Predictors of splenic function preservation in children with sickle cell anemia treated with hydroxyurea

Area of Science:

• Pediatric Hematology
• Sickle Cell Disease Research
• Pharmacological Interventions

Background:

• Over 90% of children with sickle cell anemia (SCA) lose splenic function by age two.
• Previous studies on hydroxyurea's effect on splenic function in SCA are conflicting.
• This study prospectively evaluates hydroxyurea's impact on splenic filtrative function.

Purpose of the Study:

• To assess the effect of hydroxyurea on splenic filtrative function in children with SCA.
• To identify factors associated with preserved or improved splenic function during hydroxyurea therapy.

Main Methods:

• Children with SCA were enrolled in the Hydroxyurea Study of Long-Term Effects (HUSTLE).
• Tc(99)m liver-spleen (LS) scans were performed before and after three years of hydroxyurea treatment.
• LS scans were classified based on splenic uptake: none, <10%, ≥10%, and normal.

Main Results:

• After three years, 33% of children (13 out of 40) demonstrated splenic uptake on LS scans.
• Children with splenic uptake were younger, had higher baseline and post-treatment HbF levels, and achieved maximum tolerated dose (MTD) faster.
• Baseline splenic uptake was a significant predictor of favorable outcome.

Conclusions:

• Hydroxyurea at MTD is linked to preserved or improved splenic function in children with SCA.
• Thirty-three percent of patients showed splenic uptake after three years of hydroxyurea therapy.
• Younger age, higher HbF, and baseline splenic function are associated with positive outcomes.