IL-33 in Spondyloarthritis, the missing key.

Area of Science:

• Immunology
• Rheumatology
• Pathophysiology

Background:

• Interleukin-33 (IL-33) is an alarmin released during tissue damage, increasingly linked to inflammatory diseases like spondyloarthritis (SpA).
• The IL-33/ST2 pathway influences immune cell activation, including type 2 innate lymphoid cells, Th17 responses, and macrophage polarization, contributing to SpA pathogenesis.
• IL-33 plays a role in both musculoskeletal (enthesitis, synovitis, axial inflammation) and extra-articular (gut, skin, eye) manifestations of SpA.

Purpose of the Study:

• To review the emerging role of the IL-33/ST2 pathway in the pathophysiology of spondyloarthritis.
• To discuss the therapeutic potential of targeting IL-33 for SpA treatment, including its impact on inflammation and bone metabolism.

Main Methods:

• Review of preclinical studies and existing literature on the IL-33/ST2 axis in spondyloarthritis.
• Analysis of IL-33's dual role in inflammation and bone metabolism within the context of SpA.

Main Results:

• Preclinical studies targeting the IL-33/ST2 axis demonstrate reduced arthritis severity, joint damage, and inflammation.
• IL-33 exhibits a dual role, potentially inhibiting osteoclast differentiation or promoting pathological bone formation via pro-osteogenic macrophages.
• IL-33 modulation offers a potential strategy to control inflammation and influence structural outcomes, including new bone formation in SpA.

Conclusions:

• The IL-33/ST2 pathway is a significant factor in SpA development and progression.
• Targeting IL-33 presents a promising therapeutic avenue, potentially complementing existing treatments like anti-TNFα and anti-IL-17 therapies.
• Modulating IL-33 could offer a dual benefit in SpA by reducing inflammation and altering bone remodeling processes.