This is a cross-sectional study of up to 100 subjects who are undergoing clinically indicated sinus procedures to treat chronic rhinosinusitis. Participants will be asked to donate leftover sino-nasal secretions, sino-nasal tissue and blood as well as undergo partial characterization. As optional extensions of the main study, participants may also undergo a biopsy of extra sino-nasal tissue for additional tissue analysis and/or a more detailed characterization visit performed in the UCSF Airway Center Research Center (ACRC).

This is a cross-sectional study of up to 100 participants who are undergoing clinically indicated sinus procedures to treat chronic rhinosinusitis. 50 participants with CRSwNP and 50 participants with CRS without polyps and no features of atopy will be enrolled in the study. Participants will donate leftover sino-nasal secretions and tissue from their procedures. In addition, participants will be subject to medical record review and research questionnaires.

In many instances, these participants will have multiple procedures over time to treat recurrent disease and this study will allow for them to donate leftover biospecimens as many as 9 times.

Participants may also opt to undergo a turbinate mucosal tissue biopsy during regularly scheduled sinus surgery for additional tissue analysis and/or undergo a more detailed, complete characterization visit performed in the UCSF Airway Center Research Center (ACRC). During the complete characterization, participants will undergo lung function tests, sputum induction and blood collection, in addition to the procedures mentioned above.

Participants with Chronic Rhinosinusitus with Nasal Polyps

Inclusion Criteria:

• Males or females between the ages 18 to 80 (inclusive).
• History of blood eosinophils > 200 cells/dL (or tissue eosinophilia evident on histopathologic review of sino-nasal tissues).
• Physician diagnosis of chronic rhinosinusitis (CRS).
• Undergoing office-based or operating room-based sinus procedures for a clinical indication.
• Written informed consent obtained from subject and ability for subject to comply with the requirements of the study.

Exclusion Criteria:

• Smoking of tobacco or other recreational inhalants more than twice in the last month and/or >10 pack-year smoking history.
• History of cystic fibrosis or ciliary dyskinesia.
• Currently taking immunosuppressant drugs including Mycophenolate mofetil (Cellcept), Cyclophosphamide (Cytoxan), Azathioprine (Imuran).

Participants with Chronic Rhinosinusitus without Nasal Polyps

Inclusion Criteria:

• Males or females between the ages 18 to 80 (inclusive)
• Physician diagnosis of CRS.
• Undergoing office-based or operating room-based sinus procedures for a clinical indication.
• Written informed consent obtained from subject and ability for subject to comply with the requirements of the study.

Exclusion Criteria:

• Smoking of tobacco or other recreational inhalants more than twice in the last month and/or >10 pack-year smoking history.
• Presence of nasal polyps.
• History of allergic rhinitis.
• History of blood eosinophilia > 200 (or tissue eosinophilia evident on histopathologic review of sino-nasal tissues).
• Currently taking immunosuppressant drugs including Mycophenolate mofetil (Cellcept), Cyclophosphamide (Cytoxan), Azathioprine (Imuran).

Participants with chronic rhinosinusitis who present with or without nasal polyps between the ages of 18 and 80 years.