Diagnosis of Abdominal Pain Using RNA Levels: The NATURAL Study (NATURAL)

May 6, 2026 updated by: True Bearing Diagnostics, Inc.

Neutrophil Activation Test Using RNA Levels to Assist in the Diagnosis of Abdominal Pain: The NATURAL Study

The NATURAL Study is a prospective, observational, pragmatic study of RNA biomarkers of infections to aid in the diagnosis of abdominal pain.

Summary of Research Study:

Hypothesis: A genomic-derived panel of 6 RNA biomarkers present in stabilized whole blood will provide diagnostic information about the presence of bacterial, biofilm, and viral infections in the abdomen. We hypothesize that biomarkers will be more than 90% sensitive with a high (>90%) negative predictive value for IAI.

Research Design: The project design is a prospective, pragmatic, observational study. The NATURAL Study will be sponsored by True Bearing Diagnostics, Inc., and performed at 5 or more academic medical centers. Patients with suspected intra-abdominal infections (IAIs), such as appendicitis, diverticulitis, acute cholecystitis, pancreatitis, peritonitis, pyelonephritis, and abscess are candidates for this study. This is a broad category of patients that are defined by the suspicion of an internal abdominal infection, usually involving some type of advanced imaging analysis, such as CT scan or ultrasound. All participants will be consented for this observational, minimal-risk study prior to venipuncture. Ultimately, The NATURAL Study will determine the positive agreement (~sensitivity) and negative agreement (~specificity) of the TruNAV RNA biomarkers in relation to the clinical diagnosis of the presence or absence of an IAI, based on CT scans and/or surgical confirmation, the current standard of care for diagnosis of IAI.

Objective: To validate a novel RNA fingerprint in ED patients with suspected IAIs.

The NATURAL Study is designed to determine the accuracy of novel RNA biomarkers for diagnosis of IAI in patients suspected of having IAI. Subgroup analysis will analyse RNA biomarker for multiple types of actual and suspected IAIs (appendicitis, diverticulitis, acute cholecystitis, pancreatitis, peritonitis, pyelonephritis, and abscess.)

Subjects: Approximately 1,000 ED patients presenting with abdominal pain that are candidates to receive CT or other confirmatory diagnostics will be enrolled.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The NATURAL Study Neutrophil Activation Test Using RNA Levels to aid in the diagnosis of abdominal pain.

A prospective, observational, pragmatic study of RNA biomarkers of infections to aid in the diagnosis of abdominal pain.

Summary of Research Study:

Hypothesis: A genomic-derived panel of 6 RNA biomarkers present in stabilized whole blood will provide diagnostic information about the presence of bacterial, biofilm, and viral infections in the abdomen. We hypothesize that biomarkers will be ~90% sensitive with a high (>90%) negative predictive value for IAI.

Research Design: The project design is a prospective, pragmatic, observational study. The NATURAL Study will be sponsored by True Bearing Diagnostics, Inc., and performed at 5 or more academic medical centers. Patients with suspected intra-abdominal infections (IAIs), such as appendicitis, diverticulitis, acute cholecystitis, pancreatitis, peritonitis, pyelonephritis, and abscess are candidates for this study. This is a broad category of patients that are defined by the suspicion of an internal abdominal infection, usually involving some type of advanced imaging analysis, such as CT scan or ultrasound. All participants will be consented for this observational, minimal-risk study prior to venipuncture. Ultimately, The NATURAL Study will determine the positive agreement (~sensitivity) and negative agreement (~specificity) of the TruNAV RNA biomarkers in relation to the clinical diagnosis of the presence or absence of an IAI, based on CT scans and/or surgical confirmation, the current standard of care for diagnosis of IAI.

Objective: To validate a novel RNA fingerprint in ED patients with suspected IAIs.

The NATURAL Study is designed to determine the accuracy of novel RNA biomarkers for diagnosis of IAI in patients suspected of having IAI. Subgroup analysis will analyze RNA biomarker for multiple types of actual and suspected IAIs (appendicitis, diverticulitis, acute cholecystitis, pancreatitis, peritonitis, pyelonephritis, and abscess.)

