Association of Serum Interleukin-33 Levels With Clinical Manifestations in Systemic Lupus Erythematosus

Serum Interleukin-33 (IL-33) Levels and Their Association With Clinical Manifestations in Patients With Systemic Lupus Erythematosus and Lupus Nephritis at Assiut University Hospital

This is a case-control study investigating serum IL-33 levels and their association with clinical manifestations in systemic lupus erythematosus (SLE). The study compares IL-33 levels in three groups: SLE patients with lupus nephritis, SLE patients without nephritis, and healthy controls. The goal is to clarify IL-33's role as a biomarker reflecting disease activity and organ involvement, especially renal pathology.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with variable clinical presentations, ranging from mild symptoms to life-threatening organ damage. Lupus nephritis, a severe renal manifestation of SLE, significantly contributes to morbidity and mortality. IL-33, a cytokine from the IL-1 family, has been implicated in immune regulation and inflammation, emerging as a potential marker in SLE pathogenesis and progression.

This study systematically evaluates serum IL-33 levels in 96 participants divided into three groups: SLE patients with lupus nephritis, SLE patients without nephritis, and matched healthy controls. The study is conducted over one year at the Rheumatology Department of Assiut University Hospital. It includes clinical assessments, laboratory investigations (including ELISA for IL-33, autoantibody profiles, renal function), renal Doppler ultrasound for nephritis patients, and renal biopsy analyzed using ISN/RPS classification.

By assessing IL-33 levels alongside clinical manifestations, disease activity indices, and histopathological findings, the study aims to define IL-33's diagnostic and prognostic utility in lupus nephritis and overall SLE disease monitoring. Statistical analysis with SPSS includes ANOVA and correlation tests to detect differences and associations.

Inclusion Criteria:

• Adults aged 18 years and older.
• Diagnosed with systemic lupus erythematosus according to the American College of Rheumatology (ACR) criteria.
• For the lupus nephritis group: confirmed diagnosis of lupus nephritis based on clinical, laboratory, and renal biopsy findings.
• For the control group: healthy individuals matched for age and sex, with no history of autoimmune or renal diseases.

Exclusion Criteria:

• Patients with other autoimmune diseases. Patients with chronic infections or malignancies. Pregnant or lactating women. Patients with end-stage renal disease (ESRD) or on dialysis. Individuals who refuse to provide informed consent.