Background and Aim: Bacterial infections are a well described
complication of cirrhosis and occur in 37% of hospitalized patients. Culture
positive infections in addition to the presence of bacterial products and
DNA lead to loss of liver function and decompensation in cirrhosis. The
mechanisms and molecular pathways associated with Bacterial
Translocation (BT) are unknown. The aims of this study were to determine:
i. macrophage phenotype and molecular pathways associated with
bacterial translocation ii. if intestinal macrophages in liver cirrhosis are
capable of modulating intestinal permeability.iii. structural integrity of the
epithelial barrier.
Methods: Duodenal biopsies and serum samples were collected from 29
patients with decompensated cirrhosis, 15 patients with compensated and
19 controls. Duodenal macrophages were characterized by means of flow
cytometry and IHC. Gene expression analysis was performed to determine
molecular pathways involved in BT. Inflammatory cytokine determination
was done in serum and culture supernatant by means of customized
cytometric bead arrays.
Results: Patients with decompensated cirrhosis demonstrated: increased
frequency of CD33+/CD14+/TREM-1+ and iNOS+ macrophages in their
duodenum, elevated mRNA levels of nitric oxide synthase 2 (NOS2),
chemokine ligand 2 (CCL2), chemokine ligand 13 (CCL13) and interleukin
8 (IL8) and increased serum levels of interleukin 6 (IL6), IL8 and
lipopolysaccharides (LPS). Additionally, patients with decompensated
cirrhosis showed an increase in NO, IL6, IL8 and CCL2 levels in culture
supernatant after short term duodenal biopsy culture. Although the
epithelial barrier on EM seemed intact, significantly increased expression of
the “pore” forming tight junction claudin 2 was observed.
Conclusion: This study showed the presence of activated CD14+Trem-
1+iNOS+ intestinal macrophages and increased levels of NO, IL-6 and
claudin-2 levels in the duodenum of patients with decompensated liver
cirrhosis, suggesting that these factors enhance intestinal permeability to
bacterial products. / Afrikaans: Inleiding: Bakteriele infeksie is ‘n beskryfde komplikasie van lewersirrose
wat in 37% van gehospitaliseerde pasiente voorkom. Kultuur positiewe
infeksies asook die teenwoordigheid van bakteriele produkte en DNA lei tot
verlies van lewerfunksie en dekompensasie. Die molekulere meganismes
wat verband hou met bakteriele translokasie is nog onbekend. Die doel van
hierdie studie was om: i. Makrofaag fenotipe en molekulere meganismes
geassosieerd met bakteriele translokasie te beskryf, ii. te bepaal of
intestinale makrofage dermdeurlaatbaarheid beinvloed, asook iii. om die
struktruele integriteit van die dermwand te bepaal.
Methods: Serum en dunderm biopsies was verkry van 29 pasiente met
gedekompenseerde lewer sirrose, 15 pasiente met gekompenseerde
sirrose en 19 kontroles. Dunderm makrofage was gekarakteriseer met
behulp van vloeisitometrie en immunohistochemie. Molekulere meganisms
belangrik tydens bakteriele translokasie was bepaal met behulp van geneekspressie.
Serum en selkultuur supernatant sitokien bepalings was met
Bioplex assays gedoen.
Resultate: Pasiente met gedekompenseerde sirrose demonstreer: ‘n
verhoogde frekwensie van CD33+/CD14+/TREM-1+ en iNOS+ makrofage
in hul dunderm, verhoogde mRNA vlakke van NOS2, CCL2, CCL13 en IL8
asook verhoogde serum vlakke van IL6, IL8, LPS. Addisioneel het pasiente
met gedekompenseerde sirrose vehoogde supernatant vlakke van NO, IL6,
IL8 and CCL2 na kort termyn dunderm biopsie kulture. Alhoewel
elekronmikroskopie gewys het dat die dundermwand intak is, was daar
statisties-beduidend verhoogde ekspressie van die “porie” vormende vasteaansluitings-
proteien, claudin 2 sigbaar. Gevolgtrekking: Gesamentlik het die studie gewys dat geaktiveerde
CD14+/Trem-1+/iNOS+ intestinale makrofage asook verhoogde vlakke van
NO, IL-6 en claudin-2 teenwoordig is in die dunderm van pasiente met
gedekompenseerde sirrose. Dit dui daarop dat diè faktore derm
deurlaatbaarheid vir bakteriele produkte kan verhoog. / Dissertation (MSc)--University of Pretoria, 2011. / Immunology / MSc / Unrestricted
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:up/oai:repository.up.ac.za:2263/31134 |
| Date | 08 August 2012 |
| Creators | Du Plessis, Johannie |
| Contributors | Van der Merwe, Schalk Willem |
| Publisher | University of Pretoria |
| Source Sets | South African National ETD Portal |
| Detected Language | Unknown |
| Type | Dissertation |
| Rights | © 2011, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. E13/4/238/ |
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