For individual patients with poorly-controlled asthma, nasal and pharyngeal eosinophil peroxidase (EPX) levels are strongly associated with the eosinophil percentage of induced sputum, according to a study published online Dec. 8 in Allergy.

According to study results, Mayo Clinic researchers observed a significant difference in sputum EPX levels between asthma and control subjects. EPX levels measured in nasal and pharyngeal swab samples derived from the same patients were significantly different between asthma and control subjects.

“The use of nasal or pharyngeal swabs may represent a clinically relevant diagnostic metric whose simplicity of use would provide a novel point-of-care assay in the management of asthma patients,” researchers said.