title: Predictors of splenic function preservation in children with sickle cell anemia treated with hydroxyurea.
abstract: BACKGROUND
  More than 90% of children with sickle cell anemia (SCA) lose splenic function by the age of 2 yrs. Splenic function may improve with hydroxyurea, but previous studies are conflicting. We prospectively evaluated the effect of hydroxyurea on splenic filtrative function.
  
  
  METHODS
  Children with SCA enrolled in the Hydroxyurea Study of Long-Term Effects (HUSTLE-NCT00305175) underwent clinical evaluations including Tc(99) m liver-spleen (LS) scans before hydroxyurea initiation and after 3 yrs of treatment to maximum tolerated dose (MTD). LS scans were classified as follows: no uptake, <10% uptake, decreased but ≥10% uptake, and normal.
  
  
  RESULTS
  Mean age (N = 40) was 9.1 yrs, range 2.3-17.0. After 3 yrs of treatment, 13 (33%) had uptake on LS scan. These 13 children were younger (median age 6.0 vs. 10.6 yrs, P = 0.008), had a higher HbF at baseline (mean 10.2% vs. 5.8%, P = 0.004) and after 3 yrs (22.9% vs. 13.9%, P < 0.001), achieved MTD more rapidly (median 288 vs. 358 d, P = 0.021), and were more likely to have baseline splenic uptake (P < 0.001).
  
  
  CONCLUSIONS
  Hydroxyurea at MTD is associated with preserved or improved splenic filtrative function, with 33% demonstrating LS scan uptake after 3 yrs. Younger age, higher %HbF, and baseline splenic function are associated with a favorable outcome.
authors.affiliation: Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN, USA.
authors.forename: Kerri A
authors.initials: KA
authors.lastname: Nottage
authors.forename: Russell E
authors.initials: RE
authors.lastname: Ware
authors.forename: Bryan
authors.initials: B
authors.lastname: Winter
authors.forename: Matthew
authors.initials: M
authors.lastname: Smeltzer
authors.forename: Winfred C
authors.initials: WC
authors.lastname: Wang
authors.forename: Jane S
authors.initials: JS
authors.lastname: Hankins
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Dertinger
authors.forename: Barry
authors.initials: B
authors.lastname: Shulkin
authors.forename: Banu
authors.initials: B
authors.lastname: Aygun
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000755:Anemia, Sickle Cell / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology; D000986:Antisickling Agents / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D005260:Female; D005319:Fetal Hemoglobin / Q000378:metabolism; D006801:Humans; D006918:Hydroxyurea / Q000627:therapeutic use*; D008099:Liver / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology; D008297:Male; D015609:Organotechnetium Compounds; D011446:Prospective Studies; D011877:Radionuclide Imaging; D013154:Spleen / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology
chemical_list: D000986:Antisickling Agents; D015609:Organotechnetium Compounds; C109881:dithio-bisphosphine tc99m; D005319:Fetal Hemoglobin; D006918:Hydroxyurea
keywords: hydroxyurea; sickle cell disease; splenic function