title: Platelet count may impact on lysosomal acid lipase activity determination in dried blood spot.
abstract: BACKGROUND
  We aimed to evaluate the influence of white blood cell (WBC) and platelet (PLT) counts on dried blood spot (DBS)-determined lysosomal acid lipase (LAL) activity in a large group of healthy subjects.
  
  
  METHODS
  One-hundred-and-seventy-two healthy subjects aged ≥18 were enrolled. Complete clinical biochemistry and LAL activity in DBS were determined. In 35 subjects, WBCs and PLTs were isolated, and LAL activity was measured in both blood cell populations. Univariate and multivariate analyses to DBS-LAL activity were performed.
  
  
  RESULTS
  Mean age of subjects was 44.8±17.2years, 43.6% were males, and mean DBS-LAL activity was normal (1.0±0.3nmol/spot/h). LAL activity in WBCs was significantly higher than in PLTs (458.9±133.6 vs 235.0±88.3nmol/mg/h, p<0.001). However, LAL activity in DBS correlated more strongly with that in PLTs (r=0.65, p<0.001) than with that in WBCs (r=0.49, p<0.01). Consistently, in the multivariate model, DBS-LAL activity was independently associated only with PLT count (β=0.39, p<0.001).
  
  
  CONCLUSIONS
  PLT number may impact on the result of the DBS-LAL test, and a consideration of PLT count is recommended before interpreting LAL activity in DBS.
authors.affiliation: Internal Medicine and Hepatology Unit, University Campus Bio-Medico, Rome, Italy. Electronic address: u.vespasiani@unicampus.it.
authors.forename: Umberto
authors.initials: U
authors.lastname: Vespasiani-Gentilucci
authors.affiliation: Unit of Neuromuscular and Neurodegenerative Diseases, Children's Hospital and Research Institute "Bambino Gesù", Rome, Italy.
authors.forename: Jessica
authors.initials: J
authors.lastname: D'Amico
authors.affiliation: Internal Medicine and Hepatology Unit, University Campus Bio-Medico, Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: De Vincentis
authors.affiliation: Unit of Neuromuscular and Neurodegenerative Diseases, Children's Hospital and Research Institute "Bambino Gesù", Rome, Italy.
authors.forename: Giulia
authors.initials: G
authors.lastname: Tozzi
authors.affiliation: Internal Medicine and Hepatology Unit, University Campus Bio-Medico, Rome, Italy.
authors.forename: Ferruccio
authors.initials: F
authors.lastname: Vorini
authors.affiliation: Internal Medicine and Hepatology Unit, University Campus Bio-Medico, Rome, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Gallo
authors.affiliation: Laboratory of Microscopic and Ultrastructural Anatomy, CIR, University Campus Bio-Medico, Rome, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Carotti
authors.affiliation: Laboratory of Microscopic and Ultrastructural Anatomy, CIR, University Campus Bio-Medico, Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Valentini
authors.affiliation: Internal Medicine and Hepatology Unit, University Campus Bio-Medico, Rome, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Galati
authors.affiliation: Internal Medicine and Hepatology Unit, University Campus Bio-Medico, Rome, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: dell'Unto
authors.affiliation: Unit of Neuromuscular and Neurodegenerative Diseases, Children's Hospital and Research Institute "Bambino Gesù", Rome, Italy.
authors.forename: Fiorella
authors.initials: F
authors.lastname: Piemonte
authors.affiliation: Internal Medicine and Hepatology Unit, University Campus Bio-Medico, Rome, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Picardi
mesh_terms: D000328:Adult; D016477:Artifacts; D001774:Blood Chemical Analysis / Q000592:standards*; D059788:Dried Blood Spot Testing / Q000592:standards*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D012044:Regression Analysis; D002787:Sterol Esterase / Q000097:blood*
chemical_list: D002787:Sterol Esterase
keywords: Dried blood spot; Lysosomal acid lipase; Platelets; White blood cells