title: Diagnostic criteria for hematopoietic stem cell transplant-associated microangiopathy: results of a consensus process by an International Working Group.
abstract: OBJECTIVE
  There are no widely accepted criteria for the definition of hematopoietic stem cell transplant -associated microangiopathy (TAM). An International Working Group was formed to develop a consensus formulation of criteria for diagnosing clinically significant TAM.
  
  
  METHODS
  The participants proposed a list of candidate criteria, selected those considered necessary, and ranked those considered optional to identify a core set of criteria. Three obligatory criteria and four optional criteria that ranked highest formed a core set. In an appropriateness panel process, the participants scored the diagnosis of 16 patient profiles as appropriate or not appropriate for TAM. Using the experts' ratings on the patient profiles as a gold standard, the sensitivity and specificity of 24 candidate definitions of the disorder developed from the core set of criteria were evaluated. A nominal group technique was used to facilitate consensus formation. The definition of TAM with the highest score formed the final
  
  
  METHODS
  
  
  
  RESULTS
  The Working Group proposes that the diagnosis of TAM requires fulfilment of all of the following criteria: (i) >4% schistocytes in blood; (ii) de novo, prolonged or progressive thrombocytopenia (platelet count <50 x 109/L or 50% or greater reduction from previous counts); (iii) sudden and persistent increase in lactate dehydrogenase concentration; (iv) decrease in hemoglobin concentration or increased transfusion requirement; and (v) decrease in serum haptoglobin. The sensitivity and specificity of this definition exceed 80%.
  
  
  CONCLUSIONS
  The Working Group recommends that the presented criteria of TAM be adopted in clinical use, especially in scientific trials.
authors.affiliation: Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland. tapani.ruutu@hus.fi
authors.forename: Tapani
authors.initials: T
authors.lastname: Ruutu
authors.forename: Giovanni
authors.initials: G
authors.lastname: Barosi
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Benjamin
authors.forename: Richard E
authors.initials: RE
authors.lastname: Clark
authors.forename: James N
authors.initials: JN
authors.lastname: George
authors.forename: Alois
authors.initials: A
authors.lastname: Gratwohl
authors.forename: Ernst
authors.initials: E
authors.lastname: Holler
authors.forename: Massimo
authors.initials: M
authors.lastname: Iacobelli
authors.forename: Karim
authors.initials: K
authors.lastname: Kentouche
authors.forename: Bernhard
authors.initials: B
authors.lastname: Lämmle
authors.forename: Joel L
authors.initials: JL
authors.lastname: Moake
authors.forename: Paul
authors.initials: P
authors.lastname: Richardson
authors.forename: Gerard
authors.initials: G
authors.lastname: Socié
authors.forename: Zella
authors.initials: Z
authors.lastname: Zeigler
authors.forename: Dietger
authors.initials: D
authors.lastname: Niederwieser
authors.forename: Tiziano
authors.initials: T
authors.lastname: Barbui
mesh_terms: D016026:Bone Marrow Transplantation / Q000009:adverse effects; D017408:Guidelines as Topic; D006242:Haptoglobins / Q000096:biosynthesis*; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006454:Hemoglobins / Q000096:biosynthesis*; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000096:biosynthesis*; D011697:Purpura, Thrombotic Thrombocytopenic / Q000175:diagnosis* / Q000209:etiology*; D012680:Sensitivity and Specificity; D014652:Vascular Diseases / Q000175:diagnosis* / Q000209:etiology*
chemical_list: D006242:Haptoglobins; D006454:Hemoglobins; D007770:L-Lactate Dehydrogenase