title: Serum thrombopoietin level and thrombocytopenia during the neonatal period in infants with Down's syndrome.
abstract: BACKGROUND
  The pathogenesis of thrombocytopenia during the neonatal period in Down's syndrome (DS) infants remains unclear.
  
  
  OBJECTIVE
  To elucidate kinetic changes of serum thrombopoietin (TPO) level and platelet count, and their correlation in DS neonates.
  
  
  METHODS
  Twelve DS infants (male/female: 7/5, term/late preterm: 10/2) born between 1997 and 2007 were included. Blood samples were serially collected during the neonatal period and serum TPO levels were determined in 44 sera using an enzyme-linked immunosorbent assay.
  
  
  RESULTS
  Thrombocytopenia <150 x 10(9) per liter was observed in seven (58%) patients. In 12 DS patients, the median TPO value showed 2.86 fmol ml(-1) on day 0, rose to 4.64 fmol ml(-1) on day 2, and thereafter decreased to 4.30 fmol ml(-1) on day 5, 2.40 fmol ml(-1) on days 11-15, and 1.75 fmol ml(-1) on days 28-30. This kinetics parallels that in historical non-DS controls. In 35 pair sample analysis from 11 patients without transient myeloproliferative disease, TPO level inversely correlated with platelet count (r=-0.38, P=0.023). However, there was no significant difference in TPO concentrations between thrombocytopenic and non-thrombocytopenic DS individuals.
  
  
  CONCLUSIONS
  This is the first study to describe the relationship between TPO level and platelet count in neonates with DS. Median TPO levels and their kinetic changes in DS neonates are comparable to those in non-DS controls. In contrast to earlier findings in several studies showing higher TPO concentrations in thrombocytopenic non-DS newborns than those in non-thrombocytopenic counterparts, the response of the TPO system to thrombocytopenia in DS during the neonatal period seems suboptimal.
authors.affiliation: Department of Pediatrics, Nishi-Kobe Medical Center, Kobe, Hyogo, Japan. kskmatsu@s4.dion.ne.jp
authors.forename: K
authors.initials: K
authors.lastname: Matsubara
authors.forename: H
authors.initials: H
authors.lastname: Nigami
authors.forename: K
authors.initials: K
authors.lastname: Yura
authors.forename: T
authors.initials: T
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Isome
authors.forename: T
authors.initials: T
authors.lastname: Fukaya
mesh_terms: D016022:Case-Control Studies; D004314:Down Syndrome / Q000097:blood*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D010976:Platelet Count; D013921:Thrombocytopenia / Q000097:blood* / Q000503:physiopathology; D013926:Thrombopoietin / Q000097:blood* / Q000502:physiology
chemical_list: D013926:Thrombopoietin