Sweat from Infants with CF May Contain Biomarkers That Help Doctors Treat the Disease, Study Reports

Sweat from infants with cystic fibrosis contains substances that could be used as biomarkers of the disease and even identify new disease mechanisms, a study reports.

The research, published in the journal ACS Central Science, was titled “The Sweat Metabolome of Screen-Positive Cystic Fibrosis Infants: Revealing Mechanisms beyond Impaired Chloride Transport.”

Scientists say the gold standard for diagnosing CF remains the sweat chloride test, which measures the amount of chloride — one of the body’s most important electrolytes — in a person’s blood.

The test results can be ambiguous, however. This is especially true when “chloride levels are intermediate,” as opposed to high or low, the researchers wrote.

If doctors had biomarkers they could use in conjunction with the test, they might be able to do a better job of diagnosing the disease, treating patients and predicting outcomes, according to the team.

Scientists know that levels of certain metabolites are associated with the outcomes of many diseases, supporting their role as potential biomarkers. Metabolites are substances necessary for cells’ metabolism.

The problem with using metabolites as CF biomarkers was that scientists had never determined the metabolic composition of patients’ sweat. Canadian researchers decided to remedy that.

“Sweat contains lots of information related to human health that researchers have not fully analyzed, and we found some unexpected chemicals associated with CF,” Philip Britz-McKibbin, a professor in the Department of Chemistry and Chemical Biology at McMaster University, said in a press release. He was the study’s lead author.

The McMaster team analyzed the metabolic composition of the sweat of 18 infants with cystic fibrosis and 50 infants without the disease. The children were at the McMaster Children’s Hospital and the Hospital for Sick Children in Toronto.

The analysis showed that sweat from babies with CF contained several chemicals besides chloride.

Researchers also discovered that children with the disease had significantly lower levels of a metabolite that stimulates sweat production – pilocarpic acid – and a plasticizer metabolite, or chemical compound used in making plastics.

The results suggested that testing for the biomarkers could be a way to clarify an unclear chloride sweat test. The findings also indicated that mechanisms besides the ones scientists are aware of may underlie CF. Investigating these mechanisms could lead to new therapy approaches, the researchers said.

“The easier it is to detect CF, the earlier it can be diagnosed, and the better people’s chances are at living a longer, healthier life,” Joanna Valsamis, chief healthcare, research and advocacy officer at Cystic Fibrosis Canada, said of the results.

“CF Canada invests heavily in research that aims to improve the lives of people living with CF, and findings such as those from Dr. Britz-McKibbin are crucial to our understanding of the disease,” Valsamis added.