The immunoreactive trypsinogen test (IRT) has been performed by law since 2015 on all newborns in Puerto Rico.
The heel prick test allows doctors to identify the condition before children have symptoms. Photomontage: Medicine and Public Health Magazine.
The heel prick test, technically known as the immunoreactive trypsinogen (IRT) test, is performed to detect early congenital diseases such as cystic fibrosisprimary congenital hypothyroidism, phenylketonuria, and congenital adrenal hyperplasia.
Cystic fibrosis
The cystic fibrosis It is a genetic disorder that affects different areas of the body, including the lungs, pancreas, liver, and intestine, causing a buildup of thick, sticky mucus in these areas.
It is estimated that there is a 25% chance that a child will be born with the illness, and 50% that he is a carrier of the gene, but does not show it. In this regard, Dr. Wilfredo de Jesús Rojas, a pediatric pulmonologist, and Jesús Meléndez Montañéz, a medical student in Puerto Rico, spoke with the Journal of Medicine and Public Health regarding the importance of the main screening tests for cystic fibrosisthe role of genes in the associated manifestations and the main treatments available for patients.
The CFTR gene, the mutation responsible for the disease
“CF can affect the skin, the way we eat and breathe. It affects all the tubes that we have in the body, since they fill up with secretions, due to a gene, the CFTR gene that is affected and the patient inherits this mutation”, explained Dr. Wilfredo de Jesús.
In this regard, Jesús Meléndez also indicated that studies have been shown in Puerto Rico, where patients who are carriers of this gene may have CF and develop pancreatitis, a derived complication.
“In the studies we have seen in Puerto Rico, if you are a carrier of one of the many variants of the CFTR gene of cystic fibrosisthere is a high probability of having the illness and develop pancreatitis without knowing it. That is why it is key to be able to diagnose this disease in advance. illness“, he added.
Heel prick test and diagnosis of cystic fibrosis
In this sense, the heel prick test becomes more important, because through the blood test of the newly born look for increased levels of immunoreactive trypsinogen (IRT), a protein produced by the pancreas that is related to cystic fibrosis.
According to the medical literature, children with CF who are diagnosed with CF illness early and begin treatment can have better nutrition, growth, and lung function. This screening test allows doctors to identify children with the condition before they have symptoms.
“During the investigation process, we realized that prior to 2015 in Puerto Rico, at least, unlike the United States, the heel prick test was not required by law to cystic fibrosistherefore, there may be a large part of the population of Puerto Rico that has cystic fibrosis or he is a carrier and doesn’t know it,” said the medical student.
Although in Puerto Rico there are no statistics on the population with cystic fibrosisit is estimated that 1 in 17,000 children are born annually with the illness.
“One of the things we know is that this condition can be presented homozygous, which is when both parents have the mutation and it passes to the child with two mutations that can be in the same component of the gene or in different areas. That patient goes to have a slightly more severe clinic than others who may be carriers of the condition”, emphasized the pediatric pulmonologist.
warning signs
The main signs that parents can identify in children with suspected cystic fibrosis is poor growth, increased secretions in the lungs, recurrent cough with phlegm, weight loss, diarrhea or even constipation, and abdominal pain. For detection, the sweat test is used to check the amount of chlorine in the skin, in addition to other genetic tests that check if the patient has mutations.
The specialist also warned that if the proper treatments are not carried out, patients may experience difficulty breathing, contract constant infections and increase the risk of colonizing bacteria that damage the lungs.
Current treatments for cystic fibrosis
“When we start treatment early, the story can be different. The patient who goes undiagnosed for a long time has a shorter life expectancy. In the past 10 years, the expectation has varied between 30 to 40 years and we understand that with the new treatments, life expectancy can increase,” added Dr. Wilfredo de Jesús.
Similarly, the professionals highlighted that recent research, treatments, and diagnostic tools have made it possible to detect the condition early, and that is the goal they have for the Puerto Rican population.
“We know that a patient born with CF needs prolonged treatments, which include therapies that they use in the morning and at night. Our pediatric patients wear a vest that vibrates to help mobilize the body’s secretions,” said Dr. Wilfredo de Jesus.
“Science is advancing with new treatments and today there are medications that try to correct this genetic problem and help the patient not need such prolonged medications. They improve lung function and maintain weight, although they are expensive treatments; it is estimated that a CF patient might spend anywhere from $10,000 to $30,000 a year on treatments,” the specialist acknowledged.
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