Analysis of the association between the Slit2 biomarker and systemic lupus erythematosus

Abstract
Background
To assess the association between various systemic lupus erythematosus (SLE) disease manifestations, SLE disease activity index 2000 (SLEDAI-2K), systemic lupus international collaborating clinics/American College of Rheumatology Damage Index (SLICC/ACR- SDI) and serum levels of Slit2 in SLE patients.

Results
The mean age of SLE patients was 31.12 ± 8.68 years while the age at onset was 26.05 ± 7.60 years. Female: male was 9 vs 1. The mean serum levels of Slit2 in SLE patients were significantly higher than the controls (0.55 ± 0.25 vs 0.42 ± 0.15) (P = 0.013). There was no significant difference in Slit2 levels between patients with active vs inactive SLE (P = 0.353) or between patients with and without lupus nephritis (P = 0.900). An insignificant difference in Slit2 levels was found among SLE patients using SDI (P = 0.982). No significant correlations were observed between the serum Slit2 and SLE patients’ demographics, laboratory data, SLEDAI-2K, and SDI except for a positive correlation with platelets and a negative correlation with serum albumin. ROC curve analysis showed that at a cutoff value of 0.44, the area under the curve was 0.677 (95% CI 0.538–0.816, P = 0.013) with a sensitivity of 74%, specificity of 56%, and accuracy of 68%.

Conclusion
While we observed elevated serum Slit2 levels in SLE patients, there was no significant correlation observed between serum Slit2 levels and SLE clinical manifestations, disease activity, or damage index.

Trial registration
NCT05105217. Registered 3 November 2021