Aim: Although non-alcoholic fatty liver disease (NAFLD) is now a common cause of chronic liver disease, discriminating between simple steatosis and non-alcoholic steatohepatitis (NASH), especially early-stage NASH, remains difficult. We investigated the clinical usefulness of measuring the spleen volume as a marker of early-stage NASH.
Methods: We evaluated computed tomography (CT) images obtained in 84 patients with histologically diagnosed NAFLD (22 with simple steatosis, 62 with NASH with mild fibrosis [stages 1-2]). We defined the data obtained by the following formula as a spleen-body index (SBI): SBI = maximal CT axial section area of the spleen (cm(2))/body surface area (BSA) (cm(2)) x 10(4). We compared the SBI between patients with simple steatosis and those with NASH with mild fibrosis.
Results: The mean SBI of the simple steatosis group was 15.8 +/- 3.9, while that of the NASH with mild fibrosis group was 18.7 +/- 5.7. This difference between the two groups was significant (P = 0.0314). A multiple logistic regression analysis showed that the SBI was significantly correlated with the discrimination of simple steatosis and NASH with mild fibrosis. The area under the receiver-operator curve was 0.661 for distinguishing between simple steatosis and NASH with mild fibrosis (P = 0.026, 95% confidence interval = 0.532-0.789).
Conclusion: Spleen enlargement may be a distinct feature of NASH, especially early-stage NASH. SBI might be a non-invasive and simple method of differentiating NASH and simple steatosis.