Defining Normal Citrulline Levels as a Diagnostic Tool for Screening of Gastrointestinal Disease in Premature Infants

Study Overview
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Brief Summary
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Since the first description of citrulline as a potential marker for intestinal function in 1998, its use has been investigated in a variety of disease processes including Short Bowel Syndrome, Celiac disease, chemotherapy and radiation induced intestinal injury, infections producing intestinal cytopathic effects like Adenovirus, and predicting rejection in intestinal transplantation. The use of citrulline levels as a diagnostic tool to predict gastrointestinal disease in the premature population has not been properly addressed. The introduction of enteral nutrition in the premature infant is a process of trial and error, knowing that the immaturity of the gastrointestinal system may lead to frequent episodes of feeding intolerance. This is augmented by the fear of the development of necrotizing enterocolitis (NEC) once feeds are commenced. NEC is a condition characterized by disruption of the intestinal epithelial barrier, a pathogenic process shared with some of the conditions mentioned above for which citrulline has proven clinically useful. A normal pattern of citrulline production has not been established in the premature population. Previous studies have shown decreased levels of glutamine and arginine in premature infants up to 10 days prior to the development of necrotizing enterocolitis. Glutamine and arginine are two amino acids closely involved in the synthesis and catabolism of citrulline. The investigators therefore hypothesize that defining a normal pattern of citrulline production in the premature population may prove to be a clinically useful diagnostic tool to screen for gastrointestinal disease.

Detailed Description
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The use of citrulline levels as a diagnostic tool to predict gastrointestinal disease in the premature population has not been properly addressed.

Official Title
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Defining Normal Citrulline Levels as a Diagnostic Tool for Screening of Gastrointestinal Disease in Premature Infants

Conditions
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Premature Newborn, Necrotizing Enterocolitis

Intervention / Treatment
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* Diagnostic Test: Citrulline samples


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. Premature infants with gestational age between <32 weeks regardless of birth weight Exclusion Criteria: Inborn errors of metabolism Need for exchange transfusion Multiple congenital anomalies Renal failure (defined as urine output <1ml/k/h >24h, creatinine >1.8, or diagnosis of non-oliguric renal failure as determined by Pediatric nephrology)
Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Gestational age < 32 weeks<br>Premature infants with gestational age between <32 weeks regardless of birth weight | Diagnostic Test: Citrulline samples<br>* Citrulline samples will be collected at the time of other lab work twice a week from enrollment until 40 weeks postconceptional age and once a week until 44 weeks postconceptional age (1 month corrected age) OR discharge from NICU(whichever is soonest). In subgroup developing NEC, citrulline samples will be collected twice a week from enrollment until discharge from NICU or death.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The primary outcome is to establish the normal pattern of citrulline concentration in the premature population, infants born <32 weeks gestation, which represents normal maturity of the intestinal glutamine pathway. | Levels of citrulline concentration in premature infants | From birth to one month corrected age (Gestational age 44 weeks) or discharge from neonatal intensive care unit (NICU) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| A secondary outcome, in the subgroup of infants who develop necrotizing enterocolitis, will be to evaluate the pattern of citrulline concentration prior to its development. | levels of citrulline concentration in prematureinfants with NEC | From birth until discharge from NICU | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Prematurity, Necrotizing Enterocolitis, Feeding Intolerance