Renal pathology and long-term outcome in childhood SLE

Renal histology is increasingly used as a guide for therapy and prognosis in SLE but data in children are few and/or short-term. We assessed renal histological features in 19 children with SLE to determine whether these features are useful in predicting long-term outcome. Mean age at biopsy was 10 +/- 1.7 years old, male to female ratio was 1:2.8. Fourteen patients (73%) had diffuse proliferative lupus nephritis. Renal histology was evaluated using an activity index (AI) and chronicity index (CI). Clinical assessment of renal function at biopsy and outcome were graded according to urinalysis and serum creatinine. Renal function at biopsy correlated well with AI (p < 0.001) but not CI. At short-term follow-up (30 months), 3 patients had died from sepsis and another 2 reached end-stage renal disease. CI predicted poor clinical outcome, i.e. death or renal failure (p < 0.005) but AI did not. At long-term follow-up (mean 92.1 +/- 26.8 months) only one more patient reached end-stage renal disease. In others renal function assessment showed improvement or were stable. Neither CI nor AI correlated with clinical outcome. We conclude that although AI correlates well with renal function at biopsy and CI with short-term prognosis, neither can predict long-term outcome. Treatment may have altered the natural course of disease in these patients.