Pattern of Urinary Angiostatin Level in Different Class of Lupus Nephritis

Open Access

Abstract

Background: Lupus nephritis (LN) is a serious complication of systemic lupus erythematosus (SLE). Renal biopsy is invasive and associated with complications. So there is a critical need for reliable non-invasive biomarkers that can be used as supportive tool for assessment of histological class of LN. Aim of the study: This study aimed to see pattern of urinary Angiostatin level in different class of lupus nephritis. Methods & Materials: A total of 49 adult SLE with new biopsy proven class II, class III, class IV, class V and class VI lupus nephritis patients before receiving immunosuppressive therapy were enrolled into study from June 2023-November 2024. Relevant clinical (SLE score), laboratory test (CBC, CRP, S. Creatinine, U.R/M/E, 24 Hours UTP) and serological tests (ANA, Anti-dsDNA, C3 and C4) were done. Activity and chronicity index score were determined by renal biopsy. Urinary Angiostatin assay was done by using human urinary Angiostatin ELISA Kit. Result: LN histology classes were II (n=8, 16.3%), III (n= 15, 30.6%), IV(n= 17, 34.7%), V(n=5,10.2%) and VI(n=4,8.2%). Urinary Angiostatin level was 1.90±0.77 ng/ml, 14.33±2.66 ng/ml, 16.0±2.78 ng/ml, 2.92±2.28 ng/ml and 2.88±0.63 ng/ml in class II, III, IV,V and VI respectively (P value < 0.001). Class III and class IV had higher urinary Angiostatin level than other classes of lupus nephritis. Urinary angiostatin levels correlated positively with SLE score (r=+0.938), AntidsDNA (r = + 0.968), serum creatinine (r=+0.38), activity index (r=+0.957) and correlated negatively with C3(r = -0.914), C4(r = -0.761) and eGFR (r=- 0.74). Conclusion: Urinary Angiostatin level was significantly elevated in class III and class IV than other classes of lupus nephritis. It was also elevated in those patients who had higher histological activity, but not in those who had higher chronicity.