Patients with recalcitrant CRS should be evaluated for primary immunodeficiency. This should include as assessment of quantitative serum immunoglobulin levels as well as functional antibody responses. Medical therapy, particularly immunoglobulin replacement therapy, appears to be most effective when administered at high doses early in the disease course. The addition of surgery is less clearly supported, but may also provide benefit if performed early.

Introduction The olfactory region is capable of continuous neurogenesis. Situated on the cribriform plate and segments of the superior septum and both superior and middle turbinates, it is accessible through office-based biopsy and can be used to generate neural progenitor cells to study molecular abnormalities associated with neuropsychiatric disorders. The purpose of the study was to evaluate the efficacy of the endoscopic office olfactory biopsy from middle turbinate and superior-posterior septum to produce the neural progenitor cells. Methods Endoscopic office-based biopsy samples were collected and cultured neuronal cells derived from olfactory neuroepithelium (CNON) were established from 40 healthy individuals and 40 schizophrenia patients. All patients underwent biopsies of both the middle turbinate and the superior-posterior septum. Specific culture conditions promoted the growth of neural progenitor cells from these biopsy sites. CNON cultures were established from such outgrowing neuronal cells. The study was IRB approved and informed consent was obtained. Results Cultures were successfully developed from 98.8% of participants. No complications were observed. The single, unsuccessful specimen failed to grow any cell types due to tissue mishandling. Overall, we have observed no significant difference in the effectiveness of biopsy from middle turbinate and superior-posterior septum to produce neural progenitor cells. Conclusions The middle turbinate biopsies contain viable neural progenitor cells capable of generating neuronal cell cultures. Thus technically more simple biopsy of the middle turbinate can be used to propagate neural progenitor cells.