Study To Assess Biomarker as Indicator of Whether LRTIs Improve with Antibacterial Treatment

A new clinical trial sponsored by NIAID aims to determine whether low blood levels of the protein procalcitonin can reliably indicate whether a person’s lower respiratory tract infection will improve with antibiotic treatment.

Lower respiratory tract infections (LRTIs) can cause a variety of symptoms, including persistent coughing, wheezing, chest pain, fever and rapid or difficult breathing. Health care providers often prescribe a course of antibiotics as standard treatment without knowing for certain whether an infection is bacterial or viral. Taking antibiotics for viral infections is not only ineffective but can also introduce potential side effects and promote antimicrobial resistance.

Procalcitonin (PCT) is normally produced by the healthy human body in minute quantities and serves as a precursor to calcitonin, a hormone that helps regulate calcium levels. Currently, medical professionals are able to test patients’ blood for high PCT levels, which are an indicator of bacterial sepsis, a life-threatening complication of infection that triggers inflammation throughout the body. The researchers leading the new clinical trial theorize that low PCT levels in patients with LRTIs may indicate that the infection is viral, not bacterial.

“Health care providers and patients benefit from precise diagnostic tests to guide treatment decisions,” said NIAID director Dr. Anthony Fauci. “An effective biomarker for confirming that a lower respiratory tract infection is viral and thus not treatable with antibiotics would be a significant development in our collective efforts to reduce inappropriate use of antibiotics and combat antimicrobial resistance.”

The study is being led by principal investigator Dr. Ephraim Tsalik of Duke University and the Durham VA Health Care System in Durham, N.C.