Circulatory microRNA-142 as potential biomarker of disease progression in paediatric cystic fibrosis-associated liver disease

Abstract

Background and Aims: Despite the increased life span of cystic fibrosis (CF) patients during the past decade, cystic fibrosisassociated liver disease (CFLD) is still one of the leading causes of morbidity and mortality in children with CF. Liver biopsy, an invasive procedure, remains the gold standard to assess the severity of liver damage in CFLD prior to the advent of cirrhosis and portal hypertension despite concerns over sampling limitations. We investigated circulatory microRNAs (miRNAs) as non-invasive biomarkers to diagnose and assess progression of paediatric CFLD. Methods: A total of 90 children were allocated into three study cohorts based on clinical, biochemical and imaging assessment as follows: healthy controls (Controls, n = 30), CF patients with no evidence of liver disease (CFnoLD, n = 30) and CFLD (n = 30; subdivided according to liver biopsy fibrosis stages: F0, F1-2 and F3-4 n = 10 each). miRNAs were analysed in serum using the Ion Proton sequencer with ten samples pooled into each one of the three libraries per group. Significant differentially expressed miRNAs were detected using normalized read counts and pair-wise comparisons. Selected miRNAs were further validated by qRT-PCR and analysed using ANOVA (p < 0.05). Spearman correlationwas used to determine the relation between miRNAs and fibrosis stages. Results: We identified miR-122-5p (p = 0.019), miR-144-3p (p = 0.031), miR-18a-5p (p = 0.031) and miR-142-3p (p = 0.039) to be differentially expressed between the groups. Post-hoc analysis showed a 2.5 fold increase of miR-122-5p in CFLD patients compared to CFnoLD (p = 0.042). In CFLD, negative correlations were observed between miR-122-5p (rs = -0.367, p = 0.048), miR-365-3p (rs = -0.39, p = 0.033), miR-199a-3p (rs = -0.4, p = 0.028) and miR-20a-5p (rs = -0.545, p = 0.002), and hepatic fibrosis stage. Interestingly, miR-142-3p showed a highly significant positive correlation with increasing fibrosis severity (rs = 0.636, p = 0.0002). Post-hoc analysis revealed a significant increase in serum miR-365a-3p and miR-199a- 3p in F0 vs. F1-F4, suggesting potential utility as markers of early fibrogenesis. In contrast, miR-142-3pwas significantly elevated in F3- 4 compared to F0- F2, suggesting its use as a marker of severe fibrosis/ cirrhosis in CF. Conclusions: Our study has identified several serum miRNAs with potential to diagnose liver disease, detect fibrogenesis and monitor fibrosis progression in children with CF. Diagnostic panels using combinations of these miRNAs require validation in larger cohorts.L6212234342018-03-19 <br />