Protease Activated Receptor-2 and Gastrointestinal Dysfunction in Critical Illness

April 14, 2026 updated by: Enid Martinez, Boston Children's Hospital

Examining the Role of Protease-activated Receptor 2 Agonists in Gastrointestinal Dysfunction in Pediatric Surgical Critical Illness

Gastrointestinal (GI) dysfunction affects up to 50% of medical and surgical critically ill children. GI dysfunction, specifically gastric dysmotility and loss of epithelial barrier integrity, is associated with significant morbidity in critical illness. The mechanisms underlying GI dysfunction in critical illness are not well understood. GI dysfunction in surgery and critical illness has been associated with inflammation. There is evidence to suggest the protease-activated receptor 2 (PAR2) is a link between inflammation and GI dysfunction. PAR2 is a G-coupled receptor present throughout the GI tract. PAR2 mediates GI motility and epithelial barrier integrity. PAR2 is activated by PAR2 agonists, specifically GI serine proteases and zonulin, released under conditions of inflammation. In this study the investigators will examine the relationship between inflammation and PAR2 activation by PAR2 agonists and subsequent GI dysfunction in pediatric critically ill surgical patients. The overall hypothesis of this study is that PAR2 activation by PAR2 agonists, GI serine proteases and zonulin, released due to inflammation results in gastric dysmotility and loss of epithelial barrier integrity. In this study, the investigators will examine whether PAR2 agonist expression is increased and correlates with GI dysfunction in critically ill surgical pediatric patients. This proposal fills a knowledge gap in the understanding of mechanisms for GI dysfunction in critical illness, and will be applicable to all surgical and medical critically ill children.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

The investigators in this study aim to examine a plausible mechanism by which gastrointestinal dysfunction, gastric dysmotility and loss of epithelial barrier integrity, occur in critical illness. Specifically, the investigators will examine whether an increase in PAR2 agonist levels, zonulin and serine proteases, are associated with gastric dysmotility and loss of epithelial barrier integrity in critical surgical illness in children. The investigators will examine GI function, gastric motility and epithelial barrier integrity, and PAR2 agonist levels, zonulin and serine protease, in participants before surgery and after surgery. Specifically, children undergoing posterior spinal fusion, a known significant inflammatory trigger, and with planned admissions to the intensive care unit will be enrolled. Gastrointestinal function and PAR2 agonist levels will be tested non-invasively in blood and stool.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
99

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Massachusetts
      • Boston, Massachusetts, United States, 02115
        • Boston Children's Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

2 years to 30 years (Child, Adult)

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Children undergoing posterior spinal fusion and admitted to the pediatric intensive care unit

Description

Inclusion Criteria:

  • 2 years and older

Exclusion Criteria:

  • Liver dysfunction
  • Renal dysfunction
  • Pre-diagnosed gastroparesis/ delayed gastric emptying
  • Pre-diagnosed gastrointestinal malabsorption
  • Contraindication to acetaminophen administration

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
PAR2 agonist activity- serum zonulin
Time Frame: Immediately pre-operative versus post-operative day 1
PAR2 agonist activity will be measured by serum zonulin levels (ng/mL)
Immediately pre-operative versus post-operative day 1
PAR2 agonist activity- fecal protease activity
Time Frame: Immediately pre-operative versus post-operative day 1
PAR2 agonist activity will be measured by fecal serine protease activity (trypsin units/gm protein)
Immediately pre-operative versus post-operative day 1

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Gastric motility by the acetaminophen absorption test- AUC
Time Frame: Immediately pre-operative versus post-operative day 1
Pharmacokinetic parameters of acetaminophen will be used to determined gastric motility including the concentration of acetaminophen at 60 minutes (mcg/mL).
Immediately pre-operative versus post-operative day 1
Epithelial barrier integrity by serum biomarkers
Time Frame: Immediately pre-operative versus post-operative day 1
Epithelial barrier integrity by serum biomarkers, specifically serum zonulin (ng/mL) and lipopolysaccharide binding protein levels (ng/mL).
Immediately pre-operative versus post-operative day 1

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Boston Children's Hospital

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Enid Martinez, MD, Boston Children's Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

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Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
August 1, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 30, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 30, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 2, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 3, 2017

First Posted (Estimated)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 5, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 14, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB-P00024070

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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