IL-17 in cutaneous lupus erythematosus.

Area of Science:

• Immunology
• Dermatology
• Rheumatology

Background:

• Lupus erythematosus (LE) is a complex autoimmune disease with diverse clinical manifestations.
• The role of Interleukin-17 (IL-17) isoforms, specifically IL-17A and IL-17F, in the pathogenesis of LE remains incompletely understood.
• This research investigates the local and systemic expression of IL-17 in different forms of lupus skin disease.

Purpose of the Study:

• To evaluate the expression of IL-17A and IL-17F in the skin and serum of patients with discoid lupus erythematosus (DLE), systemic lupus erythematosus (SLE), and subacute cutaneous lupus erythematosus (SCLE).
• To correlate local and serological IL-17 levels with disease activity and specific autoantibodies.
• To elucidate the involvement of IL-17 isoforms in the immunopathogenesis of various lupus erythematosus subtypes.

Main Methods:

• Recruitment of 89 subjects, including patients with psoriasis, healthy controls, DLE, SLE, and SCLE.
• Collection of blood samples and skin biopsy specimens for analysis.
• Quantification of serum IL-17A, IL-17F, and IL-23 using ELISA, and assessment of skin IL-17A and CD4 expression via immunohistochemistry.

Main Results:

• Immunohistochemical analysis revealed significantly higher IL-17A expression in the skin of DLE, SCLE, and SLE patients compared to controls.
• Serum IL-17A levels were elevated in DLE and SLE patients but not in SCLE patients relative to controls.
• Serum IL-17F concentrations were significantly higher across all lupus patient groups (DLE, SCLE, SLE) compared to healthy controls, while IL-23 levels were comparable across groups.

Conclusions:

• IL-17 isoforms, IL-17A and IL-17F, are implicated in the immunopathogenesis of systemic lupus erythematosus (SLE).
• These IL-17 isoforms also play a significant role in the development of discoid lupus erythematosus (DLE) and subacute cutaneous lupus erythematosus (SCLE).
• The findings highlight IL-17 as a potential therapeutic target in various forms of lupus erythematosus.