Diagnosis of occupational eosinophilic bronchitis

Eosinophilic bronchitis was defined as an increase in sputum eosinophilia of >=3% 24 hours post SIC, with no NSBR and a fall in FEV1 <15%. The eosinophilic bronchitis group had more cough, higher FEV1 and a shorter period of work-related symptoms than those with a positive SIC, raising the possibility that this is an early stage of eosinophilic occupational asthma rather than a separate disease. Measuring sputum eosinophilia is unpleasant for the patient and time consuming for the staff, unfortunately this study showed that increases in FeNO (which is much easier to measure) had a poor sensitivity for detecting the >3% increase in sputum eosinophilia (an increase of 8ppb had a specificity of 90% and a sensitivity of 43%). This study critically depends on the 15% cut off for a positive SIC, the FEV1 changes post SIC are not given in the paper. I would be much happier if the disease was defined by changes found following usual exposures at work, rather than the artificial (but controlled) exposures in the laboratory.

References

	Wiszniewska M, Dellis P, van Kampen V, Suojalehto H, Munoz X, Walusiak-Skorupa J, Lindström I, Merget R, Romero-Mesones C, Sastre J, Quirce S, Mason P, Rifflart C, Godet J, de Blay F, Vandenplas O, European network for the PHenotyping of OCcupational ASthma (E-PHOCAS);, Characterization of Occupational Eosinophilic Bronchitis in a Multicenter Cohort of Subjects with Work-Related Asthma Symptoms, J Allergy Clin Immunol Pract., 2020;:,https://doi.org/10.1016/j.jaip.2020.08.056

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