Nitric Oxide Flux and Ureagenesis in Argininosuccinate Synthetase Deficiency (ASSD)(Citrullinemia I) (NOASSD)

March 18, 2015 updated by: Brendan Lee, Baylor College of Medicine

RDCRN 5110, Nitric Oxide Flux and Ureagenesis in Argininosuccinate Synthetase Deficiency (ASSD)(Citrullinemia I)(Version 24Feb12, NIH Approved 4/5/2012)

The urea cycle consists of a series of chemical reactions through which the body converts toxic waste- nitrogen into a substance called urea that can be disposed of easily. While disposal of nitrogen is the major function of the urea cycle, recent research has shown that some enzymes of the urea cycle are also important for the production of nitric oxide. Nitric oxide is an important chemical that has many functions in the human body including regulation of blood pressure. Through this study, the investigators will study the production of nitric oxide in subjects with citrullinemia type 1 by administering stable isotopes to these subjects. Stable isotopes are harmless compounds that can be used to track and measure the production of specific compounds in the human body. The overall goal of this study is to understand if citrullinemia patients have a deficiency of nitric oxide production. This knowledge may have an impact on the treatment of patients with citrullinemia.

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.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

This is an interventional, case control study to investigate the production of nitric oxide in patients with citrullinemia type I. Through the infusion of isotopes [15N2-ureido] arginine, [5-13C,4, 4, 5, 5-D4] citrulline, [15N]citrulline, 15N sodium nitrate and [15N][18O3] potassium nitrate, the flux of citrulline and nitrate through the urea cycle pathway will be measured in conjunction with an independent measure of total plasma arginine flux. This will be informative in dissecting the contributions of de novo production of arginine vs. exogenous contribution of arginine into total body NO flux. Total body urea production will be measured by the isotopic dilution of constantly infused [18O][13C]urea. These flux measurements will be correlated with the level of residual enzyme activity and clinical phenotype in these citrullinemia patients. The investigators plan to enroll three patients with citrullinemia.

Three unaffected control subjects will also be studied.

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.
Interventional

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.
6

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

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

Study Locations

  • United States
    • Texas
      • Houston, Texas, United States, 77030
        • Baylor College of Medicine

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

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Participants must be adults (18 years and older) with confirmed diagnosis of Argininosuccinate Synthetase Deficiency (ASSD) (Citrullinemia I) who are able to perform study procedures.
  • Diagnosis of citrullinemia I must be confirmed by a >10 fold elevation of citrulline in plasma and/or decreased AS enzyme activity in cultured skin fibroblasts or other appropriate tissue and/or identification of pathogenic mutation in the AS gene.
  • Subject must be able to take oral or G-tube medication and have a history of adequate compliance of diet and treatment.
  • If a woman of child bearing potential and sexually active, participant agrees to use an acceptable method of birth control.
  • Most recent serum creatinine level must be less than or equal to 1.5 mg/dl. Serum creatinine measurement may be performed at the subject's local laboratory, but must have been obtained within one year of enrollment.
  • Participant agrees to travel to Baylor College of Medicine for the study.
  • Control subjects must be over eighteen years of age with no chronic or acute health issues.

Exclusion Criteria:

  • Pregnancy, current acute illness and current hyperammonemic episode.

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

  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: stable isotope infusion
Infusion of isotopes [15N2-ureido] arginine, [5-13C,4, 4, 5, 5-D4] citrulline, [15N]citrulline, 15N sodium nitrate and [15N][18O3] potassium nitrate,[18O][13C]urea.
Other: stable isotope infusion

Control subjects: [15N2-ureido] arginine (0.69 mg/kg); [5-13C,4,4,5,5-D4] citrulline (0.18mg/kg); 15N citrulline (0.03mg/kg); 15N sodium nitrate (0.003 mg/kg), [15N][18O3] potassium nitrate (0.03 mg/kg) and [18O][13C]urea (1 mg/kg)over 10 minutes. Followed by a 8-hour infusion of [15N2-ureido] arginine (0.69 mg/kg/hr); [5-13C,4,4,5,5-D4] citrulline (0.18mg/kg/hr), [15N][18O3] potassium nitrate (0.003 mg/kg/hr) and [18O][13C]urea (0.1 mg/kg/hr).

Citrullinemia type 1 subjects,[15N2-ureido] arginine (4.14 mg/kg); [5-13C,4,4,5,5-D4] citrulline (1.08 mg/kg); 15N citrulline (0.18mg/kg); 15N sodium nitrate (0.003 mg/kg), [15N][18O3] potassium nitrate (0.03 mg/kg) and [18O][13C]urea (1 mg/kg)over 10 minutes, followed by a 8-hour infusion of [15N2-ureido] arginine (4.14 mg/kg/hr); [5-13C,4,4,5,5-D4] citrulline (1.08 mg/kg/hr), [15N][18O3] potassium nitrate (0.003 mg/kg/hr) and [18O][13C]urea (0.1 mg/kg/hr).

Other Names:
  • stable isotopes

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
Flux of citrulline and nitrate through the urea cycle pathway will be measured in conjunction with an independent measure of total plasma arginine flux.
Time Frame: 0, 6, 7 and 7.5 hours of infusion
Endpoint data to be collected include measurement of isotopic enrichments drawn at 0, 6, 7 and 7.5 hours of infusion. Measurements will include urea, carbon-arginine, guanido-arginine, citrulline, nitric oxide, nitrate and 15N-nitrate.
0, 6, 7 and 7.5 hours of infusion

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
Total body urea production will be measured by the isotopic dilution of constantly infused [18O][13C]urea.
Time Frame: 0, 6, 7 and 7.5 hours of infusion
Endpoint data to be collected include measurement of isotopic enrichments drawn at 0, 6, 7 and 7.5 hours of infusion. Measurements will include urea, carbon-arginine, guanido-arginine, citrulline, nitric oxide, nitrate and 15N-nitrate.
0, 6, 7 and 7.5 hours of infusion

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.
Baylor College of Medicine

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: Brendan Lee, MD, PhD, Baylor College of Medicine

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.

Helpful Links

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

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.
December 1, 2012

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.
September 1, 2013

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.
September 1, 2013

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).
May 30, 2012

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.
May 31, 2012

First Posted (Estimate)

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.
June 1, 2012

Study Record Updates

Last Update Posted (Estimate)

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.
March 20, 2015

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.
March 18, 2015

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.
March 1, 2015

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.
  • H-27226

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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