A new study led by a team from the Research Institute of the McGill University Health Centre (RI-MUHC) and Cystic Fibrosis Canada strongly supports the benefits of newborn screening programs for cystic fibrosis (CF). The study, “The benefits of newborn screening for cystic fibrosis: The Canadian experience”, was published in the Journal of Cystic Fibrosis.
Overwhelming evidence reinforces the establishment of newborn screening programs for CF in order to improve the survival, long-term growth, and health outcomes of people living with the disease, according to the report. But, while newborn screening for CF is widely adopted in several European countries, Australia, New Zealand, and most of North America it is not accepted in Quebec, Canada.
Though several CF screening tests exist, newborn screening most often consists of a two-step test using immunoreactive trypsinogen (IRT) from a blood spot obtained during the first few days of life, followed by a search for common mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. A positive CF screen results in a referral to a CF clinic to confirm the diagnosis through additional blood and sweat tests. When babies with a high risk for CF are identified and the diagnosis is confirmed, education and treatment begins, typically within the first 4 to 6 weeks of life.
The study’s first author, Dr. Denise Mak, program manager at Healthcare at Cystic Fibrosis Canada, said in a press release that the team questioned if newborn screening for CF was beneficial “given the changes in clinical management for CF.”
“We wanted to know in an unbiased way whether newborn screening was beneficial to Canadian CF patients, or whether current treatments would allow those patients diagnosed because of symptoms, to catch up in their overall health,” Mak said.
The team of researchers used data between 2008 and 2013 from the Canadian CF Registry. They compared the rates of respiratory infections and markers of nutritional status in those diagnosed through newborn screening to those who were diagnosed clinically within the same time period. The study included 303 subjects; 201 in the newborn screening group and 102 from the non-newborn screening group.
The researchers found a higher rate of pseudomonas aeruginosa infection in children who were not screened as newborns. By age 6, more than 60% of those not screened had been infected with pseudomonas aeruginosa at least once, while less than 30% of the newborn tested patients had contracted the infection. The researchers also found that children diagnosed through newborn screening were diagnosed at earlier ages; from less than one month old to 4.9 months old.
“Over the six-year time period, we found that newborn screening for CF resulted in better nutrition, fewer children being infected with pseudomonas aeruginosa, and fewer and shorter hospitalizations in Canadian CF children,” Mak said.
The study’s senior author, Dr. Larry Lands, director of Pediatric Respiratory Medicine and CF clinic at the Montreal Children’s Hospital at MUHC and a professor in the Department of Pediatrics at McGill University, said the study shows that newborn screening is an opportunity for early preventative intervention.
“Children with CF who are diagnosed through newborn screening are healthier and will benefit more from new treatments,’’ Lands said.
CF is a life-limiting inherited condition caused by mutations in the CFTR gene that controls the movement of salt and water in and out of cells. The disease causes mucus to gather in the lungs and digestive system and create a range of challenging symptoms. It is estimated that one in every 3,600 children born in Canada has CF.