The association between urinary angiostatin and urinary angiostatin to urinary creatinine ratio with lupus nephritis and their correlation to disease activity

Background. Currently, renal biopsy is the gold standard tool for diagnosis and prediction of prognosis in lupus nephritis (LN). However it cannot be performed serially and tissue obtained may not represent the renal pathology. Finding a non-invasive, easily obtainable, and accurate marker that performed serially may therefore be of greater value in monitoring LN. Aim of study. To explore the ability of urinary angiostatin and urinary angiostatin / urinary creatinine (UAng/UCr) ratio to identify SLE with nephritis and their relation with lupus activity. Subjects and Methods.UAng and UAng/UCr ratio were evaluated in 100 lupus patients and compared to that in the controls. These markers were also compared between patients with and without LN. Results. UAng and Ln UAng/UCr ratio were significantly higher in SLE patients than controls and also in SLE patients with than without LN.Among SLEpatients,these markers are significantly correlated with SLEDAI score and with serum creatinine while inversely correlated with serum C3 and C4 levels. Among LN patients, UAng and Ln UAng/UCr ratio are significantly correlated with renal SLEDAI score and renal chronicity index but not with renal activity index. A ROC curve analysis revealed the usefulness of UAng and Ln Uang/UCr ratio in discriminating SLE patients with LN from those without LN. Conclusion. UAng and Ln UAng/UCr ratio are associated with LN class and renal chronicity index .UAng and Ln UAng/UCr ratio are capable of identifying lupus patients with LN from patients without. UAng and Ln UAng/UCr ratio are correlated with lupus activity.