Case Control Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Pharmacol Ther. Aug 8, 2020; 11(3): 40-47
Published online Aug 8, 2020. doi: 10.4292/wjgpt.v11.i3.40
Shared changes in angiogenic factors across gastrointestinal vascular conditions: A pilot study
Atiyekeogbebe R Douglas, Grainne Holleran, Sinead M Smith, Deirdre McNamara
Atiyekeogbebe R Douglas, Grainne Holleran, Sinead M Smith, Deirdre McNamara, TAGG Research Centre, School of Medicine, Trinity College Dublin, Dublin D24, Ireland
Author contributions: Douglas AR performed the experiments and wrote the manuscript; Holleran G participated in sample collection; Smith SM served as scientific advisor and was involved in analysis; McNamara D designed the study; corrected the manuscript and served as the guarantor.
Institutional review board statement: Full ethical approval was obtained from the Tallaght Hospital/St James’ Hospital Joint Research Ethics Committee.
Informed consent statement: Written informed consent was obtained from all patients prior to inclusion.
Conflict-of-interest statement: None of the authors had any conflicts of interest to declare.
Data sharing statement: No additional data.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Atiyekeogbebe R Douglas, MSc, Research Scientist, TAGG Research Centre, Trinity Centre, Tallaght Hospital, School of Medicine, Trinity College Dublin, College Green, Tallaght, Dublin D24, Ireland. douglaar@tcd.ie
Received: January 4, 2020
Peer-review started: January 14, 2020
First decision: April 8, 2020
Revised: May 11, 2020
Accepted: July 18, 2020
Article in press: July 18, 2020
Published online: August 8, 2020
ARTICLE HIGHLIGHTS
Research background

Neovascularisation is a common feature of gastrointestinal (GI) vascular disorders with differing aetiologies and presentations; including small bowel angiodysplasia (SBA), gastral antral vascular ectasia and portal hypertensive gastropathy. These lesions are all common causes of recurrent or chronic intestinal bleeding especially in adults above 60 years. GI vascular malformations and bleeding in SBA have been associated with varying disturbances in angiogenesis, however, the precise mechanisms underlying these conditions remain unclear. Our hypothesis is that response to a variety of upstream triggers including portal hypertension, hypoxia and inflammation, which may be regulated at a local level by common angiogenic regulators including Angiopoietin 1 (Ang-1), Ang-2 and vascular endothelial growth factor (VEGF) may be responsible for these conditions.

Research motivation

At present, the precise mechanisms underlying these conditions remain unclear and assessment of angiogenic factors across several GI vascular disorders associated with recurrent bleeding and anaemia has not been reported. In addition, there is currently no specific treatment for these vascular conditions, the development of which is limited by a deficient knowledge of the underlying pathophysiology.

Research objectives

The overarching aim of our work is to identify angiogenic factors associated with the condition which may be useful both as diagnostic and prognostic markers and as future treatment targets.

Research methods

Using enzyme-linked immunosorbent assay, concentrations of Ang-1, Ang-2 and VEGF were measured from 2 serum tubes of blood using standard phlebotomy techniques. Categorical data was compared with a Chi2 Test. Serum levels of angiogenic factors were expressed as a mean and compared between groups using the Student t-test. Results were controlled for patient demographics including age, gender and haemoglobin level. A P value of < 0.05 was considered significant.

Research results

We observed a common reduction in Ang-1 levels and elevation in Ang-2 levels across several GI vascular disorders compared to controls. Differences in Ang-1/Ang-2 ratios among vascular disorders compared to controls suggest disease-specific modulation. This warrants further investigation as potential biomarkers and therapeutic targets.

Research conclusions

Our novel pilot study shows the common alteration in Ang-1 and Ang-2 levels across a variety of GI disorders. This suggests that the modulation of these angiogenic factors may play a vital role in these GI vascular conditions. This shows the value of these factors as potential biomarkers and therapeutic targets.

Research perspectives

Targeting these angiogenic factors could potentially serve as diagnostic or prognostic biomarkers and therapeutic targets in a clinical setting.