Defining Clinical Subgroups in Relapsing Polychondritis: A Prospective Observational Cohort Study

Area of Science:

• Rheumatology
• Immunology
• Systemic Autoimmune Diseases

Background:

• Relapsing polychondritis (RP) is a rare systemic inflammatory disorder affecting cartilaginous structures.
• Delayed diagnosis of RP can lead to severe complications and increased mortality.
• Identifying distinct clinical patterns is crucial for understanding RP heterogeneity.

Purpose of the Study:

• To identify and characterize distinct clinical subgroups within a prospective cohort of patients with relapsing polychondritis.
• To analyze the clinical variables associated with each identified subgroup.
• To correlate subgroup characteristics with diagnostic timelines and disease-related complications.

Main Methods:

• Latent class analysis was employed to classify patients into subgroups based on eight key clinical variables.
• Variables included saddle-nose deformity, subglottic stenosis, tracheomalacia, bronchomalacia, ear chondritis, tenosynovitis/synovitis, inflammatory eye disease, and audiovestibular disease.
• Akaike's information criterion was used for model selection.

Main Results:

• Three distinct subgroups of relapsing polychondritis (RP) were identified: Type 1 (14%), Type 2 (29%), and Type 3 (58%).
• Type 1 RP showed high rates of ear chondritis, tracheomalacia, saddle-nose deformity, and subglottic stenosis, with the shortest diagnostic time (1 year).
• Type 2 RP featured tracheomalacia and bronchomalacia, with the longest diagnostic time (10 years) and highest work disability. Type 3 RP was characterized by tenosynovitis/synovitis and ear chondritis.

Conclusions:

• Relapsing polychondritis manifests in at least three distinct clinical subgroups with varying characteristics and complications.
• Differences in clinical presentation influence the time to diagnosis and disease severity.
• A broader recognition of RP's clinical spectrum beyond typical cartilaginous involvement is essential for earlier diagnosis and improved management.