OBJECTIVES: Systemic lupus erythematosus (SLE) is a multisystem autoimmune inflammatory disease and one of the commonest and serious manifestations is lupus nephritis (LN). Studies say that 5 to 10% of patient with LN progress to end-stage renal disease. The objective of this study is to assess the renal severity in patients with LN at diagnosis for new-onset SLE.

METHODS: In Japan, SLE has been one of designated diseases for co-payment reduction or exemption. To be eligible for this, a doctor’s statement should be submitted. We extracted registration data of new-onset SLE patients with renal biopsy at diagnosis for application from fiscal years 2004 to 2008. Extracted data were analysed and compared in terms of patients’ age, gender, urinalysis result, serum creatinine, renal biopsy class, CKD stages and treatment history.

RESULTS: Of 9190 patients who were diagnosed with SLE and newly submitted application, 1353 patient record were extracted. 786 were with LN, of whom 49 were children and adolescents aged younger than 18 years and 737 were adults. The male/female ratio were 1:2.27 and 1:3.58 respectively. The commonest renal biopsy class was class IV, followed by classes V and III for both. Of 636 adults with LN (101 adults lacked either eGFR data or alubuminuria/proteinuria data), 158 cases fell in GFR category G1 (24.8%), 163 cases fell in G2 (25.6%), 107 cases are fell in G3a (16.8%), 106 cases fell in G3b (16.7%), 68 cases fell in G4 (10.7%) and 34 cases fell in G5 (5.3%). As to CKD risk, 9 (1.4%) were at moderately increased risk, 290 (45.6%) were at high risk and 307 (48.3%) were at very high risk.

CONCLUSIONS: Considering that 94% of adults with LN at diagnosis for new-onset SLE were at high risk of CKD, appropriate prevention of aggravation is important.