(1229) Serum Eosinophilia Suggests Differences in Chronic Rhinosinusitis with Nasal Polyps Between the Gulf Region and Canada

Introduction: Chronic Rhinosinusitis with Nasal Polyposis (CRSwNP) is a global disease with a tendency to recur. Differences between disease endotypes has been described for several Asian countries, with a reported trend to lower presence of Type 2 disease in certain Asian CRSwNP populations (Bachert JACI). However, the Gulf region of the Arabian Peninsula differs in terms of genetic background and environmental conditions from the Americas and Europe. Anecdotal reports have described severe, recalcitrant disease in Gulf area CRSwNP patients. As higher levels of serum eosinophilia predict more severe asthma and CRSwNP disease, it is possible that this is secondary to an over-representation of Type 2 disease in the Gulf population, however this remains speculative, as little information exists on the prevalence of Type 2 markers in the CRSwNP. We aimed to verify whether serum biomarkers of Type 2 disease were similar in CRSwNP in Gulf and Canadian CRSwNP patients.

Methods: Serum eosinophilia was collected from 88 Gulf patients with newly diagnosed CRSwNP from a governmental tertiary center in Dubai, United Arab Emirates. The data was then compared with two Canadian populations with CRSwNP previously phenotyped for population association genetic studies. (GCRS1: Recurrent CRSwNP, n=198; GCRS2: Any CRSwNP, n=467).

Results: Average serum eosinophilia was similar in the UAE (0.35) and GCRS1 groups (0.33) but was slightly higher in the GCRS2 “any polyp” group (0.44) (p=0.05). The percentage of subjects with serum eosinophilia values of more than 300 was found to be (39.1%) in the UAE population. In contrast, the GCRS1 group showed a percentage of (50%), and a higher level was seen in the GCRS2 “any polyp” group (61%) (p=0.05).

Conclusions: In conclusion, Gulf CRSwNP disease resembles CRSwNP in North America from an immunologic standpoint. As such, management strategies developed and used in other countries including North America can be used in the Gulf region.