Classical Complement Pathway Activation in the Nasal Tissue of Patients With Chronic Rhinosinusitis

Publication date: Available online 12 December 2016
Source:Journal of Allergy and Clinical Immunology
Author(s): Griet A. Van Roey, Christopher C. Vanison, Jeffanie Wu, Julia H. Huang, Lydia A. Suh, Roderick G. Carter, James E. Norton, Stephanie Shintani-Smith, David B. Conley, Kevin C. Welch, Anju T. Peters, Leslie C. Grammer, Kathleen E. Harris, Kathryn E. Hulse, Atsushi Kato, Whitney W. Stevens, Robert C. Kern, Robert P. Schleimer, Bruce K. Tan
BackgroundComplement plays a major role in inflammatory diseases but its involvement and mechanisms of activation in chronic rhinosinusitis (CRS) are not known.ObjectivesFollowing earlier studies discovering autoantibodies in CRS, we sought to investigate the nature, extent, and location of complement activation in nasal tissue of patients with CRS. Specifically, we were interested in whether antibody-mediated activation via the classical pathway was a major mechanism for complement activation in CRS.MethodsNasal tissue was obtained from patients with CRS and control patients. Tissue homogenates were analyzed for complement activation products (ELISA-C5b-9, C4d, activated C1 and C5a) and major complement fixing antibodies (Luminex). Tissue sections were stained for C5b-9, C4d, and laminin. Antibodies were purified using protein A/G columns from nasal polyps (NP), matching patient serum and control serum, and assayed for basement membrane binding via ELISA.ResultsC5b-9 was significantly increased in NP tissue compared to UT (uncinate tissue) of CRS with NP (CRSwNP) and CRS without NP (CRSsNP) (p<0.01). Similarly, C4d was increased in NP compared to UT of CRSwNP, CRSsNP and control (p<0.05). Activated C1 was also increased in NP tissue compared to UT of CRSsNP and control (p<0.05) and was correlated with C5a (p<0.01), local immunoglobulins, especially IgM (p<0.0001) and anti-dsDNA IgG (p<0.05). Immunofluorescence showed that C5b-9 and C4d deposition occurred linearly along the epithelial basement membrane. NP tissue extracts had significantly more anti-basement membrane antibodies than sera from CRSwNP and control patients (p<0.0001).ConclusionC5b-9, C4d and activated C1 were significantly increased locally in NP tissue. C5b-9 and C4d were almost universally deposited linearly along the basement membrane of NP tissue. Furthermore, activated C1 was best correlated with local immunoglobulin levels and C5a levels. Together, these data suggest that the classical pathway plays a major role in complement activation in CRS.

Teaser

Complement activation was elevated in CRSwNP tissue, and complement was deposited at the epithelial basement membrane. We conclude that the classical antibody-mediated complement pathway had a significant contribution to complement activation in nasal polyps.


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