+LN n=30 (%) -LN n=72 (%)
Female no (%) 25 (83) 63(88)
Age at SLE diagnosis 27.5 37
Disease duration at study 12 10
Age at LN 27.5  
Renal biopsy performed 17 (59)  
Years between LN and biopsy 2  
Biopsy findings:    
   Activity Index 7  
   Chronicity Index 2  
   LN Class II 2  
   LN Class III 5  
   LN Class IV 7  
   LN Class V 2  
   LN Class VI 1  
LN; Classification of lupus nephritis. International Society of Nephrology/Renal Pathology Society (ISN/RPS) 2003 (17;21) Numbers; median values or patients
Table 1: Descriptors of study cohort of SLE patients with (+LN) or without lupus nephritis.