Relevance of TH2 Markers in the Assessment and Therapeutic Management of Severe Allergic Asthma: A Real-Life Perspective
Caminati M1, Vianello A2, Chieco Bianchi F2, Festi G3, Guarnieri G4, Marchi MR2, Micheletto C5, Olivieri M6, Tognella S7, Guerriero M8, Senna G1, on behalf of the NEONET Study Group*
1Asthma Center and Allergy Unit, Verona University Hospital, Verona, Italy
2Respiratory Pathophysiology Division, University-City Hospital of Padua, Padua, Italy
3Pulmonary Unit, Verona University Hospital, Verona, Italy
4Department of Cardiologic, Thoracic and Vascular Sciences, University of Padua, Padua, Italy
5Respiratory Unit, Mater Salutis Hospital, Legnago, Italy
6Unit of Occupational Medicine, Verona University Hospital, Verona, Italy
7Respiratory Unit, Orlandi General Hospital, Bussolengo, Italy
8Department of Computer Science, University of Verona, Verona, Italy
*Denise Artioli, Elisabetta Bertocco, Lucio Bonazza, Mariangiola Crivellaro, Fabio De Conti, Annarita Dama, Giulio Donazzan, Giuseppe Idotta, Carlo Lombardi, Luigi Marino, Francesco Mazza, Stefano Nardini, Federico Reccardini, Michele Schiappoli.
J Investig Allergol Clin Immunol 2020; Vol 30(1)
Background: Although blood eosinophils are currently recognized as the main clinical marker of TH2-type inflammation, their relevance in identifying asthma severity remains a matter of debate.
Methods: Our retrospective real-life study on severe asthmatics included in the NEONet Italian database aimed to investigate the relevance of blood eosinophil count and fractional exhaled nitric oxide (FeNO) in the clinical assessment of severe asthma and their role as potential predictors of responsiveness to anti-IgE therapy. The cut-off values chosen were 300 eosinophils/mm3 and FeNO of 30 ppm.
Results: We evaluated 132 adult patients. No significant differences were observed between the groups (high and low baseline eosinophil counts) in terms of demographic data, total IgE, lung function, patient-reported outcomes, or nasal comorbidities. The Asthma Control Test score and Asthma Quality of Life Questionnaire scores were poorer in patients with FeNO ≥30 ppb than in patients with FeNO <30 ppb. In the high FeNO subgroup, more frequent hospital admissions and a higher number of working days lost in the previous year were registered. A combined score including both eosinophils and FeNO did not improve the accuracy of the individual parameters. In the high-eosinophil subgroup, the proportion of responders to omalizumab was greater and increased at each follow-up time point.
Conclusions: Our findings show that blood eosinophil count is not an unequivocal marker of asthma severity, whereas a higher FeNO level is associated with more frequent hospital admissions and more working days lost. Blood eosinophils seem to act as a predictor of response to omalizumab.
Key words: Severe asthma, Eosinophils, Omalizumab, Biomarker, TH2 inflammation, Asthma network