title: [Haemophagocytic syndrome: A common pathogenic mechanism of various aetiologies].
abstract: BACKGROUND
  Haemophagocytic syndrome (HPS) is a rare syndrome characterised by the uncontrolled activation and proliferation of histiocytes and T cells, leading to a cytokines overproduction. There are two forms of HPS: primary and secondary.
  
  
  OBJECTIVE
  To analyse patients diagnosed with HPS at the Oncohaematology Department, using HLH-94 and 2004 protocol diagnostic criteria.
  
  
  METHODS
  Retrospective study of clinical files of patients diagnosed with HPS, analysing the following features: diagnostic criteria, variability in clinical presentation, aetiology, treatment and outcome.
  
  
  RESULTS
  Twenty-two patients were diagnosed with HPS: 6 familial haemophagocytic lymphohistiocytosis (FHL), 11 HPS with evidence of infection, 3 HPS associated with malignant disease and 2 macrophage activation syndrome (MAS) in patients with Crohn's disease and Juvenile Idiopathic Arthritis. The onset of FHL was within 1 year of age in 83.3%, except for 1 patient who was adolescent (MUNC13-4 mutations).
  
  
  METHODS
  All patients (100%) had fever at diagnosis, 18 (85%) hepatosplenomegaly, 7 (31%) lymphadenopathy, 5 (21%) pallor, 3 (14%) rash and 3 (14%) neurological symptoms.
  all patients (100%) had cytopenias at diagnosis, 20 (90.9%) hypertriglyceridaemia, 19 (86%) hyperferritinaemia, 17 (77%) elevated serum liver enzymes, and 9 (40%) hypofibrinogenaemia. Decreased or absent NK-cell activity was detected in all patients (100%). Haemophagocytosis was found more frequently in bone marrow; however, liver or lymph node biopsies were required in two patients to demonstrate this.
  
  
  RESULTS
  Of the ten patients (6 FHL, 3 Epstein-Barr virus-associated HPS and 1 MAS) treated with HLH-94 and 2004 protocols, six received a stem-cell transplant; of these, 2 with FHL had a favourable outcome. The remaining 12 patients received aetiological/supportive therapy, with complete remission in 83.3%.
  
  
  CONCLUSIONS
  The diagnosis of FHL should be made before the age of 2 years. Advances in genetic studies allow the detection of early and late forms of FHL. Immunochemotherapy and stem-cell transplantation constitute the treatment of FHL and aetiological/supportive therapy of acquired haemophagocytic lymphohistiocytosis, except in severe forms.
authors.affiliation: Servicio de Oncología y Hematología Pediátrica, Hospital Universitari Vall d'Hebron, Barcelona, España. jldapena@vhebron.net
authors.forename: J L
authors.initials: JL
authors.lastname: Dapena Díaz
authors.forename: C
authors.initials: C
authors.lastname: Díaz de Heredia Rubio
authors.forename: P
authors.initials: P
authors.lastname: Bastida Vila
authors.forename: A
authors.initials: A
authors.lastname: Llort Sales
authors.forename: I
authors.initials: I
authors.lastname: Elorza Alvarez
authors.forename: T
authors.initials: T
authors.lastname: Olivé Oliveras
authors.forename: J
authors.initials: J
authors.lastname: Sánchez de Toledo Codina
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D051359:Lymphohistiocytosis, Hemophagocytic / Q000175:diagnosis / Q000209:etiology* / Q000628:therapy; D008297:Male; D012189:Retrospective Studies