Sputum Cellularity and MRI Ventilation Defects in Severe Asthma
Bibliographic record
Abstract
BACKGROUND: Airway inflammation is a hallmark feature of asthma characterized by elevated eosinophils and/or neutrophils. Eosinophils in sputum can contribute to ventilation defects. The functional consequence of other types of cellularity on ventilation is unknown. RESEARCH QUESTION: Xe MRI in patients with severe asthma? STUDY DESIGN AND METHODS: Xe ventilation MRI. Sputum cytometry was performed to evaluate airway inflammation and to stratify patients with asthma into 4 cellular phenotypes (paucigranulocytic, eosinophilic, neutrophilic, and mixed-granulocytic). Abnormal ventilation, quantified as the postbronchodilator MRI ventilation defect percent (VDP), was compared between asthma sputum cellular phenotypes and to healthy control participants. Demographics, clinical characteristics, and sputum cytokine levels of patients with paucigranulocytic asthma with MRI VDP above and below the upper limit of normal were also compared. RESULTS: In patients with asthma, ventilation was abnormal (MRI VDP above the upper limit of normal) for 44% (14 of 32) of those with paucigranulocytic sputum, 64% (14 of 22) with eosinophilic bronchitis, 75% (9 of 12) with neutrophilic bronchitis, and 89% (17 of 19) with mixed-granulocytic bronchitis. Compared to healthy control participants, MRI VDP was higher in participants with asthma with eosinophilic (adjusted P = .0002), neutrophilic (adjusted P = .0001), and mixed-granulocytic phenotypes (adjusted P < .0001) but not a paucigranulocytic phenotype (adjusted P = .051). Among participants with paucigranulocytic asthma, those with an MRI VDP above the upper limit of normal were older (P = .006), had higher fractional exhaled nitric oxide (P = .02), and higher CT mucus scores (P < .0001). INTERPRETATION: Our results indicate that in severe asthma, ventilation is abnormal in the presence of intraluminal cellular inflammation, irrespective of phenotype. Abnormal ventilation in paucigranulocytic asthma may be due to airway mucus and was shown to often be associated with elevated fractional exhaled nitric oxide.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".