Diagnostic Efficacy of Serological Antibody Detection Tests for Hepatitis Delta Virus: A Systematic Review and Meta-Analysis

Background and Aims Coinfection of hepatitis delta virus (HDV) with hepatitis B virus (HBV) causes the most severe form of viral hepatitis, and the global prevalence of HDV infection is underestimated. Although serological testing of anti-HDV antibodies is widely used in the diagnosis of HDV, its diagnostic efficacy remains unclear. This study aimed to evaluate the diagnostic efficacy of HDV serological tests, the results of which may assist in the diagnosis of HDV. Methods Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed. The PubMed, Web of Science and Cochrane Library databases were searched from the beginning to 31 May 2023. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. STATA SE was used for the meta-analysis of the sensitivity, specificity, positive likelihood ratio and negative likelihood ratio. Results Among a total of 1376 initially identified studies, only 12 articles met the final inclusion criteria. The pooled sensitivity and specificity were 1.00 (95% CI: 0.00-1.00) and 0.71 (95% CI: 0.50-0.78) for HDV total antibodies, 0.96 (95% CI: 0.83-0.99) and 0.98 (95% CI: 0.82-1.00) for anti-HDV IgM and 0.95 (95% CI: 0.86-0.98) and 0.96 (95% CI: 0.67-1.00) for anti-HDV IgG. The pooled sensitivity and specificity for HDV serological tests were 0.99 (95% CI: 0.96-1.00) and 0.90 (95% CI: 0.79-0.96). Conclusions This meta-analysis suggests that serological tests have high diagnostic performance in detecting antibodies against HDV, especially in HDV IgM and IgG. However, this conclusion is based on studies of a limited number and quality, and the development of new diagnostic tools with higher precision and reliability is still necessary.

TGFβ1-RCN3-TGFBR1 loop facilitates pulmonary fibrosis by orchestrating fibroblast activation

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) bears high mortality due to unclear pathogenesis and limited therapeutic options. Therefore, identifying novel regulators is required to develop alternative therapeutic strategies.

METHODS

The lung fibroblasts from IPF patients and Reticulocalbin 3 (RCN3) fibroblast-selective knockdown mouse model were used to determine the importance of Rcn3 in IPF; the epigenetic analysis and protein interaction assays, including BioID, were used for mechanistic studies.

RESULTS

Reticulocalbin 3 (RCN3) upregulation is associated with the fibrotic activation of lung fibroblasts from IPF patients and Rcn3 overexpression blunts the antifibrotic effects of pirfenidone and nintedanib. Moreover, repressing Rcn3 expression in mouse fibroblasts ameliorates bleomycin-induced lung fibrosis and pulmonary dysfunction in vivo. Mechanistically, RCN3 promotes fibroblast activation by maintaining persistent activation of TGFβ1 signalling via the TGFβ1-RCN3-TGFBR1 positive feedback loop, in which RCN3 upregulated by TGFβ1 exposure detains EZH2 (an epigenetic methyltransferase) in the cytoplasm through RCN3-EZH2 interaction, leading to the release of the EZH2-H3K27me3 epigenetic repression of TGFBR1 and the persistent expression of TGFBR1.

CONCLUSIONS

These findings introduce a novel regulating mechanism of TGFβ1 signalling in fibroblasts and uncover a critical role of the RCN3-mediated loop in lung fibrosis. RCN3 upregulation may cause resistance to IPF treatment and targeting RCN3 could be a novel approach to ameliorate pulmonary fibrosis.

PNPLA3-I148M Variant Promotes the Progression of Liver Fibrosis by Inducing Mitochondrial Dysfunction

Patatin-like phospholipase domain-containing 3 (PNPLA3) rs738409 polymorphism (I148M) is strongly associated with non-alcoholic steatohepatitis and advanced fibrosis; however, the underlying mechanisms remain largely unknown. In this study, we investigated the effect of PNPLA3-I148M on the activation of hepatic stellate cell line LX-2 and the progression of liver fibrosis. Immunofluorescence staining and enzyme-linked immunosorbent assay were used to detect lipid accumulation. The expression levels of fibrosis, cholesterol metabolism, and mitochondria-related markers were measured via real-time PCR or western blotting. Electron microscopy was applied to analyze the ultrastructure of the mitochondria. Mitochondrial respiration was measured by a Seahorse XFe96 analyzer. PNPLA3-I148M significantly promoted intracellular free cholesterol aggregation in LX-2 cells by decreasing cholesterol efflux protein (ABCG1) expression; it subsequently induced mitochondrial dysfunction characterized by attenuated ATP production and mitochondrial membrane potential, elevated ROS levels, caused mitochondrial structural damage, altered the oxygen consumption rate, and decreased the expression of mitochondrial-function-related proteins. Our results demonstrated for the first time that PNPLA3-I148M causes mitochondrial dysfunction of LX-2 cells through the accumulation of free cholesterol, thereby promoting the activation of LX-2 cells and the development of liver fibrosis.

