Correlation between Peripheral Blood Eosinophilia and the Histopathological Changes in Nasal Mucosal in Chronic Rhinosinusitis

Background: Chronic rhinosinusitis(CRS) has emerged as one of the major causes of significant morbidity in otorhinolaryngology, as it is often noted to be refractory to medical management and has a tendency to recur post-surgery. Limited research has shown that peripheral eosinophilia is related to the presence of nasal polyps, the extent of the mucosal disease, the severity of tissue eosinophilia, and the risk of recurrence.

Aim: This study aimed to establish the significance of peripheral blood eosinophilia, both differential (EC) and absolute eosinophil counts (AEC) - in adult CRS, to correlate the tissue eosinophilia and peripheral blood eosinophilia, and compare the observations in the two types of CRS with nasal polyp and without nasal polyp.

Material and Methods: A total of 50 adult patients with CRS who underwent FESS were included in the study and were divided based on the presence (Group 1) or absence (Group 2) of peripheral blood eosinophilia.

Results: There were equal number of cases of chronic rhinosinusitis with nasal polyp (CRSwNP) and without polyp (CRSsNP); 25 each. With regard to clinical features, Group 1 had a higher number of cases with nasal obstruction (p-value = 0.023), post-nasal drip (p-value = 0.035), and hyposmia (p-value = 0.021) when compared to Group 2. On histopathology, Group 1 had more areas of edema (p-value = 0.027), and mucous gland hyperplasia (p-value = 0.013) while Group 2 had prominent lymphoplasmacytic infiltrates (p-value = 0.035), neutrophilia (p-value = 0.047), and tissue infiltration of macrophages (p-value = 0.027). Tissue eosinophilia was present in 32 out of the total cases; 20 (71.43%) in Group 1 and 12 (53.33%) in Group 2. The group with tissue eosinophilia had significantly higher eosinophil count (9.24 ± 4.26% vs 5.32 ± 2.9%; p-value < 0.01) as well as AEC (823.335 ± 434.357/µl vs 485.128 ± 285/µl. 907; p-value < 0.01).

Conclusion: The study demonstrated that CRS cases with tissue eosinophilia exhibit an elevated peripheral eosinophil count when compared to non-eosinophilic CRS.