Subjects: Approximately 1,000 ED patients presenting with abdominal pain that are candidates to receive CT or other confirmatory diagnostics will be enrolled.

Inclusion Criteria:

Subjects must meet all of the inclusion criteria listed below to be eligible for the Study:

  1. Age >6 years old
  2. Abdominal pain of likely non-traumatic origin
  3. Possible internal abdominal infection (IAI, see defined criteria)
  4. Ability to provide informed consent/assent
  5. Intent to order abdominal CT, ultrasound, endoscopy, or surgery

Exclusion Criteria:

Subjects with any one of the exclusion criteria listed below will not be eligible for treatment under this Study:

  1. Any emergent situation where delay could be detrimental
  2. Hemodynamically unstable (see age-appropriate criteria)
  3. Prisoner
  4. Inability to provide informed consent/assent
  5. Non-English speaking

Patient Screening and Consent:

Prior to screening, each subject will be informed in detail about potential benefits of the results of TruNAV as well as of any risks and discomforts that are expected. The basic elements of informed consent as specified by International Conference on Harmonization (ICH) Good Clinical Practices (GCP) will be followed. Written consent will be obtained from each participant to be treated in the STUDY, by using the Investigational Review Board (IRB)-approved Informed Consent Form (ICF) prior to the conduct of any STUDY-related activity. Each subject will be given a copy of the signed and dated ICF. The participants will also be instructed that their participation is voluntary, and they are free to withdraw their consent and discontinue participation in the STUDY at any time without prejudice. In the case of persons younger than the age of consent (<18 years), parental consent and patient assent will be obtained. Patient assent is not needed for ages 6-7.

Sample Collection:

After appropriate screening and consent, the study tubes (4) marked with the study code ID, containing a special RNA preservative are drawn by venipuncture, or indwelling IV line if available.

Sample Preparation and Shipping The four (4) TruNAV tubes are collected: 4 tubes (Tempus) should all be shaken vigorously 10 times and then they rest at room temperature for 2 hours.

The Tempus tubes are shipped to the Sponsor in the packing provided via FedEx at the end of each day.

Clinical Data Extraction

1.1 Demographics, Medical History, and Clinical Assessment All of the data collection parameters are described in detail in the web-based electronic data collection (EDC) tool (iMednet). A general description is provided here for review and discussion.

1.2 Standard of Care Diagnostics As stated, no aspect of the clinical treatment of the patient should be altered because of this Study. However, the Sponsor is very interested in recording all of the tests and results performed.

1.2.1 Clinical Data

  • Demographic data: race, sex, age, height, weight
  • Blood pressure, heart rate, temperature 1.2.2 Laboratory Tests
  • absolute lymphocyte count
  • absolute neutrophil count
  • neutrophil/lymphocyte ratio (NLR)
  • %bands (if ordered)
  • Serum lactate levels
  • Creatinine
  • Procalcitonin 1.2.3 Imaging
  • Radiologist interpretation of CT/MR scan suggesting presence/absence of an internal infection. (non-invasive)
  • Radiologist interpretation of ultrasound of the abdomen suggesting presence/absence of an internal infection. (non-invasive)
  • Any type of upper or lower GI imaging by ingestion of contrast agents.
  • Any type of camera-based 'pills' that are ingested for diagnostic purposes. 1.2.4 Surgery
  • Any invasive surgical confirmation of a disorder by colonoscopy, endoscopy or laparotomy.

1.3 Standard of Care Treatment (if provided to patient) 1.3.1 Antibiotics, Antivirals, and Antifungals The specific types of these drugs, with doses and frequencies should be recorded.

1.3.2 Other Medication or Non-Surgical Treatment Other common medications that might be ordered should be recorded. This includes, but is not limited to: non-steroidal inflammatories (NSAIDs), steroids, such as prednisone, diuretics, laxatives, etc.

