Defective monocyte oxidative burst predicts infection in alcoholic hepatitis and is associated with reduced expression of NADPH oxidase
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Objective In order to explain the increased
susceptibility to serious infection in alcoholic hepatitis,
we evaluated monocyte phagocytosis, aberrations of
associated signalling pathways and their reversibility, and
whether phagocytic defects could predict subsequent
infection.
Design Monocytes were identified from blood samples
of 42 patients with severe alcoholic hepatitis using
monoclonal antibody to CD14. Phagocytosis and
monocyte oxidative burst (MOB) were measured ex vivo
using flow cytometry, luminometry and bacterial killing
assays. Defects were related to the subsequent
development of infection. Intracellular signalling
pathways were investigated using western blotting and
PCR. Interferon-γ (IFN-γ) was evaluated for its
therapeutic potential in reversing phagocytic defects.
Paired longitudinal samples were used to evaluate the
effect of in vivo prednisolone therapy.
Results MOB, production of superoxide and bacterial
killing in response to Escherichia coli were markedly
impaired in patients with alcoholic hepatitis.
Pretreatment MOB predicted development of infection
within two weeks with sensitivity and specificity that
were superior to available clinical markers. Accordingly,
defective MOB was associated with death at 28 and
90 days. Expression of the gp91phox subunit of
nicotinamide adenine dinucleotide phosphate (NADPH)
oxidase was reduced in patients with alcoholic hepatitis
demonstrating defective MOB. Monocytes were refractory
to IFN-γ stimulation and showed high levels of a
negative regulator of cytokine signalling, suppressor of
cytokine signalling-1. MOB was unaffected by 7 days in
vivo prednisolone therapy.
Conclusions Monocyte oxidative burst and bacterial
killing is impaired in alcoholic hepatitis while bacterial
uptake by phagocytosis is preserved. Defective MOB is
associated with reduced expression of NADPH oxidase in
these patients and predicts the development of infection
and death.
susceptibility to serious infection in alcoholic hepatitis,
we evaluated monocyte phagocytosis, aberrations of
associated signalling pathways and their reversibility, and
whether phagocytic defects could predict subsequent
infection.
Design Monocytes were identified from blood samples
of 42 patients with severe alcoholic hepatitis using
monoclonal antibody to CD14. Phagocytosis and
monocyte oxidative burst (MOB) were measured ex vivo
using flow cytometry, luminometry and bacterial killing
assays. Defects were related to the subsequent
development of infection. Intracellular signalling
pathways were investigated using western blotting and
PCR. Interferon-γ (IFN-γ) was evaluated for its
therapeutic potential in reversing phagocytic defects.
Paired longitudinal samples were used to evaluate the
effect of in vivo prednisolone therapy.
Results MOB, production of superoxide and bacterial
killing in response to Escherichia coli were markedly
impaired in patients with alcoholic hepatitis.
Pretreatment MOB predicted development of infection
within two weeks with sensitivity and specificity that
were superior to available clinical markers. Accordingly,
defective MOB was associated with death at 28 and
90 days. Expression of the gp91phox subunit of
nicotinamide adenine dinucleotide phosphate (NADPH)
oxidase was reduced in patients with alcoholic hepatitis
demonstrating defective MOB. Monocytes were refractory
to IFN-γ stimulation and showed high levels of a
negative regulator of cytokine signalling, suppressor of
cytokine signalling-1. MOB was unaffected by 7 days in
vivo prednisolone therapy.
Conclusions Monocyte oxidative burst and bacterial
killing is impaired in alcoholic hepatitis while bacterial
uptake by phagocytosis is preserved. Defective MOB is
associated with reduced expression of NADPH oxidase in
these patients and predicts the development of infection
and death.
Date Issued
2016-02-09
Date Acceptance
2015-10-25
Citation
Gut, 2016, 66 (3), pp.519-529
ISSN
1468-3288
Publisher
BMJ Publishing Group
Start Page
519
End Page
529
Journal / Book Title
Gut
Volume
66
Issue
3
Copyright Statement
© 2016 The Authors. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/ licenses/by/4.0/
License URL
Sponsor
Rosetrees Trust
National Institute for Health Research
Medical Research Council (MRC)
Medical Research Council (MRC)
Identifier
https://gut.bmj.com/content/66/3/519
Grant Number
JS16/M115-F1
08/14/44
MR/K010514/1
MR/M003132/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Gastroenterology & Hepatology
CYTOKINE SIGNALING SOCS
ACUTE LIVER-FAILURE
INTERFERON-GAMMA
PULMONARY TUBERCULOSIS
VIRUS-INFECTION
UNITED-STATES
MACROPHAGES
CIRRHOSIS
DISEASE
SUPPRESSORS
ALCOHOLIC LIVER DISEASE
BACTERIAL INFECTION
IMMUNOLOGY IN HEPATOLOGY
Adult
Anti-Inflammatory Agents
Bacterial Infections
Case-Control Studies
Cells, Cultured
Coculture Techniques
Colony Count, Microbial
Escherichia coli
Female
Hepatitis, Alcoholic
Humans
Interferon-gamma
Male
Membrane Glycoproteins
Middle Aged
Monocytes
NADPH Oxidase 2
NADPH Oxidases
Phagocytosis
Predictive Value of Tests
Prednisolone
Respiratory Burst
Signal Transduction
Suppressor of Cytokine Signaling 1 Protein
Monocytes
Cells, Cultured
Humans
Escherichia coli
Bacterial Infections
Hepatitis, Alcoholic
Prednisolone
Membrane Glycoproteins
Anti-Inflammatory Agents
Coculture Techniques
Colony Count, Microbial
Case-Control Studies
Predictive Value of Tests
Signal Transduction
Respiratory Burst
Phagocytosis
Adult
Middle Aged
Female
Male
Interferon-gamma
Suppressor of Cytokine Signaling 1 Protein
NADPH Oxidase 2
NADPH Oxidases
Gastroenterology & Hepatology
1103 Clinical Sciences
1114 Paediatrics and Reproductive Medicine
Publication Status
Published
Date Publish Online
2016-02-09