Copeptin a Potential Biomarker of Symptom Severity During Pulmonary Exacerbation, Study Shows

High levels of the peptide copeptin are associated with increased severity of cystic fibrosis (CF) in children, a study shows.

These results suggest that copeptin can be used as a biomarker to identify patients who could benefit from more aggressive treatment.

The study, titled “Evaluation of Copeptin during Pulmonary Exacerbation in Cystic Fibrosis,” was published in the journal Mediators of Inflammation.

Copeptin, a type of peptide — a short chain of amino acids that is a fundamental component of cells — is a known marker of prognosis and disease severity across many inflammatory, respiratory, and metabolic diseases.

In particular, studies have shown increased levels of copeptin in adults and children with severe pneumonia, as well as in adults who experience exacerbations of chronic obstructive pulmonary disease (COPD).

However, little is known about the role of copeptin in CF.

Now, a group of Polish researchers from Poznan University of Medical Sciences set out to investigate whether copeptin can be used as a biomarker of prognosis and symptom severity in patients with CF.

“Given the inflammatory nature of the disease as well as multiorgan involvement, including the lungs and pancreas, we hypothesized that copeptin may serve as a marker of disease exacerbation or disease progression,” the researchers said.

The team measured copeptin levels in the serum — a component of blood — of 28 pediatric CF patients, 13 of whom were in stable condition; the remaining 15 were undergoing pulmonary exacerbation. Copeptin also was measured in the sputum, which is a mixture of saliva and mucus coughed up from the respiratory tract, of 10 CF patients.

The researchers also looked at the patients’ complete blood count (CBC), body mass index (BMI), bacterial population in the sputum, lung function (using spirometry), and chest imaging (using the Brasfield score). Symptom severity was assessed using the Shwachman-Kulczycki score, and the children’s quality of life was assessed through the Cystic Fibrosis Quality of Life Questionnaire-Revised (CFQ-R).

The results showed that copeptin levels in both the serum and sputum were higher in CF patients during a pulmonary exacerbation, compared with a stable period. However, these results were not statistically significant.

Furthermore, serum copeptin levels did not correlate significantly with any laboratory markers of inflammation, pulmonary function tests results, or BMI.

Interestingly, however, the researchers found an inverse correlation between serum copeptin levels and symptom severity during pulmonary exacerbation. An inverse, or negative correlation also was found with the Brasfield score, which measures the severity of structural lung changes, during exacerbation. Together, these results suggest that “serum copeptin may correlate with the disease progression and patients’ deterioration,” the team said.

The researchers also found that copeptin levels were inversely correlated with the quality of life in people with CF, including in the domains of vitality and eating habits — specifically, loss of appetite. The correlation of copeptin to quality of life supports the peptide’s value as a measure of disease severity.

These results, the team suggests, show that copeptin could potentially be used to help identify patients with more advanced or severe disease who could benefit from more aggressive treatment.

“We reported for the first time that copeptin concentrations correlate with CF severity measured with the Shwachman-Kulczycki score which thus may be a biomarker of symptoms severity but may not be useful to detect exacerbation,” the researchers said.

However, further studies with more participants are needed to confirm these findings, the team noted.