What is the IRT test?
Immunoreactive trypsinogen (IRT) is used as part of some newborn screening programs to screen for cystic fibrosis (CF). It may be used in conjunction with a sweat chloride test and/or a cystic fibrosis gene mutation panel to help identify CF. IRT may also sometimes be used to help detect acute pancreatitis.
What is a normal IRT level?
We found a mean IRT level of 79.16 ng/mL and a maximum of 367 ng/mL in one patient with CF that carried two severe variants. When it came to the sweat chloride test, most measurements (96.1%) were normal, that is, below the established threshold of 50 mmol/L, with a mean value of 30.56 mmol/L.
How accurate is the IRT test?
b-IRT levels had a low predictive accuracy in correctly identifying the four different groups (c-index: 0.60), but the accuracy was high in discriminating between classic CF and carrier or noncarrier status in neonates positive to NBS.
What is a positive IRT?
In Australia it is known 94% of those with eventual diagnosis of CF have a positive IRT on newborn screen. Samples with a raised IRT (defined as highest 1% of values) are then screened for common CF gene mutations. Each centre has a slightly different gene panel; currently 40-50 of the most common genes are sequenced.
What causes high IRT in newborn?
Most likely the IRT level is very high because some of your baby’s meconium (first bowel movement) got on the newborn screening card or because your baby was stressed at birth.
What is the universal newborn screening?
Newborn screening is a public health service done in each U.S. state. Every newborn is tested for a group of health disorders that aren’t otherwise found at birth. With a simple blood test, doctors can check for rare genetic, hormone-related, and metabolic conditions that can cause serious health problems.
What causes high IRT?
What can cause elevated IRT levels in newborns?
The IRT level can be high for several reasons, including a premature or stressful delivery, or for other reasons. IRT levels also tend to be high in people who have CF. When high IRT levels are detected in the blood, the results of the newborn screening are said to be positive.