Bevacizumab is an Efficient Therapeutic Approach with Low Side Effects in Patient-Derived Xenografts of Adenoid Cystic Carcinoma of the Lacrimal Gland

Purpose

Adenoid cystic carcinoma (ACC) of the lacrimal gland (LGACC) is an aggressive malignant lacrimal gland tumor with a generally poor prognosis. Survival rates for LGACC are 56% at 5 years and 49% at 10 years. Recent studies have indicated that anti-vascular endothelial growth factor (VEGF) therapy can inhibit angiogenesis in ACC cells. This study was designed to explore the efficacy of the antiangiogenic drug bevacizumab in a LGACC patient-derived xenograft (PDX) animal model.

Methods

The histological structure of PDX was determined by hematoxylin-eosin staining to confirm successful xenografting. Immunohistochemistry (IHC) was used to detect the expression of neovascularization-related genes in LGACC patients and in the PDX model, including VEGF, VEGFR1, and FGFR. In order to compare the efficacy of antiangiogenic drug and traditional chemotherapy drug, PDX models were treated with bevacizumab and cisplatin respectively, and body weight was evaluated. Subsequently, the neovascularization-related proteins VEGF, VEGFR2, and CD34, tumor suppressor P53 and proliferation-related protein Ki67 were analyzed by IHC. Quantitative real-time PCR was employed to examine the mRNA expression of apoptosis-related genes BAD and Caspase 9, and of HIF1α.

Results

VEGF, VEGFR1, and FGFR were highly expressed in patients with LGACC and PDX models. Both bevacizumab and cisplatin treatment inhibited PDX tumor growth. The body weight of PDX models treated with cisplatin significantly decreased from day 15, while those treated with bevacizumab did not markedly change. Bevacizumab reduced the expression of VEGF, CD34, and Ki67 in PDX tumors; whereas, bevacizumab upregulated P53 and downregulated HIF1α levels.

Conclusion

The present study indicates that antiangiogenic drugs may be a promising treatment strategy for LGACC.

ASPP2 Inhibits the Profibrotic Effects of Transforming Growth Factor-β1 in Hepatic Stellate Cells by Reducing Autophagy

BACKGROUND

Apoptosis-stimulating protein of p53-2 (ASPP2) is a damage-inducible P53-binding protein that enhances damage-induced apoptosis. Fibrosis is a wound-healing response, and hepatic stellate cells (HSCs) are key players in liver fibrogenesis. However, little is known about the relationship between ASPP2 and hepatic fibrosis.

AIMS

We investigated the effects of ASPP2 overexpression in HSCs and the role of ASPP2 in mouse liver fibrogenesis.

METHODS

Human HSCs (LX-2 cells) were pre-incubated with GFP adenovirus (Ad) or ASPP2 adenovirus (AdASPP2) for 24 h and then treated with or without TGF-β1. ASPP2^+/- and ASPP2+/+ Balb/c mice were used to examine the effects of ASPP2 on liver fibrosis in vivo. ASPP2+/+ Balb/c mice were generated by injecting AdASPP2 into the tail vein of ASPP2 WT Balb/c mice; all mice received intraperitoneal injections of carbon tetrachloride.

RESULTS

In this study, ASPP2 was found to markedly inhibit TGF-β1-induced fibrogenic activation of LX-2 cells. Further experiments using an autophagic flux assay confirmed that ASPP2 reduced the fibrogenic activation of LX-2 cells by inhibiting autophagy. Moreover, we found that ASPP2 overexpression attenuated the anti-apoptotic effects of TGF-β1 in LX-2 cells. The extent of liver fibrosis was markedly reduced in ASPP2+/+ mouse liver tissue compared with control mice; however, in ASPP2^+/- mice, hepatic collagen deposition was significantly increased.

CONCLUSION

These results suggest that TGF-β1-induced autophagy is required for the fibrogenic response in LX-2 cells and that ASPP2 may both inhibit TGF-β1-induced autophagy and decrease liver fibrosis.