Introduction
Subglottic stenosis (SGS) is a rare narrowing of the airway below the vocal folds and above the first two tracheal rings. It usually can be classified as postprocedural injury, complication of autoimmune illness, or idiopathic onset. Current literature suggests immune dysregulation is involved in all etiologies of SGS, but patterns of dysfunction remain poorly understood. Characterizing immune markers and autoimmune history in SGS patients may clarify whether idiopathic SGS reflects unrecognized immune-mediated disease.

Objective
To characterize autoimmune risk factors among SGS patients and conduct exploratory comparisons between patients with and without positive immune markers.

Methods
We performed a retrospective chart review of SGS patients treated at a quaternary care office between January 2010 and April 2024. Patients were categorized as idiopathic, autoimmune, or postprocedural SGS using clinical history and videostroboscopy. Data collected included basic immune testing (CRP, ANA, RF, immunoglobulins) and personal/family autoimmune history. Patients were classified as “immune test positive” if one or more markers were abnormal.

Results
Of 29 patients reviewed to date, 3 (10.3%) demonstrated positive immune markers: 2 with postprocedural SGS and 1 with idiopathic SGS. The need for revision surgery was common in both groups: 2 of 3 (67%) immune-positive and 19 of 26 (73%) immune-negative patients required additional procedures, with similar average revision counts (5.5 vs. 6.6).

Conclusion
Immune marker positivity was observed across both idiopathic and postprocedural etiologies, suggesting that immune dysregulation may contribute beyond overt autoimmune SGS. These preliminary findings indicate that basic immune marker positivity does not strongly predict revision surgery frequency but may signal shared inflammatory mechanisms across SGS subtypes.