Vaping-associated lung injury is likely a form of airway-centered chemical pneumonitis, not exogenous lipoid pneumonia, according to Yasmeen M. Butt, MD, of the University of Texas Southwestern Medical Center, Dallas, and associates.
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Dr. Butt and associates performed a review of lung biopsies from 17 patients (13 men; median age, 35 years) with a history of vaping and either suspected or confirmed vaping-associated lung injury. All cases showed patterns of acute lung injury, including acute fibrinous pneumonitis, diffuse alveolar damage, or organizing pneumonia, the authors noted in a letter to the editor published in the New England Journal of Medicine.
While no histologic findings were specific, foamy macrophages and pneumocyte vacuolization were seen in all cases, the authors added. Pigmented macrophages were occasionally present but not dominant, neutrophils were often prominent, eosinophils were rare, and granulomas were not seen. Two patients eventually died, despite treatment with glucocorticoids and maximum supportive care.
“None of our cases showed histologic evidence of exogenous lipoid pneumonia and no radiologic evidence thereof has been found; this calls into question the diagnostic utility of identifying lipid-laden macrophages or performing oil red O staining on bronchioloalveolar lavage fluid as a marker of vaping-associated lung injury, as has been proposed,” Dr. Butt and associates wrote.
No conflicts of interest were reported.
SOURCE: Butt YM et al. N Engl J Med. 2019 Oct 2. doi: 10.1056/NEJMc1913069.