[Clinical and immunological features of lupus nephritis in children: retrospective analysis of 40 cases].

OBJECTIVE: To analyze the clinical and immunological features of children with lupus nephritis (LN). METHODS: Chart records of 40 (4 male and 36 female) LN children who were admitted consecutively between January, 2005 and December, 2010 were reviewed. The baseline demographic, pathological and immunological data were analyzed. RESULTS: In the 40 LN patients analyzed, the mean age of the disease onset was 10.6 ± 2.6 (range from 2.6 to 14.3) years, and 35 cases (88%) were school-age children. Proteinuria was detected in all 40 cases, including nephrotic-range proteinuria in 12 (30%) cases, and isolated proteinuria in 9 (22%) cases. Twenty-six (65%) patients had varying degrees of hematuria. Acute nephritis was the most common sub-type, accounting for 47% of the total cases. Among the 39 cases undergoing renal biopsy, 3 were unclassified and the remaining 36 were classified, respectively, as type IV LN (50%, 18 cases), type II LN (22%, 8 cases). In the histopathologcally classified case, 100% were antinuclear antibody-positive, 61% were anti-dsDNA-positive, and 89% showed varying degrees of decrease in serum C3 and C4 concentrations. Following treatment for 6 months, a high LN remission rate (95%) was achieved; the acute renal activity index remained higher in IV, V+III and V+IV subtypes than in other subtypes, while the chronic index and the degree of tubulointerstitial damage were not different between histopathological subtypes. CONCLUSIONS: The clinical manifestations of LN children are diverse. Clinically, acute nephritis is the most common form of LN in children. Histopathologically, type IV is the most frequent subtype of LN. Early treatment may result in significant disease remission.