Utility of Serum Biomarker Indices for Staging of Hepatic Fibrosis Before and After Venesection in Patients With Hemochromatosis Caused by Variants in HFE

Abstract

Hemochromatosis that is associated with variants in the homeostatic iron regulator gene (HFE) is characterized by intestinal absorption of iron and excessive body and hepatic iron stores; it can lead to hepatic fibrosis and cirrhosis. Fibrosis has been staged by analysis of liver biopsies, but non-invasive staging methods are available. We evaluated the ability of aspartate aminotransferase:platelet ratio index (APRI), the fibrosis-4 (FIB-4) index, and gamma-glutamyl transferase:platelet ratio (GPR) to assess hepatic fibrosis staging in subjects with HFE-associated hemochromatosis, using liver biopsy-staged fibrosis as the reference standard. We performed a retrospective, cross-sectional analysis of 181 subjects with HFE-associated hemochromatosis and hepatic fibrosis staged by biopsy analysis and available serum samples. We calculated APRI, FIB-4, and GPR at diagnosis for all 181 subjects and following venesection therapy in 64 of these subjects (7 subjects had follow-up biopsy analysis). We used area under the receiver operating characteristic curve (AUROC) analysis to assess the relationships between APRI score, FIB-4 score, and GPR and advanced (F3-F4) fibrosis and to select cut-off values. Hepatic fibrosis stage correlated with APRI score (r = 0.54; P < .0001), FIB-4 score (r = 0.35; P <.0001), and GPR (r = 0.36, P < .0001). An APRI score above 0.44 identified patients with advanced fibrosis with an AUROC of 0.88, 79.4% sensitivity, 79.4% specificity, and 81% accuracy. A FIB-4 score above 1.1 identified patients with advanced fibrosis with an AUROC of 0.86, 80% sensitivity, 80.3% specificity, and 81% accuracy. A GPR above 0.27 identified patients with advanced fibrosis with an AUROC of 0.76, 67.7% sensitivity, 70.3% specificity, and 69% accuracy. APRI score was significantly more accurate than GPR (P = .05) in detecting advanced fibrosis; there was no difference between APRI and FIB-4. Venesection treatment was associated with significant reductions in APRI (P < .0001) and GPR (P < .001), paralleling fibrosis regression observed in available liver biopsies. Post-venesection APRI identified 87% of subjects with advanced fibrosis that decreased to levels that indicate stage F1-F2 fibrosis. In a retrospective study of 181 subjects with HFE-associated hemochromatosis, we found that APRI and FIB-4 scores identified patients with advanced hepatic fibrosis with 81% accuracy. APRI scores might also be used to monitor fibrosis regression following venesection.