Assessment of Liver Fibrosis by Transient Elastography in Children and Young Adults With Sickle Cell Disease With and Without Iron Overload

Abstract

Transfusion-associated iron overload may cause liver fibrosis. We compared transient elastography (TE) and aspartate aminotransferase-platelet ratio index (APRI), noninvasive markers for hepatic fibrosis, to liver histology in children and young adults with sickle cell disease (SCD) who were iron overloaded (cohort 1). Age-matched subjects with SCD but without iron overload (cohort 2) were enrolled for APRI and TE assessments. Nineteen subjects ages 10 to 21 years were transfused for a mean of 9.67 years, had a mean serum ferritin of 4899±2849 ng/mL, and a liver iron concentration of 15.56±10.12 mg/g dry liver weight by R2-magnetic resonance imaging. Mean APRI was 0.33±0.13 in cohort 1 and 0.27±0.10 in cohort 2. The mean liver stiffness measures (LSM) in cohort 1, assessed by TE, was 8.46±3.95 kPa, ranging from 3.5 to 14.6 kPa (expected normal <7 kPa). Cohort 2 had a mean LSM of 5.72±1.74 kPa (4.6 to 8.7 kPa). There was a good correlation between LSM and histologic fibrosis (t value 6.94, P<0.0001). There was no significant correlation between APRI and histologic fibrosis and between APRI and LSM. A high LSM suggests liver fibrosis in children and adults with SCD with iron overload and may merit histologic confirmation especially if persistent.