title: Expert consensus on dynamics of laboratory tests for diagnosis of macrophage activation syndrome complicating systemic juvenile idiopathic arthritis.
abstract: OBJECTIVE
  To identify which laboratory tests that change over time are most valuable for the timely diagnosis of macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (sJIA).
  
  
  METHODS
  A multistep process, based on a combination of expert consensus and analysis of real patient data, was conducted. A panel of experts was first asked to evaluate 115 profiles of patients with MAS, which included the values of laboratory tests at the pre-MAS visit and at MAS onset, and the change in values between the two time points. The experts were asked to choose the 5 laboratory tests in which change was most important for the diagnosis of MAS and to rank the 5 selected tests in order of importance. The relevance of change in laboratory parameters was further discussed and ranked by the same experts at a consensus conference.
  
  
  RESULTS
  Platelet count was the most frequently selected test, followed by ferritin level, aspartate aminotransferase (AST), white cell count, neutrophil count, and fibrinogen and erythrocyte sedimentation rate. Ferritin was most frequently assigned the highest score. At the end of the process, platelet count, ferritin level and AST were the laboratory tests in which the experts found change over time to be most important.
  
  
  CONCLUSIONS
  We identified the laboratory tests in which change over time is most valuable for the early diagnosis of MAS in sJIA. The dynamics of laboratory values during the course of MAS should be further scrutinised in a prospective study in order to establish the optimal cut-off values for their variation.
authors: Università degli Studi di Genova and Istituto Giannina Gaslini, Genoa, Italy; Istituto Giannina Gaslini, Genoa, Italy.
authors: Angelo
authors: A
authors: Ravelli
authors: Istituto Giannina Gaslini , Genoa , Italy.
authors: Francesca
authors: F
authors: Minoia
authors: Istituto Giannina Gaslini , Genoa , Italy.
authors: Sergio
authors: S
authors: Davì
authors: Karolinska Institute , Karolinska University Hospital Solna , Stockholm , Sweden.
authors: AnnaCarin
authors: A
authors: Horne
authors: Istituto Giannina Gaslini , Genoa , Italy.
authors: Francesca
authors: F
authors: Bovis
authors: Istituto Giannina Gaslini , Genoa , Italy.
authors: Angela
authors: A
authors: Pistorio
authors: Azienda Sanitaria Provinciale 7 , Ragusa , Italy.
authors: Maurizio
authors: M
authors: Aricò
authors: University Children's Hospital , Ljubljana , Slovenia.
authors: Tadej
authors: T
authors: Avcin
authors: The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania , USA.
authors: Edward M
authors: EM
authors: Behrens
authors: Ospedale Pediatrico Bambino Gesù , Rome , Italy.
authors: Fabrizio
authors: F
authors: De Benedetti
authors: Cincinnati Children's Hospital Medical Center , Cincinnati, Ohio , USA.
authors: Alexandra
authors: A
authors: Filipovic
authors: Albert Einstein College of Medicine and Children's Hospital at Montefiore , Bronx, New York , USA.
authors: Alexei A
authors: AA
authors: Grom
authors: Karolinska Institute , Karolinska University Hospital Solna , Stockholm , Sweden.
authors: Jan-Inge
authors: JI
authors: Henter
authors: Albert Einstein College of Medicine and Children's Hospital at Montefiore , Bronx, New York , USA.
authors: Norman T
authors: NT
authors: Ilowite
authors: Cincinnati Children's Hospital Medical Center , Cincinnati, Ohio , USA.
authors: Michael B
authors: MB
authors: Jordan
authors: Jaslok Hospital and Research Centre , Mumbai, Maharashtra , India.
authors: Raju
authors: R
authors: Khubchandani
authors: Aichi Medical University , Nagakute , Japan.
authors: Toshiyuki
authors: T
authors: Kitoh
authors: University Medical Center , Hamburg , Germany.
authors: Kai
authors: K
authors: Lehmberg
authors: Cincinnati Children's Hospital Medical Center , Cincinnati, Ohio , USA.
authors: Daniel J
authors: DJ
authors: Lovell
authors: University of Calgary , Calgary, Alberta , Canada.
authors: Paivi
authors: P
authors: Miettunen
authors: St Jude Children's Research Hospital , Memphis, Tennessee , USA.
authors: Kim E
authors: KE
authors: Nichols
authors: Hacettepe University , Ankara , Turkey.
authors: Seza
authors: S
authors: Ozen
authors: University Children's Hospital , Zurich , Switzerland.
authors: Jana
authors: J
authors: Pachlopnik Schmid
authors: Bristol Royal Hospital for Children , Bristol , UK.
authors: Athimalaipet V
authors: AV
authors: Ramanan
authors: Hospital de Pediatria Juan P Garrahan , Buenos Aires , Argentina.
authors: Ricardo
authors: R
authors: Russo
authors: University of Toronto and Hospital for Sick Children , Toronto, Ontario , Canada.
authors: Rayfel
authors: R
authors: Schneider
authors: Mount Sinai Medical Center , Miami Beach, Florida , USA.
authors: Gary
authors: G
authors: Sterba
authors: Meir Medical Centre , Kfar Saba , Israel.
authors: Yosef
authors: Y
authors: Uziel
authors: Seattle Children's Hospital and University of Washington , Seattle, Washington , USA.
authors: Carol
authors: C
authors: Wallace
authors: University Hospital Leuven , Leuven , Belgium.
authors: Carine
authors: C
authors: Wouters
authors: Wilhelmina Children's Hospital and University Medical Center Utrecht , Utrecht , The Netherlands.
authors: Nico
authors: N
authors: Wulffraat
authors: Gulhane Military Medical Faculty, Ankara , Turkey.
authors: Erkan
authors: E
authors: Demirkaya
authors: Cincinnati Children's Hospital Medical Center , Cincinnati, Ohio , USA.
authors: Hermine I
authors: HI
authors: Brunner
authors: Università degli Studi di Genova and Istituto Giannina Gaslini, Genoa, Italy; Istituto Giannina Gaslini, Genoa, Italy.
authors: Alberto
authors: A
authors: Martini
authors: Istituto Giannina Gaslini , Genoa , Italy.
authors: Nicolino
authors: N
authors: Ruperto
authors: University of Alabama at Birmingham , Birmingham, Alabama , USA.
authors: Randy Q
authors: RQ
authors: Cron
keywords: Epidemiology; Juvenile Idiopathic Arthritis; Outcomes research