A potential new diagnostic test for kidney damage associated with antibiotic use in cystic fibrosis (CF) patients is able to detect problems before the damage becomes too significant. From the University of Liverpool, scientists focus on two specific proteins as new biomarkers for kidney damage in CF.
CF is a progressive genetic disease causing constant lung infections. The defective gene in CF results in a buildup of thick, sticky mucus in many organs, including the lungs, that increases the risk of infection and limits the ability to breathe. A common bacteria causing infection in CF patients is Pseudomonas aeruginosa. Antibiotics called aminoglycosides are used to treat this type of bacterial infection, but they can also cause damage to the kidneys.
The major problem with aminoglycoside-related kidney damage is that current diagnostic methods are not able to detect damage before it becomes too great. Current diagnostic methods focus on the measurement of serum creatinine, either in the blood or urine, which provides a measure of how well the kidneys are filtering waste products from the blood.
Creatine is a chemical waste product that is filtered out of the blood into the urine by a healthy kidney. However the test only signals the presence of acute kidney injury (AKI) when significant kidney damage has already occurred. Researchers knew they needed a test that illustrates when and where the kidney damage is before the loss is too great.
Researchers conducted a study with 150 children and young adults diagnosed with CF. With urine samples taken, the could have two proteins measured, KIM-1 and NGAL, during and after exposure to aminoglycosides. Concentrations of both proteins increased during exposure to the antibiotics, but serum (blood) levels of creatinine had not yet increased. This finding indicated that the increase of the two proteins could be used to identify potential AKI before significantly harmful damage occurred.
"Our research shows that KIM-1 may be a useful, non-invasive, biomarker of acute and chronic kidney damage associated with exposure to aminoglycosides in patients with CF, but its clinical utility needs to be further evaluated in prospective studies,” concluded study leader Dr. Steve McWilliam.
More than 30,000 people are living with CF in the United States, and the median survival age is close to 40.
The present study was published in the journal Scientific Reports.
Sources: Cystic Fibrosis Foundation, Mayo Clinic, University of Liverpool
