Rethinking spondyloarthritis: beyond lumping and splitting

Area of Science:

• Rheumatology
• Immunology
• Genetics

Background:

• The classification of spondyloarthritis (SpA) has historically been debated, with ongoing discussions on lumping versus splitting subtypes.
• Traditional models often rely on clinical phenotypes, which may not fully capture disease heterogeneity.

Purpose of the Study:

• To explore the evolution of the spondyloarthritis concept.
• To discuss novel classification approaches beyond traditional models.
• To highlight the need for improved diagnostic precision and patient stratification.

Main Methods:

• Review of the evolution of the SpA concept.
• Analysis of advances in genetics, imaging, and clinical research.
• Exploration of data-driven methodologies and unbiased approaches.

Main Results:

• The SpA concept has evolved significantly since the 1970s, incorporating new research findings.
• Axial and peripheral SpA are recognized as distinct yet overlapping entities, impacting classification and drug approvals.
• Data-driven methods reveal disease heterogeneity, underscoring limitations of traditional classification.

Conclusions:

• Current SpA classification paradigms based on clinical phenotype are insufficient.
• Incorporating genetic and immunological characteristics can enhance diagnostic precision and patient outcomes.
• Future research should refine classification frameworks to improve patient stratification and treatment decisions.