Clinicopathology of childhood-onset renal systemic lupus erythematosus

To determine the clinicolaboratory renal manifestations; glomerular, extra-glomerular histopathologic lesions; renal tubular dysfunction (RTD) frequency and outcome of a short-term renal follow up in Nigerian children with systemic lupus erythematosus (SLE).

A non-randomized prospective study of consecutive cases of childhood-onset SLE with nephropathy was conducted. Baseline/follow-up clinicolaboratory data were collected. Each patient was followed up for 12 months.

Seven of the 11 children studied were girls. The median age at diagnosis was 11.0 years. Median diagnosis time interval (1.9 years) and median time of renal disease onset (1.0 year) were similar. Hypertension, nephrotic syndrome and acute renal failure (ARF) occurred in 45.5%, 54.5% and 63.7% of the patients, respectively. The glomerular lesions were non-proliferative lupus nephritis (LN) in 9.0% (class II LN); focal (class III LN) and diffuse (class IV LN) proliferative LN (PLN) in 27.0% and 64.0%, respectively. Tubulointerstitial nephritis (TIN, 91.0%) and RTD (64.0%) were common. ARF (P = 0.033) and RTD (P = 0.015) were significantly associated with severe TIN. Complete renal remission rate at end-point was 71.4%. Relapse and renal survival rates were 14.3% and 86.0%, respectively. RTD was persistent in 43.0%.

Renal function disorders, diffuse PLN and extra-glomerular lesions were frequent. Significant association of ARF and RTD with severe TIN in this series suggests the need for early renal tubular function (RTF) assessment in our SLE patients. Deranged RTF may be marker of severe TIN in SLE warranting early confirmatory renal biopsy and aggressive interventional treatment.