Assessment of the Role of Urinary Heparanase in Lupus Nephritis Patients and Its Correlation with Disease Activity

Abstract

Assessing the activity of lupus nephritis (LN) with novel biomarkers is a promising noninvasive diagnostic tool for managing systemic lupus erythematosus (SLE). We assessed the ability of urinary heparanase to identify LN and its relation to the disease's activity. This crosssectional study had 90 subjects: 70 patients with SLE and 20 healthy controls. A full medical history, clinical examination, and routine investigations were carried out for the patients and controls. Immunological assays and assessments of the disease's activity with the SLE Disease Activity Index (SLEDAI) and the renal SLEDAI (r-SLEDAI) were carried out for LN groups. Urinary heparanase levels were measured using an enzyme-linked immunosorbent assay for all subjects. Of our patients, 20 had active LN, 17 had nonactive LN, 18 had active lupus without renal involvement, and 15 had nonactive lupus without renal involvement. The level of urinary heparanase was significantly higher in the LN groups than in the non-LN groups and the controls and was significantly higher in those with active LN than in those with nonactive LN. There were significant positive correlations between urinary heparanase and 24-h urinary protein, total SLEDAI, and r-SLEDAI, and significant negative correlations between urinary heparanase and Complements 3 and 4. Urinary heparanase predicted the activity of LN with a sensitivity of 80% and a specificity of 91.43%. Urinary heparanase levels were higher in patients with active LN and correlated with the markers of disease activity, indicating that it can serve as a useful new biomarker for the activity of LN.