University of Florida College of Medicine, Gainesville, Florida, U.S.A.. Received 17 August 1998; accepted for publication 22 October 1998. Summary.
British Journal of Haematology, 1999, 104, 90–92
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Plasma thrombopoietin concentrations in thrombocytopenic and non-thrombocytopenic patients in a neonatal intensive care unit M A RT H A C. S O L A , DA R L E N E A. C A L H O U N , A L A N D. H U T S ON * AN D R OB E RT D. C H R I S T E N S E N Division of Neonatology, Department of Pediatrics, and *Division of Biostatistics, University of Florida College of Medicine, Gainesville, Florida, U.S.A. Received 17 August 1998; accepted for publication 22 October 1998
Summary. Thrombocytopenia is a frequent occurrence in the neonatal intensive care unit (NICU), but the role of thrombopoietin (Tpo) in the pathophysiology is unknown. We obtained serial plasma Tpo concentrations in 20 thrombocytopenic neonates in our NICU, and performed bone marrow studies in 15. The initial Tpo levels ranged from undetectable (130 × 109/l) admitted to Correspondence: Dr Robert D. Christensen, Division of Neonatology, University of Florida, College of Medicine, P.O. Box 100296, Gainesville, FL 32610-0296, U.S.A.
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Keywords: thrombopoietin, thrombocytopenia, newborn, neonatal thrombocytopenia, alloimmune thrombocytopenia.
RESULTS Tpo concentrations in non-thrombocytopenic neonates The 47 non-thrombocytopenic infants were 35 6 5 weeks gestation (26–42 weeks), and had platelet counts of 256 6 60 × 109/l (137–403 ×109/l). Their median Tpo q 1999 Blackwell Science Ltd
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concentration was 93 pg/ml (< 41–477 pg/ml). The 90th percentile was 162 pg/ml; therefore we defined all values between < 41 pg/ml (undetectable) and 162 pg/ml as ‘normal’. Tpo did not correlate with gestational age or platelet count. Tpo concentrations in thrombocytopenic neonates This group was composed of 14 preterm (24–36 weeks) and six term neonates. Three were small for gestational age (SGA). The age at the first recognition of thrombocytopenia ranged from 0 to 46 d, with 10 being thrombocytopenic at birth. The initial platelet counts were 58 6 23 × 109/l (16–97 × 109/l). The initial Tpo concentrations were ‘normal’ (