1.3.3 Surgical Treatment Surgery should be broadly interpreted to mean any invasive procedure. This could include a range of procedures from upper or lower GI imaging by endoscopy or laparoscopy or upper/lower GI contrast imaging.

1.4 Disposition or Resolution The final disposition of the patient at this visit is a specific endpoint of the Study. A typical range of dispositions is specified in the online collection tool: Admitted to floor, ICU, or surgery. Discharged. Death.

1.4.1 Clinical Assessment A particularly important endpoint of the Study is the final clinical assessment of a) the final confirmed diagnosis of an infectious disorder, ie appendicitis, and, b) of the clinically adjudicated likelihood of an infectious cause. These 2 dimensions are related, but can differ in important ways. For instance, a diagnosis of 'kidney stones' could have symptoms or lab results indicative of a related or unrelated infection, or, particularly in the case of non-obstructive stones that pass relatively easily, may have no infectious symptoms or lab results.

1.5 Long Term Follow Up Long term follow up is not required past the 30 day collection window. Only follow-up that is a normal part of the standard of care for the patient is required for the Study. No additional follow-up is needed.

Study Type

Observational

Enrollment (Estimated)

1000

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 Locations

  • United States
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20010
        • Recruiting
        • Children's National Hospital
        • Contact:
        • Principal Investigator:
          • Elaise Hill, M.D.

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

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

Patients presenting to a physician at an Emergency Department or Gastroenterology Clinic with a primary complaint of abdominal pain that the physician believes could have an infectious etiology.

Description

Inclusion Criteria:

Age > 7 yr old Abdominal pain of likely non-traumatic origin Risk of intra-abdominal infection (see IAI signs) Ability to provide informed consent/assent Potential to order abdominal CT, ultrasound, endoscopy, or surgery for possible IAI

Exclusion Criteria:

Any situation where delay could be detrimental Hemodynamically unstable (see age-adjusted criteria) Prisoner or other involuntary detainee Inability to provide informed consent/assent

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

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
Abdominal Pain
Patients presenting to a physician with abdominal pain of potential infectious cause
Diagnostic test: TruNAV, an RNA-based blood test for host immune activation by infections

TruNAV is a qualitative in vitro Diagnostic Multivariate Index Assay (IVDMIA) using digital PCR to quantitatively measure for the presence of Neutrophil ActiVation markers to assist in the diagnosis of non-acute abdominal infection (e.g., appendicitis, gall bladder cholecystitis, gastroenteritis, diverticulitis, pyelonephritis, epiploic appendagitis, urinary tract infection (UTI), pelvic inflammatory disease) for in-patient and out-patient care settings. TruNAV uses the levels of 6 human RNA biomarkers to read the level and type of activation of circulating immune cells in whole blood.

TruNAV reports to the healthcare provider a Bacterial Infection Score, BioFilm Score, and Viral Score, indicating whether each score is below or above threshold levels.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Agreement to Clinical Adjudication of Infection
Time Frame: The clinical assessment of infection includes up to 30 days of relevant data after the initial patient visit.
The primary outcome is the agreement (concordance) of the experimental TruNAV blood test with the clinically adjudicated diagnosis of intraabdominal infection, such as appendicitis.
The clinical assessment of infection includes up to 30 days of relevant data after the initial patient visit.

Collaborators and Investigators

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

Sponsor

True Bearing Diagnostics, Inc.

Investigators

  • Principal Investigator: Aamir Ali, M.D., True Bearing Diagnostics, Inc.

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

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 17, 2026

Primary Completion (Estimated)

April 1, 2027

Study Completion (Estimated)

September 1, 2027

Study Registration Dates

First Submitted

May 6, 2026

First Submitted That Met QC Criteria

May 6, 2026

First Posted (Actual)

May 12, 2026

Study Record Updates

Last Update Posted (Actual)

May 12, 2026

Last Update Submitted That Met QC Criteria

May 6, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TBDI-05

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

IPD could include sequence data that could construed as identifiable. If stripped of any potential sequence or other personal data, the IPD will be disclosed.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

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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