Fractional Exhaled Nitric Oxide and Asthma Control in Moderate to Severe Asthma Patients Treated With Omalizumab: A Retrospective Cohort Study
Bibliographic record
Abstract
Abstract RATIONALE: In patients with moderate to severe asthma treated with omalizumab, there is limited data on the use of type-2 inflammatory biomarkers such as fractional exhaled nitric oxide (FeNO) in monitoring their disease. We hypothesized that, among patients receiving omalizumab, those with higher FeNO levels are at increased risk of experiencing uncontrolled asthma compared to those with lower FeNO levels. METHODS: This is a retrospective cohort study conducted at Sherbrooke University Hospital assessing adult patients with moderate to severe allergic asthma who have been receiving omalizumab for at least four months. Patients with significant respiratory comorbidities, active smokers, and those treated for active exacerbation were excluded. Patients were categorized based on their FeNO levels into two groups: low (<20 ppb) and high (≥20 ppb). As primary analysis, the differences according to asthma control proportion was assessed based on GINA definition. As secondary analysis, differences between groups were evaluated based on the following components of asthma control: Asthma Control Questionnaire-5 (ACQ-5), exacerbations history in the past year, and forced expiratory volume in 1 second (FEV1). An additional categorization combining FeNO and blood eosinophil count (BEC) was performed, and differences between the resulting groups were evaluated in term of asthma control components. RESULTS: Among the 22 recruited patients, 17 (77%) were women, with a median [interquartile range] age of 49 years [35-58], and the median FEV1 (% of predicted) was 89% [78-92]. The comparison of groups of patients according to the level of FeNO did not demonstrated any significant difference on the proportion of patients with controlled asthma (FeNO < 20: 55 % vs FeNO ≥20: 78 %, chi-square, p = 0.4). Similarly, no significant difference was demonstrated comparing their ACQ-5 scores (1.4 vs 1.5, p=1) and FEV1 (85% vs 84%, p=0.7). Among patients with both type 2 inflammatory markers high (FeNO ≥ 25 ppb and eosinophils ≥ 0.15x10^9/L), a greater proportion of patients experienced at least one exacerbation in the past year compared to those with low biomarkers, although this difference was not statistically significant (OR = 4.63 [0.59-59.29], p = 0.2) (Figure). CONCLUSION: Level of FeNO was not associated to asthma control in a small population of patients with allergic asthma on omalizumab. The lack of a statistical relationship between type 2 biomarkers and exacerbations may be attributed to the discordance between symptoms and inflammation, and the nature of the allergic inflammatory cascade in allergic asthma.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".