The relationship between liver stiffness by two-dimensional shear wave
elastography and iron overload status in transfusion-dependent patients
Abstract
Background: Increased liver stiffness can be result of
increased liver iron concentration (LIC) which may not yet be reflected
in the liver fibrotic status. The objective of our study was to examine
relationship between hemochromatosis, liver stiffness, and serum
ferritin level in transfusion-dependent patients. Methods: All
transfusion-dependent patients aged between seven and 60 years referred
for evaluating LIC status by magnetic resonance imaging (MRI) followed
by two-dimensional ultrasonography shear wave elastography (2D-SWE) were
included in this study. Results: The optimal cut point for
prediction of severe hemochromatosis using median SWE (kPa) and SWV
(m/s) was ≥ 7.0 kPa and ≥ 1.54 m/s, respectively, with sensitivity of
0.76 (95% confidence interval [CI] 0.55, 0.91) and, specificity of
0.69 (95%CI 0.53, 0.82). When combing the optimal cut point of SWE
(kPa) at ≥ 7.0 and serum ferritin ≥ 4123 ng/mL, the sensitivity
increased to 0.84 (95%CI 0.64, 0.95) with specificity of 0.67 (95%CI
0.50, 0.80), positive predictive value (PPV) of 0.60 (95%CI 0.42,
0.76), and negative predictive value (NPV) of 0.88 (95%CI 0.71, 0.96).
Simultaneous tests of 2D-SWE and serum ferritin for prediction of severe
hemochromatosis showed the highest sensitivity of 84% (95%CI
0.64-0.95), as compared to 2D-SWE alone at 76% (95%CI 0.55, 0.91) or
serum ferritin alone at 44% (95%CI 0.24-0.65). Conclusions:
We recommend measuring both 2D-SWE and serum ferritin in short interval
follow up patients. Adding 2D-SWE to the management guideline will help
in deciding if aggressive adjustments of iron chelating medication in
indicated in patients suspicious for severe hemochromatosis.