universitario Niño Jesús, Madrid (Spain).
  
  
  METHODS
  We analyzed 30 peripheral blood samples from intensive care patients with suspected HLH. There were 18 males and 12 females, with a mean age of 4.7 years (range 0.2-22). NK cell cytotoxicity was compared with healthy controls according to age and sex.
  
  
  METHODS
  In vitro NK cell cytotoxicity against the K562 cell line was determined by time-resolved fluorescence (Europium-TDA) under resting conditions, after interleukin 15 stimulation, and following block with Fas ligand antibody.
  
  
  METHODS
  NK cell cytotoxicity.
  
  
  RESULTS
  A total of 20 patients showed a significant decrease of NK cell activity compared with controls (P=.001). Nine of these patients were diagnosed with primary HLH. A total of 10 patients were diagnosed with secondary HLH. Cytotoxic activity was normal in 10 subjects. None of them were diagnosed with HLH. Interleukin 15 stimulation increased NK cell cytotoxicity in secondary HLH, and blocking Fas ligand on NK cells decreased cytotoxic activity in primary HLH patients (P=.001).
  
  
  CONCLUSIONS
  In our experience, NK cell cytotoxic activity measured by time-resolved fluorescence is a simple and useful clinical diagnostic test for HLH. Interleukin 15 stimulation and Fas ligand blocking on NK cells could help differentiate between primary and secondary HLH.
authors: Hospital Montepríncipe, Madrid, España.
authors: I
authors: I
authors: Martínez
authors: Grupo de Investigación Clínica, Centro Nacional de Investigaciones Oncológicas (CNIO), España.
authors: L
authors: L
authors: Fernández
authors: Grupo de Inmunidad Innata y Cáncer, Instituto de Investigación de La Paz (IdiPaz), España.
authors: J
authors: J
authors: Valentín
authors: Universidad Autónoma de Madrid, Madrid, España.
authors: C
authors: C
authors: Castillo
authors: Faculty of Kinesiology, University of Calgary, Toronto, Canadá
authors: C
authors: C
authors: Chamorro
authors: Servicio de Hemato-Oncología Pediátrica, Hospital Universitario La Paz, Universidad Autónoma de Madrid, Madrid, España. Electronic address: aperezmartinez@salud.madrid.org.
authors: A
authors: A
authors: Pérez-Martínez
mesh_terms: D000293:Adolescent; D002644:Chickenpox / Q000150:complications; D002648:Child; D002675:Child, Preschool; D003141:Communicable Diseases / Q000175:diagnosis / Q000276:immunology; D016638:Critical Illness; D003602:Cytotoxicity, Immunologic; D003937:Diagnosis, Differential; D005199:Fanconi Anemia / Q000175:diagnosis / Q000276:immunology; D053222:Fas Ligand Protein / Q000037:antagonists & inhibitors / Q000276:immunology; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000150:complications / Q000628:therapy; D007223:Infant; D019409:Interleukin-15 / Q000494:pharmacology; D020014:K562 Cells; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology*; D051359:Lymphohistiocytosis, Hemophagocytic / Q000175:diagnosis / Q000209:etiology / Q000235:genetics / Q000276:immunology*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D051938:Munc18 Proteins / Q000235:genetics; D055815:Young Adult
chemical_list: C505661:FASLG protein, human; D053222:Fas Ligand Protein; D019409:Interleukin-15; D008565:Membrane Proteins; D051938:Munc18 Proteins; C497940:STXBP2 protein, human; C507969:UNC13D protein, human
keywords: Citotoxicidad de las células natural killer; Células natural killer; Fas ligand; Fas ligando; Hemophagocytic lymphohistiocytosis syndromes; Natural killer cells; Natural killer cytotoxicity; Síndromes hemofagocíticos