Correlation of cell-free DNA plasma concentration with severity of non-alcoholic fatty liver disease

2017 Journal of translational medicine 15;1 (106)

BACKGROUND: The assessment of fibrosis and inflammatory activity is essential to identify patients with non-alcoholic fatty liver disease (NAFLD) at risk for progressive disease. Serum markers and ultrasound-based methods can replace liver biopsy for fibrosis staging, whereas non-invasive characterization of inflammatory activity remains a clinical challenge. Cell-free DNA (cfDNA) is a novel non-invasive biomarker for assessing cellular inflammation and cell death, which has not been evaluated in NAFLD. METHODS: Patients and healthy controls from two previous studies were included. NAFLD disease activity and severity were non-invasively characterized by liver stiffness measurement (transient elastography, TE) including steatosis assessment with controlled attenuation parameter (CAP), single-proton magnetic resonance spectroscopy (1H-MRS) for determination of hepatic fat fraction, aminotransferases and serum ferritin. cfDNA levels (90 and 222 bp fragments) were analyzed using quantitative real-time PCR. RESULTS: Fifty-eight NAFLD patients (age 62 +/- 11 years, BMI 28.2 +/- 3.5 kg/m2) and 13 healthy controls (age 38 +/- 12 years, BMI 22.4 +/- 2.1 kg/m2) were included. 90 bp cfDNA levels were significantly higher in NAFLD patients compared to healthy controls: 3.7 (1.3-23.1) vs. 2.9 (1.4-4.1) ng/mL (p = 0.014). In the NAFLD cohort, circulating cfDNA correlated significantly with disease activity and severity, especially in patients with elevated liver stiffness (n = 13, 22%) compared to cases with TE values =7 kPa: cf90 bp 6.05 (2.41-23.13) vs. 3.16 (1.29-7.31) ng/mL (p