Objective: To explore the differences in severity of motor function between individuals with NT5c1A seropositive and seronegative inclusion body myositis (IBM).
Background: IBM is a subtype of the idiopathic inflammatory myopathies characterized by muscle weakness and inflammation afflicting patients over the age of 40 years. Anti-NT5c1A antibodies are common in patients with IBM, thus becoming a novel biomarker for diagnosis; however, there is still conflicting data investigating the differences in the characteristics of motor function severity and serological antibody status in IBM patients. A few studies suggest that NT5c1A seropositivity may prognosticate a more severe IBM phenotype, furthering the motivation to examine anti-NT5c1A antibodies and their hypothesized relationship to motor function severity.
Methods: INSPIRE-IBM is a prospective natural history study involving 150 participants from a consortium of thirteen myositis treatment centers across the United States. Eligibility includes individuals who fulfill the ENMC 2011 IBM criteria with disease onset within 10 years of the time of Baseline visit. Functional assessments evaluated include: Manual Muscle Testing (MMT) and Timed get up-and-go (TUG). Medical Research Council (MRC) sum scores will be analyzed to relate antibody status to functional results.
Results/Conclusion: The data will be analyzed in January 2024 when enrollment is closed and all participants have completed their Baseline visit. Results from the Baseline visit will be presented.