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Published on: August 7, 2017
Immunoreactive trypsin levels in neonates with meconium ileus
1Department of Surgical Paediatrics, Royal Hospital for Sick Children, Dalnair Street, G3 8SJ Glasgow, Scotland.
Insights
Serum immunoreactive trypsin (IRT) screening for cystic fibrosis (CF) shows elevated levels in neonates with meconium ileus (MI). A single high IRT level warrants CF testing, irrespective of surgical issues.
Area of Science:
- Neonatal screening
- Pediatric gastroenterology
- Biochemistry
Background:
- Serum immunoreactive trypsin (IRT) is a key neonatal screening test for cystic fibrosis (CF).
- IRT levels can vary in healthy and CF neonates within the first weeks of life.
- Meconium ileus (MI) complicates approximately 15% of CF cases.
Purpose of the Study:
- To investigate serum IRT levels in neonates with CF presenting with MI.
- To compare IRT levels between neonates with simple and complicated MI.
- To compare IRT levels in CF neonates with MI against non-CF controls.
Main Methods:
- Sequential measurement of serum IRT levels in neonates with CF and MI (n=29).
- Comparison of IRT levels with non-cystic neonates/controls with intra-abdominal pathologies (n=49).
- Analysis of IRT levels based on MI complexity, surgical intervention, and clinical parameters.
Main Results:
- IRT levels were significantly higher in the CF-MI group compared to non-cystic controls (P < 0.001).
- No significant difference in IRT levels was found between simple and complicated MI groups.
- No significant differences were observed in IRT levels based on surgical intervention, pre/post-operative status, birth weight, or gestation.
Conclusions:
- Serum IRT levels are significantly elevated in neonates with CF and MI compared to non-cystic controls without MI.
- A single elevated IRT level in a neonate should prompt CF analysis, even in the presence of surgical pathology.
Abstract:
Serum immunoreactive trypsin (IRT) is used as a screening test for cystic fibrosis (CF) in neonates in many countries. Variations in IRT levels are observed in healthy and cystic neonates within the first few weeks of life. Fifteen percentage of CF neonates present with meconium ileus (MI). We hypothesised that there may be differences in serum IRT levels in cystic babies with simple and complicated MI. The aim of this study was to investigate the serum levels of IRT in neonates with CF presenting with MI. IRT levels were sequentially measured in neonates (n = 29) with CF with intestinal obstruction due to simple or complicated MI. These were compared to levels obtained from non-cystic neonates/controls admitted with a variety of other intra-abdominal pathologies (n = 49) IRT levels were significantly higher in the CF-MI group than the non-cystic controls (P < 0.001). There was no statistical difference in IRT levels between the simple or complicated MI groups. In the MI group there was no statistical difference between those who required operation, no difference between the pre- and post-operative IRT levels and no significant relationship between IRT levels and birth weight or gestation. Serum IRT levels are significantly elevated in neonates with CF and MI compared with non-cystic, non-MI neonates. The results of this observational study highlight that a single raised level of IRT in a neonate should prompt the analysis for CF regardless of any underlying surgical pathology.
