Hepatitis B Surface Antigen Quantity Positively Correlates with Plasma Levels of microRNAs Differentially Expressed in Immunological Phases of Chronic Hepatitis B in Children

Abstract

Background and AimChildren with chronic hepatitis B (CHB) are at high risk of progressive liver disease. It is suggested that a newly-identified panel of 16 microRNAs is important in the pathogenesis of CHB in children. Subviral hepatitis B surface antigen (HBsAg) particles are produced in large excess over infectious virions. Interestingly, circulating HBsAg particles have been shown to carry microRNAs. A thorough characterisation of the identified microRNAs and HBsAg over time in plasma from children with CHB may provide useful information about the natural course of childhood CHB.Patients and MethodsA cohort of 42 children with CHB was followed over time. Three to five blood samples were obtained from each child at minimum intervals of half a year; in total 180 blood samples. Plasma levels of the 16 microRNAs previously identified were analysed by quantitative real-time polymerase-chain-reaction. Plasma HBsAg was quantified using ARCHITECT® HBsAg assay.ResultsThe presence of 14/16 plasma microRNAs in children with CHB was confirmed. All 14 microRNAs were significantly differentially expressed in different immunological phases of the disease. MicroRNA plasma levels were highest in immune-tolerant children, lower in immune-active children, and reached the lowest values in immune-inactive children, p<0.001. Plasma levels of four microRNAs decreased significantly over time in immune-tolerant and immune-active children whereas the microRNA plasma levels were stable in immune-inactive children, p<0.004. HBsAg quantity was positively correlated with plasma levels of 11/14 microRNAs, p<0.004.ConclusionThis is the first study to characterise plasma microRNAs and HBsAg over time in children with CHB. Our data suggest that plasma levels of selected microRNAs and HBsAg are inversely correlated with immunological control of CHB in children. Further studies are, however, needed to advance the understanding of microRNAs and HBsAg in the pathogenesis of CHB in children.

Function and Regulation of MicroRNAs and Their Potential as Biomarkers in Paediatric Liver Disease

“…Furthermore, this miRNA expression was correlated to the levels of circulatory HBsAg particles. These observations in adults are consistent with the one reported by Winther et al [148] comparing levels of plasma miRNAs in children with CHB considering HBsAg levels. Likewise, Ninomiya et al [179] reported upregulation of serum miR-100-5p, miR-125b-5p, miR-193b-3p, miR-194-3p, miR-30a-3p, miR-30c-2-3p, miR-3591-5p, miR-4709-3p, miR-574-3p and miR-99a-5p of CHB adult patients compared to healthy controls.…”

“…Thirty-two miRNAs were shown to be significantly differentially expressed between HBeAg+ and HBeAg− children. In addition to the 14 miRNAs described in the previous studies [147,148], nine upregulated and nine downregulated miRNAs were identified.…”

“…A follow up study (Table 3) [148] focused on the association of these 16 miRNAs with HBsAg over the course of CHB. Children were classified according to their immunological phase as immune-tolerant, immune-active and immune-inactive.…”

“…From the 16 miRNAs analysed, six were previously validated [147,148], the remaining were validated by qRT-PCR. Validation confirmed miR-28-5p, miR-30a-5p, miR-30e-3p, miR-378a-3p, miR-574-3p and let-7c to be upregulated and miR-654-3p to be downregulated in HBeAg+ compared to HBeAg− groups.…”

“…Likewise, Ninomiya et al [179] reported upregulation of serum miR-100-5p, miR-125b-5p, miR-193b-3p, miR-194-3p, miR-30a-3p, miR-30c-2-3p, miR-3591-5p, miR-4709-3p, miR-574-3p and miR-99a-5p of CHB adult patients compared to healthy controls. Overall, seven of these miRNAs including miR-99a, miR-100-5p, miR-194, miR-30a, miR-125b and miR-574, are consistently reported to be upregulated in CHB in both serum from adults [179] and plasma from children [147,148]. …”