Diffuse proliferative glomerulonephritis does not determine the worst outcome in childhood-onset lupus nephritis: a 23-year experience in a single centre

Abstract

INTRODUCTION: Lupus nephritis (LN) is the major indicator of morbidity and mortality in systemic lupus erythematosus (SLE). Many studies have found a significantly worse patient survival rate in patients with LN class IV than patients with other LN classes. OBJECTIVE: The aim was to describe the severity and outcomes of LN in a group of Thai children. METHODS: We retrospectively reviewed the patient files of children diagnosed with SLE aged < or =18 years in Songklanagarind Hospital, Southern Thailand, from 1985 to 2007. RESULTS: Of 216 SLE patients, 180 had renal biopsy results, and the others were excluded from analysis. There were 33 males and 147 females, average age 11.8 +/- 2.6 years (range 3.6-18.0), with a median follow-up period of 3.9 years (range 9 days to 19.4 years). Using the WHO LN classification, there were 9, 55, 5, 94 and 14 patients of classes I-V, respectively, as well as 2 with end-stage renal disease and 1 with IgM nephropathy. The mortality rate was 23% (42/180). Patients with LN class II had a similar renal and patient survival compared to patients with LN class IV (P = 0.3 and 0.2, respectively). Cox proportional hazard regression analysis in 177 patients (3 patients who had a renal biopsy result outside the WHO classification were omitted) showed that gender was an independent risk factor for survival. Males had 2.6 times the hazard rate compared to females (95% CI 1.2-5.7, P = 0.03), but LN classification, age and timing of the renal biopsy were not significant. CONCLUSION: Renal and patient survival in LN classes II and IV were similar. Gender was the only independent risk factor of mortality, with males at greater risk than females.