Blood eosinophilic and basophilic trends in recurring and non-recurring eosinophilic rhinosinusitis with nasal polyps

Background: Very few studies have compared blood eosinophil and basophil levels before and after surgery in patients with eosinophilic CRSwNP (eCRSwNP). No investigations seem to have repeatedly measured them pre- and postoperatively in eCRSwNP patients with recurring versus non-recurring disease to examine how their levels evolved. Objective: Hence this study to analyze blood eosinophil and basophil levels in patients with eCRSwNP immediately before surgery and afterwards, at 4months, 1 year, and then yearly up to 5 years. Methods: Fifty-one eCRSwNP patients were enrolled, who all had preoperative laboratory data and the results of at least 4 of the 6 scheduled postoperative follow-up tests. Results: Seventeen patients had recurrent disease. Blood eosinophil counts (p¼0.005) and percentages (p¼0.002) were both higher in these patients than in those whose eCRSwNPs did not recur after surgery. Blood basophil counts (p¼0.04) and percentages (p<0.05) were also significantly higher in patients whose eCRSwNPs relapsed. The time by relapse interaction was not significant for either counts or percentages, though an effect of time was detected for basophil counts (p¼0.01). Conclusions: In eCRSwNP, the statistical analysis of repeated quantitative laboratory data can shed light on the evolution of a patient’s systemic inflammatory picture in response to previous treatments, and above all to long-term therapies. Longterm monitoring of blood eosinophil and basophil levels could be of significant value when monoclonal antibodies that inhibit IL signaling will widely enter in clinical practice for eCRSwNP treatment to follow the effectiveness of therapy over time.