Evidence map›Paper›PMID 41497329›Full record

ArticleERJ open research2026

A novel method to assess airway eosinophilia using sputum plugs.

Zil Patel, Nadia Suray Tan, Alex Huynh, Katherine Radford, Nicola Calma, Lisa Harper, Snehal Somalwar, Chynna Huang, Melanie Kjarsgaard, Anmar Ayoub and 2 more

Abstract read
In one paragraph

Article in ERJ open research, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

12 authors.

Zil PatelDepartment of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON, Canada.ORCID https://orcid.org/0000-0002-8514-1843
Nadia Suray TanDepartment of Medicine, McMaster University, Hamilton ON, Canada.
Alex HuynhDepartment of Medicine, McMaster University, Hamilton ON, Canada.ORCID https://orcid.org/0009-0009-9103-1374
Katherine RadfordResearch Institute of St Joe's, St Joseph's Healthcare Hamilton, Hamilton ON, Canada.
Nicola CalmaResearch Institute of St Joe's, St Joseph's Healthcare Hamilton, Hamilton ON, Canada.
Lisa HarperResearch Institute of St Joe's, St Joseph's Healthcare Hamilton, Hamilton ON, Canada.
Snehal SomalwarResearch Institute of St Joe's, St Joseph's Healthcare Hamilton, Hamilton ON, Canada.
Chynna HuangResearch Institute of St Joe's, St Joseph's Healthcare Hamilton, Hamilton ON, Canada.
Melanie KjarsgaardResearch Institute of St Joe's, St Joseph's Healthcare Hamilton, Hamilton ON, Canada.
Anmar AyoubDepartment of Medicine, McMaster University, Hamilton ON, Canada.
Parameswaran NairDepartment of Medicine, McMaster University, Hamilton ON, Canada.
Manali MukherjeeDepartment of Medicine, McMaster University, Hamilton ON, Canada.ORCID https://orcid.org/0000-0002-7924-7211

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Sputum cytology utilising routine dithiothreitol (DTT) processing is a well-established method to assess airway eosinophilia. However, the multi-step nature of this protocol requires substantial resources, thereby limiting its broader clinical applicability. To address this, we evaluated formalin-fixed, paraffin-embedded (FFPE) sputum plugs as a simplified method for measuring airway eosinophilia. Methods: Excess sputum plugs from 113 patients with complex airway disease and 16 asthma patients on corticosteroid or monoclonal antibodies were fixed in 10% formalin and embedded in paraffin (Sputum-Minimising Processing, Maximising Clinical Outcomes (SSIMPLE) method). FFPE blocks were sectioned, stained with haematoxylin and eosin, and assessed by four blinded observers, who performed a differential cell count on 400 total nonsquamous cells. Eosinophil proportions were then compared between matched FFPE and DTT-processed sputum slides. Airway eosinophilia was defined as ≥2.2% sputum eosinophils in DTT-processed samples. Results: Of the 113 FFPE slides, 96% were adequate for cellular analysis, with 90% having matched DTT-processed sputum slides. The SSIMPLE method demonstrated excellent interobserver reproducibility (consistency: 0.975; agreement: 0.976). Eosinophil proportions obtained from SSIMPLE and DTT processing were significantly correlated (ρ=0.9, p<0.0001) and showed agreement (Bland-Altman, -0.38±9.51). A cut-off of 2.6% detected airway eosinophilia with high sensitivity (85.4%) and specificity (93.0%) using the SSIMPLE method, showing strong agreement with the routine DTT method, as indicated by an area under the curve of 0.957. Additionally, the method effectively assessed treatment responsiveness to monoclonal antibody therapy. Conclusion: The SSIMPLE method is a reliable, noninferior approach to DTT processing for detecting airway eosinophilia in complex airway diseases, with high reproducibility and strong concordance in monitoring treatment responsiveness.

Identifiers

PMID41497329
PMCPMC12766467

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.