Integrated GWAS and mRNA Microarray Analysis Identified IFNG and CD40L as the Central Upstream Regulators in Primary Biliary Cholangitis.

Genome-wide association studies (GWASs) in European and East Asian populations have identified more than 40 disease-susceptibility genes in primary biliary cholangitis (PBC). The aim of this study is to computationally identify disease pathways, upstream regulators, and therapeutic targets in PBC through integrated GWAS and messenger RNA (mRNA) microarray analysis. Disease pathways and upstream regulators were analyzed with ingenuity pathway analysis in data set 1 for GWASs (1,920 patients with PBC and 1,770 controls), which included 261 annotated genes derived from 6,760 single-nucleotide polymorphisms (P < 0.00001), and data set 2 for mRNA microarray analysis of liver biopsy specimens (36 patients with PBC and 5 normal controls), which included 1,574 genes with fold change >2 versus controls (P < 0.05). Hierarchical cluster analysis and categorization of cell type-specific genes were performed for data set 2. There were 27 genes, 10 pathways, and 149 upstream regulators that overlapped between data sets 1 and 2. All 10 pathways were immune-related. The most significant common upstream regulators associated with PBC disease susceptibility identified were interferon-gamma (IFNG) and CD40 ligand (CD40L). Hierarchical cluster analysis of data set 2 revealed two distinct groups of patients with PBC by disease activity. The most significant upstream regulators associated with disease activity were IFNG and CD40L. Several molecules expressed in B cells, T cells, Kupffer cells, and natural killer-like cells were identified as potential therapeutic targets in PBC with reference to a recently reported list of cell type-specific gene expression in the liver. Conclusion: Our integrated analysis using GWAS and mRNA microarray data sets predicted that IFNG and CD40L are the central upstream regulators in both disease susceptibility and activity of PBC and identified potential downstream therapeutic targets.

Selection of regimens for patients with hepatitis C virus genotype/serotype discrepancy.

In the present study, the usefulness of the resistance-associated variant (RAV) analysis to select direct acting antiviral (DAA) drugs for patients with hepatitis C virus (HCV) genotype/serotype discrepancy was evaluated. The core-genotype and serotype were determined in the 559 patients recruited in the study. The RAV analysis and NS5B-genotype determination were performed in the eight patients who exhibited a genotype/serotype discrepancy. One of these patients exhibited a core-genotype 1b/serotype 2, and detection by RAV analysis was possible in this patient. The other seven patients demonstrated a core-genotype 2/serotype 1, and detection using the RAV analysis was possible in four of them. The NS5B-genotype was 1b in all patients in whom detection using the RAV analysis was possible and was other than 1b in patients in whom detection using the RAV analysis was impossible. The RAV analysis could detect RNA sequences specific to genotype 1b in the NS5A region. Therefore, in patients with genotype/serotype discrepancy in whom detection using the RAV analysis is possible, the treatment regimens should be selected based on the assumption that HCV with genome that is highly homologous to genotype 1b is present in the NS5A region.

Case of autoimmune hepatitis with markedly enlarged hepatoduodenal ligament lymph nodes.

Autoimmune hepatitis (AIH) is a necroinflammatory liver disease of unknown etiology. The disease is characterized histologically by interface hepatitis, biochemically by increased aspartate aminotransferase and alanine aminotransferase levels, and serologically by increased autoantibodies and immunoglobulin G levels. Here we discuss AIH in a previously healthy 37-year-old male with highly elevated serum levels of soluble interleukin-2 receptor and markedly enlarged hepatoduodenal ligament lymph nodes (HLLNs, diameter, 50 mm). Based on these observations, the differential diagnoses were AIH, lymphoma, or Castleman's disease. Liver biopsy revealed the features of interface hepatitis without bridging fibrosis along with plasma cell infiltration which is the typical characteristics of acute AIH. Lymph node biopsy revealed lymphoid follicles with inflammatory lymphocytic infiltration; immunohistochemical examination excluded the presence of lymphoma cells. Thereafter, he was administered corticosteroid therapy: after 2 mo, the enlarged liver reached an almost normal size and the enlarged HLLNs reduced in size. We could not find AIH cases with such enlarged lymph nodes (diameter, 50 mm) in our literature review. Hence, we speculate that markedly enlarged lymph nodes observed in our patient may be caused by a highly activated, humoral immune response in AIH.