False positive anti-hepatitis A virus immunoglobulin M in autoimmune hepatitis/primary biliary cholangitis overlap syndrome: A case report.

BACKGROUND: Autoimmune hepatitis (AIH) is an immune-mediated liver disease affecting all age groups. Associations between hepatitis A virus (HAV) and AIH have been described for many years. Herein, we report a case of an AIH/primary biliary cholangitis (PBC) overlap syndrome with anti-HAV immunoglobulin M (IgM) false positivity. CASE SUMMARY: A 55-year-old man was admitted with manifestations of anorexia and jaundice along with weakness. He had marked transaminitis and hyperbilirubinemia. Viral serology was positive for HAV IgM and negative for others. Autoantibody screening was positive for anti-mitochondria antibody but negative for others. Abdominal ultrasound imaging was normal. He was diagnosed with acute hepatitis A. After symptomatic treatment, liver function tests gradually recovered. Several months later, his anti-HAV IgM positivity persisted and transaminase and bilirubin levels were also more than 10 times above of the upper limit of normal. Liver histology was prominent, and HAV RNA was negative. Therefore, AIH/primary biliary cholangitis (PBC) overlap syndrome diagnosis was made based on the "Paris Criteria". The patient was successfully treated by immunosuppression. CONCLUSION: This case highlights that autoimmune diseases or chronic or acute infections, may cause a false-positive anti-HAV IgM result because of cross-reacting antibodies. Therefore, the detection of IgM should not be the only method for the diagnosis of acute HAV infection. HAV nucleic acid amplification tests should be employed to confirm the diagnosis.

Identification of key genes in non­alcoholic fatty liver disease progression based on bioinformatics analysis.

Due to economic development and lifestyle changes, the incidence of non­alcoholic fatty liver disease (NAFLD) has gradually increased in recent years. However, the pathogenesis of NAFLD is not yet fully understood. To identify candidate genes that contribute to the development and progression of NAFLD, two microarray datasets were downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) were identified and functional enrichment analyses were performed. A protein­protein interaction network was constructed and modules were extracted using the Search Tool for the Retrieval of Interacting Genes and Cytoscape. The enriched functions and pathways of the DEGs included 'cellular macromolecule biosynthetic process', 'cellular response to chemical stimulus', 'extracellular matrix organization', 'metabolic pathways', 'insulin resistance' and 'forkhead box protein O1 signaling pathway'. The DEGs, including type­1 angiotensin II receptor, formin­binding protein 1­like, RNA­binding protein with serine­rich domain 1, Ras­related C3 botulinum toxin substrate 1 and polyubiquitin­C, were identified using multiple bioinformatics methods and validated in vitro with reverse transcription­quantitative polymerase chain reaction analysis. In conclusion, five hub genes were identified in the present study, and they may aid in understanding of the molecular mechanisms underlying the development and progression of NAFLD.