Examination of Reticulocytosis among Chronically Transfused Children with Sickle Cell Anemia.
Sickle cell anemia (SCA) is an inherited hemolytic anemia with compensatory reticulocytosis. Recent studies have shown that increased levels of reticulocytosis during infancy are associated with increased hospitalizations for SCA sequelae as well as cerebrovascular pathologies. In this study, absolute reticulocyte counts (ARC) measured prior to transfusion were analysed among a cohort of 29 pediatric SCA patients receiving chronic transfusion therapy (CTT) for primary and secondary stroke prevention. A cross-sectional flow cytometric analysis of the reticulocyte phenotype was also performed. Mean duration of CTT was 3.1 ± 2.6 years. Fifteen subjects with magnetic resonance angiography (MRA) -vasculopathy had significantly higher mean ARC prior to initiating CTT compared to 14 subjects without MRA-vasculopathy (427.6 ± 109.0 K/μl vs. 324.8 ± 109.2 K/μl, p<0.05). No significant differences in hemoglobin or percentage sickle hemoglobin (HbS) were noted between the two groups at baseline. Reticulocyte phenotyping further demonstrated that the percentages of circulating immature [CD36(+), CD71(+)] reticulocytes positively correlated with ARC in both groups. During the first year of CTT, neither group had significant reductions in ARC. Among this group of children with SCA, cerebrovasculopathy on MRA at initiation of CTT was associated with increased reticulocytosis, which was not reduced after 12 months of transfusions.
Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.|Center for Cancer and Blood Disorders, Children's National Health System, Washington, D.C., United States of America.|Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America.
Megha
M
Kaushal
Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
Colleen
C
Byrnes
Division of Diagnostic Imaging and Radiology, Children's National Health System, Washington, D.C., United States of America.
Zarir
Z
Khademian
Indiana Hemophilia and Thrombosis Center, Indianapolis, Indiana, United States of America.
Natalie
N
Duncan
Center for Cancer and Blood Disorders, Children's National Health System, Washington, D.C., United States of America.|Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America.
Naomi L C
NL
Luban
Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
Jeffery L
JL
Miller
Center for Cancer and Blood Disorders, Children's National Health System, Washington, D.C., United States of America.|Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America.
Ross M
RM
Fasano
Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.|Center for Cancer and Blood Disorders, Children's National Health System, Washington, D.C., United States of America.|Department of Pediatrics, The George Washington University School of Medicine and Health Sciences, Washington, D.C., United States of America.
Emily Riehm
ER
Meier
D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000150:complications / Q000628:therapy*; D001803:Blood Transfusion / Q000379:methods; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography; D008297:Male; D017701:Reticulocyte Count; D045262:Reticulocytosis; D012189:Retrospective Studies; D020521:Stroke / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control; D055815:Young Adult