16PComparative evaluation of respiratory assessments in inclusion body myositis from INSPIRE-IBM study

Inclusion body myositis (IBM) is the most common acquired muscle disease in individuals over 40, characterized by progressive, asymmetric muscle weakness that impairs mobility and daily functioning. Respiratory failure is a frequent complication. Previous studies in small IBM cohorts have shown that seropositivity for NT5c1A antibodies is associated with significantly reduced pulmonary function, particularly in maximum inspiratory pressure (MIP) and forced vital capacity (FVC), suggesting more severe respiratory involvement. However, larger-scale studies are needed to confirm this relationship. The ongoing INSPIRE-IBM study is a multicenter, prospective observational study involving 150 IBM patients across 13 sites. We analyzed pulmonary function data collected at baseline, 12 months, and 18 months, including sitting and supine FVC, MIP, and maximum expiratory pressure (MEP) to examine correlations with NT5c1A seropositivity. Additionally, correlations with NIH PROMIS (Sleep) were collected. Data analysis is currently underway and will be presented at the upcoming conference. Based on earlier findings, we anticipate that NT5c1A-seropositive participants will again demonstrate lower pulmonary function test results, providing greater evidence of respiratory involvement in this subgroup.