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Asthma patients showed elevated sputum neutrophils when exposed to occupational asthmagens

Sputum neutrophils were elevated in adults diagnosed with severe asthma and exposed to workplace asthmagens, according to a recent study in BMC Pulmonary Medicine.

“We found that approximately one-third of adults with poorly controlled asthma had occupations with identifiable exposures to occupational asthmagens whose symptoms may exacerbate or worsen their asthma,” the researchers wrote.

The investigators recruited 66 nonsmoking adults with refractory asthma from the respiratory department at John Hunter Hospital in Australia. The participants’ previous smoking history and exposure to cigarette smoke were taken into account by the researchers.

Forty-six participants had no exposure to any identified asthmagen, including latex, wood dust, cleaning products and exhaust fumes. Of the remainder, 11 reported working in high-risk environments with asthma triggers. The researchers divided the participants by exposure and age at asthma diagnosis: those aged 30 years or older and those aged less than 30 years.

Participants exposed to workplace asthmagens, particularly those in the older asthma-diagnosed group, were more than three times likely to have elevated sputum neutrophils (P=.03) than nonexposed participants.

Researchers indicated the percentage of neutrophils was significantly affected by exposure.

“A diagnosis of asthma at more than 30 years of age was associated with a 20% increase of sputum neutrophils, and 70% of participants in the exposed group showed evidence of airway inflammation, half of those with neutrophilic bronchitis,” the researchers concluded.

Disclosure: The researchers report no relevant financial disclosures.