An observational study of outcome in SLE patients with biopsy-verified glomerulonephritis between 1986 and 2004 in a defined area of Southern Sweden: the clinical utility of the ACR renal response criteria and predictors for renal outcome

Abstract

Objectives: To test the utility of the World Health Organization (WHO) and International Society of Nephrology/Renal Pathology Society (ISN/RPS) criteria for lupus nephritis (LN) in systemic lupus erythematosus (SLE) and the American College of Rheumatology renal response criteria (ACR-RRC) for renal follow-up in an observational cohort.

Method: All 52 biopsy-verified cases of LN during 19 years were identified, and glomerular filtration rate (GFR), serum creatinine, proteinuria, haematuria, Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K), and complement were retrieved at diagnosis of nephritis, after 6 and 12 months, and at the latest visit. Forty-five renal biopsies were available for re-evaluation with the ISN/RPS criteria. Outcome was defined by the ACR-RRC and the final GFR.

Results: The mean follow-up time was 9 years; complete renal response (CRR) was achieved in 11 cases, end-stage renal disease (ESRD) in four, and nephrotic syndrome (NS) in one. The final GFR decreased with increasing age at biopsy (p < 0.01) and with interstitial manifestations added to the ISN/RPS classification (p < 0.05). The final GFR correlated with the decrease of proteinuria or casts and actual serum creatinine after 6 months of treatment (all p < 0.05). The outcome defined by ACR-RRC correlated with the nephrological components of SLEDAI-2K after 6 months of therapy (p < 0.01) and with the presence of antibodies to C1q at biopsy (p < 0.05).

Conclusions: Renal outcome is correlated with the response to treatment after 6 months and with the addition of interstitial changes to the ISN/RPS classification, which might add useful information for prediction. The ACR-RRC offers a defined alternative to categorize renal response.

Acknowledgements

This study was supported by grants from the Swedish Research Council (grants 2008-2201), the Swedish National Association Against Rheumatism, the Medical Faculty at Lund University, the Crafoord Foundation, Alfred Österlund’s Foundation, Greta and Johan Kock’s Foundation, King Gustav V’s 80th Birthday Fund, Lund University Hospital, the Swedish Society of Medicine, and the Foundation of the National Board of Health and Welfare. The expert secretarial help of Ingrid Mattsson-Geborek is greatly appreciated.