Design: Prospective comparative imaging study with individual plug-level longitudinal annotation on CT
Population: 32 adults with moderate to severe asthma: 22 given dupilumab fortnightly for at least 16 weeks, 10 controls
Primary outcome: Mucus plug count, volume and radiodensity, and plug-level fate (resolved, persistent, new)
Effect: Resolved plugs 91% vs 58% (P<.0001); persistent plugs 9% vs 42% (P<.0001); new plugs median 1 vs 6 (P=.0008); complete resolution in 36% vs 10% of participants; radiodensity of persistent plugs fell from -422 to -569 Hounsfield units (P=.009)

CT-visible mucus plugs in asthma are not incidental — they track with airflow obstruction and with ventilation defects on imaging. Dupilumab is known to reduce the overall mucus score. This study asked a more granular question: what happens to individual plugs.

Thirty-two adults with moderate to severe asthma were scanned twice; 22 received dupilumab fortnightly for at least 16 weeks and 10 served as controls. Every visible plug was annotated and tracked, and classified as resolved, persistent in the same location, or newly formed.

Ninety-one per cent of plugs resolved with dupilumab against 58% in controls, persistent plugs fell from 42% to 9%, and new plug formation dropped from a median of six to one. Complete resolution occurred in 36% of treated participants against 10% of controls. The radiodensity of plugs that persisted fell after treatment, from -422 to -569 Hounsfield units, and new plugs forming under treatment were also less dense — a plausible signature of less tenacious mucus. Reductions in plug burden went with better FEV1, FEV1/FVC and xenon MRI ventilation defect percentage.

The caution sits in the last finding: participants with incomplete resolution still had higher ventilation defect percentages. Low-density residual plugs are not nothing.

Where CT is already available in severe asthma, mucus plugging is a treatable trait worth looking for
Do not order CT solely to count plugs; this is a mechanistic study, not a monitoring protocol
Note that most treated patients had incomplete rather than complete resolution
Residual low-density plugs still tracked with ventilation defects
Sample size is 32; treat every percentage here as illustrative

Why it matters

It reframes mucus plugs from a structural consequence of chronic asthma into something that forms, resolves and can be prevented.

The statistics, in plain English

With 22 treated and 10 control participants, the striking percentages are computed over individual plugs rather than over people, so hundreds of plugs come from a few dozen patients and the observations are not independent of one another. That inflates apparent precision considerably. The imaging comparisons were not blinded in a way the report establishes, and the control group is small enough that its 58% resolution rate could easily be several points either way.