Objective: To determine the levels of urinary soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cellular adhesion molecule-1 (VCAM-1) in patients with lupus nephritis (LN), and explore their correlation with renal disease activity.
Methods: Urine samples were collected from 92 renal biopsy-proven LN patients and 20 healthy controls. Renal disease activity was determined according to the ISN/RPS 2003 Revised Classification of Lupus Nephritis. The urine levels of sICAM-1 and VCAM-1 were detected by enzyme-linked immunosorbent assay, and the expressions of intrarenal ICAM-1 and VCAM-1 were evaluated by immunohistochemisty staining.
Results: Urinary sICAM-1 and VCAM-1 levels were elevated in LN patients compared with the controls. Significantly higher levels of urinary sICAM-1 and VCAM-1 were found in patients with active LN, who had also significantly increased intrarenal expressions of ICAM-1 and VCAM-1 compared with patients in remission. A strong positive correlation was noted between intrarenal expression and urine levels of ICAM-1 and VCAM-1. The receiver-operating characteristic (ROC) curve of urine sICAM-1 showed tan area under ROC curve of 0.874 for all participants in the test. A cutoff of 1095.00 pg/mg creatinine yielded a good sensitivity (0.945) and specificity (0.789). The ROC curve of urine VCAM-1 showed an area under ROC of 0.882 for all the participants, and a cutoff of 898.11 pg/mg creatinine yielded a good sensitivity (0.982) and specificity (0.667).
Conclusion: Urine sICAM-1 and VCAM-1 levels are positively correlated with their intrarenal expressions and reflect the activity of the nephritis, and therefore they may serve as potential biomarkers for early diagnosis of active LN.