265. Isolated subglottic stenosis secondary to GPA: a descriptive cohort study
Creators: name: Rishana Shuaib1
name: Benshetrit1, Guy
name: Prendecki1, Maria
name: Kuchai1, Romana
name: Ivor Kwame1,
Publisher: name: Zenodo
Year: 2022
Subjects: Vasculitis
ANCA
Abstracts
Giant Cell Arthritis
MPA
GPA
EGPA
Takayasu
IgA vasculitis

description: <strong>Background:</strong> Subglottic stenosis (SGS) is a common manifestation of granulomatosis with polyangiitis (GPA) and is defined as narrowing of the airway immediately below the vocal cords. Symptoms include stridor, hoarse voice, and dyspnoea, and may be severe enough to require tracheostomy. Distinguishing ‘idiopathic’ SGS from ‘limited’ forms of GPA is challenging, and the role of immunosuppressive therapy is unclear. <strong>Methods:</strong> We undertook a retrospective analysis of patients presenting to a single tertiary unit with SGS between 2008 and 2020, and identified those where SGS was an isolated or predominant feature of GPA. Patients were distinguished from ‘idiopathic SGS’ and defined as ‘GPA-SGS’ if they had endoscopic evidence of SGS and (i) positive serologic testing for ANCA (by indirect immunofluorescence or antigen-specific assay), and/or (ii) an airway biopsy showing histologic features compatible with GPA (vasculitis, granulomatous inflammation), and/or (iii) they manifested additional features of upper airway GPA (laryngotracheal involvement, septal perforation, sinonasal involvement, nasolacrimal involvement, recurrent otitis media). <strong>Results:</strong> We identified 29 patients with GPA-SGS. 69% (n=20) patients were female and the median age at presentation was 46 years (range 16-87) years. The main symptom at presentation was dyspnoea, associated with stridor in 52% (n=15) patients, wheeze in 25% (n=7) and cough in 7% (n=2). Other clinical features included dyspnonia (n=4 ), epistaxis (n=3), and chronic rhinitis (n=1). The median time for diagnosis from symptom onset was 38.4 months. On bronchoscopy, all had SGS and 28% (n=8) patients had evidence of further tracheal stenosis and 3% (n=1) individual had glottic stenosis. 86% (n=25) patients underwent airway biopsies; these showed active chronic inflammation in all cases, with confirmatory features of <em>vasculitis</em> in 3 and granulomatous inflammation in 4. 66% (n=19) had positive ANCA serology: 6 patients had a positive cANCA by IIF (of whom 4 had detectable PR3-ANCA); 13 were pANCA positive by IIF (of whom 4 had detectable MPO-ANCA). 93% (n=27) patients required airway intervention via microlaryngoscopy, and 17% (n=5) needed more complex interventions in the form of laryngotracheal reconstruction. 76% (n=22) patients were treated with systemic immunosuppression. In patients not immunosuppressed this was due to risk of infection (n=3), frailty (n=3), mild symptoms (n=1). In patients who were immunosuppressed, first line treatments were azathioprine (n=10), cyclophosphamide (n=3), MMF (n=2), MTX (n=2), rituximab (n=2) and prednisolone alone (n=3), although choice of immunosuppression varied during follow up. Immunosuppressive treatment was associated with fewer surgical interventions: the average frequency of intervention was 1 procedure per 32.4 months follow-up during periods of immunosuppressive treatment and 1 procedure per 13.4 months during periods of non-treatment. <strong>Conclusions:</strong> GPA-SGS shares many features of ‘idiopathic’ SGS, including female preponderance, age of onset, and potential for very delayed diagnosis. Patients with GPA-SGS often present with severe and life-threatening manifestations. Our experience suggests that immunosuppression may be associated with reduced need for airway interventions in GPA-SGS, though more work is needed to understand the value of specific treatments and the influence of confounding associations in more detail. <strong>Disclosures:</strong> None