title: Respiratory syncytial virus-positive bronchiolitis in hospitalized infants is associated with thrombocytosis.
abstract: BACKGROUND
  Secondary thrombocytosis is associated with a variety of clinical conditions, one of which is lower respiratory tract infection. However, reports on thrombocytosis induced by viral infections are scarce.
  
  
  OBJECTIVE
  To assess the rate of thrombocytosis (platelet count > 500 x 10(9)/L) in hospitalized infants with bronchiolitis and to investigate its potential role as an early marker of respiratory syncytial virus infection.
  
  
  METHODS
  Clinical data on 469 infants aged < or = 4 months who were hospitalized for bronchiolitis were collected prospectively and compared between RSV-positive and RSV-negative infants.
  
  
  RESULTS
  The rate of thrombocytosis was significantly higher in RSV-positive than RSV-negative infants (41.3% vs. 29.2%, P=0.031). The odds ratio of an infant with bronchiolitis and thrombocytosis to have a positive RSV infection compared to an infant with bronchiolitis and a normal platelet count was 1.7 (P= 0.023, 95% confidence interval 1.07-2.72). There was no significant difference in mean platelet count between the two groups.
  
  
  CONCLUSIONS
  RSV-positive bronchiolitis in hospitalized young infants is associated with thrombocytosis.
authors.affiliation: Department of Pediatrics C, Schneider Children's Medical Center of Israel, Petah Tikva, and Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel. yoji@netvision.net.il
authors.forename: Efraim
authors.initials: E
authors.lastname: Bilavsky
authors.forename: Havatzelet
authors.initials: H
authors.lastname: Yarden-Bilavsky
authors.forename: Dror S
authors.initials: DS
authors.lastname: Shouval
authors.forename: Naama
authors.initials: N
authors.lastname: Fisch
authors.forename: Ben-Zion
authors.initials: BZ
authors.lastname: Garty
authors.forename: Shai
authors.initials: S
authors.lastname: Ashkenazi
authors.forename: Jacob
authors.initials: J
authors.lastname: Amir
mesh_terms: D001990:Bronchiolitis, Viral / Q000097:blood* / Q000150:complications / Q000821:virology; D016022:Case-Control Studies; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007557:Israel; D008297:Male; D010976:Platelet Count; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D018113:Respiratory Syncytial Virus, Human; D013922:Thrombocytosis / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology*