Renal tubular dysfunction in children with systemic lupus erythematosus.
Renal tubular and glomerular function was studied in patients under 18 years of age with childhood-onset systemic lupus erythematosus (SLE) in relation to disease activity in two groups: patients with clinical or laboratory evidence of lupus nephritis and those without (lupus non-nephritis). We reviewed 11 patients with lupus non-nephritis and 10 patients with lupus nephritis over a 12-month period. The measured glomerular filtration rates had a tendency to be lower in the lupus nephritis group. Glomerular dysfunction was manifest in the lupus nephritis group with elevated urinary albumin/creatinine ratios (P <0.001). Markers of tubular function were measured and compared with data from 94 controls. The lupus nephritis group had elevated urinary NAG [N-acetyl-beta-D-glucosaminidase (P =0.001)] and RBP [retinol-binding protein (P =0.03)] levels. Tubular dysfunction with elevated urinary NAG levels was present in 2 lupus non-nephritis patients with no evidence of glomerular disease. The cohort of patients in this study was followed and 2 lupus non-nephritis patients with the highest urinary RBP levels developed evidence of glomerular dysfunction and biopsy-proven lupus nephritis. Evidence of tubular dysfunction in lupus non-nephritis patients may help to identify lupus nephritis prior to the onset of albuminuria.
Marks
Stephen D
SD
Nephro-Urology Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK. S.Marks@ich.ucl.ac.uk
Shah
Vanita
V
Pilkington
Clarissa
C
Woo
Patricia
P
Dillon
Michael J
MJ
D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D005919:Glomerular Filtration Rate / Q000502:physiology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000150:complications*; D008181:Lupus Nephritis / Q000209:etiology / Q000503:physiopathology*; D015995:Prevalence; D015499:Renal Tubular Transport, Inborn Errors / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology