Understanding the Propensity for Chronic Sinusitis in Patients on Immunosuppressive Therapy.

Background Chronic rhinosinusitis (CRS) is a frequently observed condition in patients with immunodeficiency secondary to immunosuppressive medications. The histologic features of CRS among patients undergoing immunosuppressive treatment have yet to be determined and may have important implications on understanding the pathophysiology of the disease process. Methods A structured histopathology report was utilized to analyze sinus tissue removed during functional endoscopic sinus surgery (FESS). Histopathology variables, Lund-Mackay score (LMS), and sinonasal outcome test 22 scores were compared among patients with CRS on immunosuppressive therapy (CRSi), CRS without nasal polyps (CRSsNP) patients, and CRS with nasal polyps (CRSwNP) patients. Results Fifteen CRSi, 36 CRSwNP, and 56 CRSsNP patients undergoing FESS were analyzed. Compared to CRSsNP, CRSi patients exhibited a trend toward increased moderate-severe inflammation (66.7% vs 42.1%, P < .080), increased neutrophil infiltrate (40.0% vs 24.6%, P < .192), and decreased fibrosis (26.7% vs 43.9%, P < .182). Compared to CRSwNP, CRSi patients demonstrated decreased fibrosis (26.7% vs 66.7%, P < .010), decreased eosinophil aggregates (13.3% vs 44.4%, P < .032), and a trend toward fewer eosinophils per high-power field (46.7% vs 66.7%, P < .154). CRSi cases had significantly lower mean LMS (8.20 ± 4.30 vs 12.78 ± 6.56, P < .017) compared to CRSwNP. Conclusion CRSi patients exhibit histopathology and disease severity more similar to CRSsNP with trends toward increased neutrophilia and reduced fibrosis. In the appropriate clinical context, discontinuing or changing a patient's immunosuppressive regimen may be a valid treatment option in patients with CRSi. This study provides initial insight into understanding the propensity for chronic sinusitis in patients undergoing immunosuppressive treatment which may have implications on disease management.