S100A8 in Serum and Urine as a New Biomarker in Lupus Nephritis

Completed

• Conditions: S100A8; Serum; Urine; Biomarker; Lupus; Nephritis

• Registration Number: NCT06872138
• Lead Sponsor: Theodor Bilharz Research Institute

Brief Summary

This study aims to evaluate both serum and urine S100A8 as potential biomarkers for Lupus nephritis (LN)

Detailed Description

Systemic lupus erythematosus (SLE) is a systemic autoimmune/ inflammatory disease that can affect any organ of the human body. The molecular pathophysiology of SLE remains largely unknown, but complex interactions of genetic factors, the environment, and hormones contribute to disease expression.

Clinical importance of S100 calcium-binding protein A8 protein (S100A8) as a biomarker in SLE has been well-established. During an inflammatory reaction, neutrophils produce S100A8, a Ca2+-binding protein that is part of the S100 family and is found in neutrophil extracellular traps.

In addition to its primary role as a member of the S100A8/A9 heterodimer, S100A8 accumulates in various bodily compartments and functions as a damage-associated molecular pattern molecule upon release. It is a crucial regulator of inflammation and enhances the function of innate immune cells by interacting with members of the immunoglobulin superfamily of cell surface molecules, such as toll-like receptor 4 and the receptor of advanced glycation end products.

Serum S100A8 levels are linked with disease activity, glomerulonephritis, and anti-double-stranded DNA (dsDNA) antibodies (Ab), according to increasing experimental and clinical data. healthy controls (HCs) had lower serum S100A8 levels. Considering that elevated blood S100A8 levels are also seen in several inflammatory disorders such as inflammatory bowel disease and rheumatoid arthritis, it is unclear if this elevated level is adequate to serve as a biomarker specific to SLE.

Study Timeline

• Study Start: 2024-11-01
• Study First Submitted: 2025-03-06
• Study First Submitted QC: 2025-03-06
• Study First Posted: 2025-03-12
• Primary Completion: 2025-03-30
• Study Completion: 2025-03-30
• Status Verified: 2025-05
• Last Update Submitted: 2025-05-18
• Last Update Posted: 2025-05-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 70

Inclusion Criteria

• Age ≥ 18 years.
• Both sexes.
• Patients with Systemic lupus erythematosus (SLE)
• Patients with SLE and renal affection. SLE diagnosis is based on the 1997 American College of Rheumatology (ACR) criteria or the 2012 Systemic Lupus International Collaborating Clinics (SLICC) classification criteria.

Renal involvement (lupus Nephritis) (LN) can be diagnosed by presence of proteinurea or elevated kidney function and can be confirmed by biopsy if present.

Exclusion Criteria

• Autoimmune diseases.
• Sjogren's syndrome.
• Rheumatoid arthritis.
• Systemic sclerosis.
• Taking other biologic disease-modifying anti-rheumatic drugs.
• Immunosuppressive drugs.
• Corticosteroid.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Assessment of S100A8 levels in serum for diagnosing lupus nephritis (LN)	3 months	Venous blood (5cm blood) and urine will be collected from patients with systemic lupus erythematosus (SLE) and healthy control, and the serum will be immediately centrifuged at 15,928 relative centrifugal force (RCF) and for 10 min. The supernatant will be collected and stored at -80°C until further analysis.; Before the enzyme-linked immunosorbent assay (ELISA) is conducted, frozen serum samples will be thawed and then diluted 1:100 in phosphate-buffered saline. S100A8 homodimer concentrations will be measured using a commercially available ELISA kit for serum.

Secondary Outcome Measures

Name	Time	Method
Accessment S100A8 levels in urine for diagnosing lupus nephritis (LN)	3 months	Venous blood (5cm blood) and urine will be collected from patients with systemic lupus erythematosus (SLE) and healthy control, and the serum will be immediately centrifuged at 15,928 relative centrifugal force (RCF) and for 10 min. The supernatant will be collected and stored at -80°C until further analysis.; Before the enzyme-linked immunosorbent assay (ELISA) is conducted, frozen urine samples will be thawed and then diluted 1:100 in phosphate-buffered saline. S100A8 homodimer concentrations will be measured using a commercially available ELISA kit for urine.
Correlation between S100A8 level and disease activity markers	3 months	Correlation between S100A8 level and disease activity markers in patients with systemic lupus erythematosus will be measured
Using S100A8 as a predictor for renal affection in systemic lupus erythematosus (SLE) patients for follow up and early treatment.	3 months	Renal involvement lupus Nephritis can be diagnosed by presence of proteinurea or elevated kidney function and can be confirmed by biopsy if present.

Trial Locations

Locations (1)

Theodor Bilharz Research Institute; 🇪🇬 Giza, Egypt