OBJECTIVETo study feasibility of Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2000) and British Isles Lupus Assessment Group 2004 (BILAG-2004) scoring systems for assessing renal disease activity in children with lupus nephritis (LN).

METHODSThe clinical data of 159 children with systemic lupus erythematosus (SLE) and LN were collected, and disease activity was assessed by SLEDAI-2000 and BILAG-2004 scoring systems. The correlations between SLEDAI-2000 and BILAG-2004 scores and 24-hour urinary protein excretion and renal pathology index were analyzed. The SLEDAI-2000 and BILAG-2004 scoring systems were evaluated using ROC curve.

RESULTSApproximately one third (31.5%) of the 159 children had a moderate level of 24-hour urinary protein excretion. Among the 37 patients undergoing renal biopsy, 46.0% had diffuse LN (type Ⅳ). 24-hour urinary protein excretion was positively correlated with both SLEDAI-2000 (r=0.36, P<0.05) and BILAG-2004 scores (r= 0.39, P<0.05). Children with types Ⅰ, Ⅱ, Ⅲ, and Ⅳ LN had pathology activity index (AI) which positively correlated with SLEDAI-2000 scores (r=0.86, 0.88, 0.84, 0.77 respectively; P<0.05) and BILAG-2004 scores (r= 0.88, 0.98, 0.86, 0.89 respectively; P<0.05). SLEDAI-2000 score showed the best correlation with AI in patients with type Ⅱ LN, followed by those with type Ⅰ LN. BIILAG-2004 score showed the best correlation with AI in patients with type Ⅱ LN, followed by those with type Ⅳ LN. The BILAG-2004 scoring system had an area under the ROC curve (AUC) of 0.93, and the SLEDAI-2000 scoring system had an AUC of 0.88.

CONCLUSIONSBILAG-2004 and SLEDAI-2000 scoring systems can be used to assess renal disease activity of patients with LN. The BILAG-2004 scoring system can provide more reliable and comprehensive assessment.