Identification of Helicobacter pylori and Other Helicobacter Species by PCR, Hybridization, and Partial DNA Sequencing in Human Liver Samples from Patients with Primary Sclerosing Cholangitis or Primary Biliary Cirrhosis

Abstract

Helicobacter pylori was identified in human liver tissue by PCR, hybridization, and partial DNA sequencing. Liver biopsies were obtained from patients with primary sclerosing cholangitis (n = 12), primary biliary cirrhosis (n = 12), and noncholestatic liver cirrhosis (n = 13) and (as controls) normal livers (n = 10). PCR analyses were carried out using primers for the Helicobacter genus, Helicobacter pylori(the gene encoding a species-specific 26-kDa protein and the 16S rRNA),Helicobacter bilis, Helicobacter pullorum, andHelicobacter hepaticus. Samples from patients with primary biliary cirrhosis and primary sclerosing cholangitis (11 and 9 samples, respectively) were positive by PCR with Helicobactergenus-specific primers. Of these 20 samples, 8 were positive with the 16S rRNA primer and 9 were positive with the 26-kDa protein primer ofH. pylori. These nine latter samples were also positive by Southern blot hybridization for the amplified 26-kDa fragment, and four of those were verified to be H. pylori by partial 16S rDNA sequencing. None of the samples reacted with primers for H. bilis, H. pullorum, or H. hepaticus. None of the normal livers had positive results in theHelicobacter genus PCR assay, and only one patient in the noncholestatic liver cirrhosis group, a young boy who at reexamination showed histological features suggesting primary sclerosing cholangitis, had a positive result in the same assay. Helicobacterpositivity was thus significantly more common in patients with cholestatic diseases (20 of 24) than in patients with noncholestatic diseases and normal controls (1 of 23) (P = <0.00001). Patients positive for Helicobacter genus had significantly higher values of alkaline phosphatases and prothrombin complex than Helicobacter-negative patients (P = 0.0001 and P = 0.0003, respectively). Among primary sclerosing cholangitis patients,Helicobacter genus PCR positivity was weakly associated with ulcerative colitis (P = 0.05). Significant differences related to blood group or HLA status were not found.

Escherichia coliinfection induces autoimmune cholangitis and anti-mitochondrial antibodies in non-obese diabetic (NOD).B6 (Idd10/Idd18) mice

“…Clues indicating a microbial aetiological component to the pathogenesis of PBC were based largely on experimental evidence of B and T cell cross-reactivity between the major mitochondrial autoantigens and their mimicking microbial antigenic epitopes [27,29,[43][44][45][46][47][48][49][50]. Additional support comes from epidemiological studies, case reports or molecular evidence of the presence of microbial or viral agents in the liver or bile specimens of patients with PBC [13,29,[50][51][52]. Several hypothetical mechanisms, such as bystander activation of autoreactive cells, induction of proinflammatory cytokines by microbial antigens and molecular mimicry between the microorganism and the host have been proposed to explain how microbes initiate autoimmunity [9][10][11][12].…”

Bacterial motif DNA as an adjuvant for the breakdown of immune self-tolerance to pyruvate dehydrogenase complex

“…10 This combination of factors could occur in humans if bacterial infection (contributing both the inflammatory environment and foreign PDC) occurred in the biliary tree in the context of the aberrant biliary epithelial cell surface expression of self-PDC shown to be present in PBC 11 and to predate any other features of the disease. 12 Evidence in support of this model comes from studies showing a significantly increased prevalence of mucosal bacterial infection in PBC 13 and data suggesting that autoreactive responses in this disease are targeted to the mucosal surfaces. 14,15 In the current study, we used murine modeling to address a further hypothetical role for bacteria in the development of harmful autoreactivity to PDC, that of skewing the resultant autoreactive response toward the tissue-harmful phenotype reported in PBC.…”

Requirement for TNF-Tnfrsf1 signalling for sclerosing cholangitis in mice chronically infected byCryptosporidium parvum

“…The sclerosing cholangitis that occurs in boys with mutations in their Tnfsf5 gene is important because it may result in liver failure and require transplant treatment. Cryptosporidium parvum has been implicated in some affected boys, although chronic infection of the biliary tree by other pathogens, possibly including Helicobacter species [14], might also contribute. Sclerosing cholangitis can be reproduced in mice with a disrupted Tnfsf5 gene by infection with CP, provided that the infection persists for 6 weeks or longer [2].…”