Levels of Alanine Aminotransferase Confound Use of Transient Elastography to Diagnose Fibrosis in Patients With Chronic Hepatitis C Virus Infection
Clinical Gastroenterology and Hepatology , 08/03/2012
Tapper EB et al. – In patients with hepatitis C virus (HCV) infection and early–stage fibrosis, increased levels of alanine aminotransferase (ALT) correlate with liver stiffness among patients in the lowest strata of fibrosis (METAVIR scores 0–2). Patients without fibrosis but high levels of ALT could have liver stiffness within the range for cirrhosis. Inflammation should be considered a confounding variable in analysis of liver stiffness.Methods
- The authors identified 684 patients with HCV and METAVIR fibrosis scores of 0-2 from a prospective, multi-institutional study of liver stiffness in 2880 patients with chronic liver disease.
- Patients were 49.6 ± 9.0 years old, 64.3% were male, and they had an average body mass index of 26.7 ± 4.1 kg/m2.
- In a multivariate analysis, inflammation (based on histologic analysis) and level of alanine aminotransferase (ALT) were associated with liver stiffness.
- The chances of a patient having a level of stiffness that indicates cirrhosis increased with grade of inflammation and level of ALT.
- By using a conservative 14.5-kPa cutoff for the diagnosis of cirrhosis, grade 3 inflammation had an odds ratio of 9.10 (95% confidence interval, 2.49-33.4).
- Likewise, levels of ALT greater than 80 and 120 IU/L had odds ratios of 3.84 (95% confidence interval, 2.10-7.00) and 4.10 (95% confidence interval, 2.18-7.69), respectively.
- The effect of the level of ALT persisted when analysis was restricted to patients with fibrosis scores of F0 to F1.