Many rescue workers present during the World Trade Center (WTC) disaster of September 11, 2001 (9/11) have small airways dysfunction that is unique to the airborne ash and dust exposure they experienced on that day, according to recent research released as an abstract for the American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting.

“Seventeen years after exposure to the WTC disaster, exposed patients experience small airways dysfunction characterized by increased distal airways resistance and reactance not explained by obesity, smoking history, or allergic disease,” Dennis L. Caruana, first author and an MD degree candidate at the Yale School of Medicine in New Haven, CT, said in an interview with MD /alert.

These rescue workers were exposed to the ash and dust of the WTC disaster for days and even months, which made them uniquely susceptible to lung injury, Mr. Caruana and colleagues wrote in their study abstract for the meeting.

The investigators performed a retrospective chart review of 18 rescue workers on 9/11 who had undergone spirometric lung function, airway hyperresponsiveness and distal airways narrowing tests as well as pre- and post-bronchodilator reversibility tests at a local outpatient allergy and asthma clinic. These patients had appropriately managed allergic hypersensitivity using biological modifiers, asthma controllers and relievers, and immunotherapy, but were referred from the World Trade Center Health Program for allergy and immunology treatment with new symptoms. Caruana and colleagues examined impulse oscillometry results (R5-R20) to assess airway hyperresponsiveness and distal airways narrowing, and spirometry (FEF25-75) to assess lung function in these patients as a result of fallout specific to the WTC disaster.

Overall, 12 of 18 rescue workers (66.6%) developed new-onset respiratory symptoms, but still experienced severe and persistent symptoms resembling permanent small airway dysfunction as measured by FEF25-75. Ten of 18 rescue workers (55.5%) experienced symptoms of distal airway narrowing (R5-R20), while all patients had airway hyperresponsiveness (index X5). Although patients managed their symptoms with steroid controllers and relievers, biologic modifiers such as anti-immunoglobulin E and dupilumab, and allergic immunotherapy, the findings persisted, and investigators also noted rescue workers had partial post-bronchodilator reversibility.

“Many of our patients referred to us from the World Trade Center Health Program had airway hyper-responsiveness that was not responding well to bronchodilator medications and impulse oscillometry, a test better at detecting distal airways dysfunction as compared to spirometry, had never before been conducted pre- and post-bronchodilator to assess reversibility,” Mr. Caruana said.