An Evaluation of SPARC Protein as a Serum Biomarker of Chronic Rhinosinusitis.

Objective: Precision medicine initiatives for chronic rhinosinusitis (CRS) management suggest tailoring treatment to the patient's individual disease profile; however, serum biomarkers for evaluation of disease activity or predicting response to therapy are lacking in CRS. Epithelial-to-mesenchymal transition (EMT) has been described as a component of barrier dysfunction in CRS. SPARC (secreted protein acidic and rich in cysteine) is a marker of EMT that has previously been identified in sinus epithelium by gene expression profiling.

Ménière's Disease Pathophysiology: Endolymphatic Sac Immunohistochemical Study of Aquaporin-2, V2R Vasopressin Receptor, NKCC2, and TRPV4.

Objectives Endolymphatic sac (ELS) pathophysiology in Ménière's disease (MD) remains poorly understood. We identified from the literature a group of proteins expressed on the ELS and involved in endolymph volume regulation: aquaporin-2 (AQP2), vasopressin receptor V2R, sodium potassium chloride cotransporter 2 (NKCC2), and transient receptor potential cation channel V4 (TRPV4). Our objective was to determine whether their ELS expression was altered in MD, to better understand the pathophysiology of endolymphatic hydrops.