title: Higher antineutrophil cytoplasmic antibody (C-ANCA) titers are associated with increased overall healthcare use in patients with sinonasal manifestations of granulomatosis with polyangiitis (GPA).
abstract: BACKGROUND
  Granulomatosis with polyangiitis (GPA) is an autoimmune disease characterized by necrotizing granulomatous airway inflammation and vasculitis. Sinonasal involvement occurs in more than 80% cases, with antineutrophil cytoplasmic antibody (C-ANCA) titers used as a marker of disease severity. The purpose of this study was to determine whether C-ANCA levels impact radiographic findings and healthcare use in patients with sinonasal GPA.
  
  
  METHODS
  A retrospective review was performed on GPA patients evaluated in a multidisciplinary rheumatologic/otolaryngologic clinic from 2008 to 2013. Data were collected with respect to age, gender, clinical presentation, C-ANCA titers, Lund-Mackay (LM) scores, surgical interventions, and healthcare use, the latter of which were determined by assessing the number of rheumatology/otolaryngology clinic visits, computed tomography (CT) scans, and email/telephone encounters.
  
  
  RESULTS
  A total of 44 patients were identified, 11 male and 33 female. Sinonasal manifestations were evident in 70.4%, with chronic rhinosinusitis (CRS) (41.9%), septal perforation (38.7%), and crusting (32.2%) the most common findings. No significant differences in number of CT scans (p = 0.10) or mean LM scores (p = 0.47) were found between patients with more than or equal to 1:80 and less than 1:80 C-ANCA titers, respectively. However, overall healthcare use was increased in the more than or equal to 1:80 C-ANCA group (n = 28) compared with less than 1:80 (n = 16), with a significantly greater number of rheumatologic/otolaryngologic encounters (mean 121 versus 69.2, p = 0.03) noted. When otolaryngologic healthcare use was specifically examined, the average number of encounters was also higher in more than or equal to 1:80 C-ANCA patients (31.9 versus 22.9), but this difference was not statistically significant (p = 0.16).
  
  
  CONCLUSIONS
  Sinonasal GPA patients with presenting C-ANCA titers more than or equal to 1:80 demonstrated significantly greater overall healthcare use than their lower C-ANCA level counterparts (less than 1:80). However, no significant differences in otolaryngology resource use or LM scores were evident between the two titer groups.
authors.affiliation: Orange County Sinus Institute, Southern California Permanente Medical Group, Irvine, California, USA.
authors.forename: Agnieszka M
authors.initials: AM
authors.lastname: Janisiewicz
authors.forename: Marc H
authors.initials: MH
authors.lastname: Klau
authors.forename: David B
authors.initials: DB
authors.lastname: Keschner
authors.forename: Randy R
authors.initials: RR
authors.lastname: Lehmer
authors.forename: Kumar V
authors.initials: KV
authors.lastname: Venkat
authors.forename: Swati S
authors.initials: SS
authors.lastname: Medhekar
authors.forename: Parke K
authors.initials: PK
authors.lastname: Chang
authors.forename: Karam
authors.initials: K
authors.lastname: Badran
authors.forename: Ryan
authors.initials: R
authors.lastname: Leary
authors.forename: Rohit
authors.initials: R
authors.lastname: Garg
authors.forename: Andrew A
authors.initials: AA
authors.lastname: Nguyen
authors.forename: Jivianne T
authors.initials: JT
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis*; D005260:Female; D014890:Granulomatosis with Polyangiitis / Q000150:complications* / Q000276:immunology*; D006296:Health Services / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic