Sj. Marcus et Re. Ware, Physiologic decline in fetal hemoglobin parameters in infants with sickle cell disease: Implications for pharmacological intervention, J PED H ONC, 21(5), 1999, pp. 407-411
Purpose: Fetal hemoglobin (HbF) is an important determinant in the clinical
severity of patients with sickle cell disease. The physiologic decline in
HbF parameters in a cohort of infants with sickle cell disease was investig
ated.
Patients and Methods: The percent HbF and F cells were quantitated, and the
HbF per F cell was then calculated. One hundred thirty-eight blood samples
from 44 infants with homozygous sickle cell anemia (HbSS) and 56 samples f
rom 24 infants with sickle cell hemoglobin (HbSC) were studied.
Results: Infants with HbSS had a logarithmic decline in HbF parameters; at
24 months, the average HbF was 14.6% +/- 7.3% and the % F cells was 64.7% /- 16.9%. The amount of HbF in each F cell (HbF per F cell) was <15 pg/cell
, a suggested threshold for intracellular sickle polymerization, by age 12
months. Infants with HbSC had a more rapid decline: at 12 months the averag
e % HbF was 12.2% +/- 9.3%, the % F cells was 60.5% +/- 18.7%, and the HbF
per F cell was <10 pg/cell.
Conclusions: By age 2 years, HbF parameters including the % HbF, % F cells,
and the HbF per F cell decrease to levels insufficient to inhibit sickling
. Pharmacologic intervention designed to enhance HbF production and prevent
chronic organ damage should be considered during infancy.