Hepatic Iron Overload in Children With Sickle Cell Anemia on Chronic Transfusion Therapy

Abstract

Hepatic iron overload is a serious complication of chronic transfusion therapy in patients with sickle cell disease (SCD). No firm consensus has been reached with regard to correlation between hepatic iron content (HIC) and variables including age, number of transfusions, and serum iron makers. Also, the role of HIC in determining hepatic injury is not well established. There is scarcity of data on chronically transfused children with SCD and no other confounding liver pathology. We aimed to further explore relationships between these variables in a cohort of children with SCD on chronic transfusion therapy naive to chelation. Liver biopsies obtained before starting chelation therapy from 27 children with sickle cell anemia receiving chronic transfusion therapy were evaluated for histologic scoring and determination of HIC. Average serum ferritin and iron saturation values were determined for 6 months before biopsy. Duration and total volume of transfusion were obtained from the medical records. All children were negative for human immunodeficiency virus, hepatitis B virus, and hepatitis C virus infections. Mean age at biopsy was 10.95±3.34 years. Mean duration and total volume of transfusions were 50.0±26.6 months and 17.4±9.6 L, respectively. Pearson product-moment bivariate correlation coefficients indicated significant correlations between HIC and histologic iron score, serum ferritin, iron saturation, age, and transfusion volume. After adjusting for transfusion volume, a significant correlation was only seen between HIC and transfusion volume. Mean HIC was 21.8±10.4 mg/g dry weight, with fibrosis observed in 10 patients and lobular inflammation in 9. HIC was higher in biopsies with fibrosis (28.2±3.8 mg/g) than biopsies without fibrosis (17.6±18.3 mg/g; P=0.012). HIC did not differ between biopsies with lobular inflammation (25.5±4.0 mg/g) and biopsies without inflammation (19.9±2.5 mg/g; P=0.22). These findings show that transfusion volume provides more insight on hepatic iron overload than serum iron markers.