[Systemic lupus erythematosus in children with renal and hematologic manifestations. Relation to anti-nDNA antibodies]

Abstract

We studied prospectively 22 children with systemic lupus erythematosus. Serologic tests included: immunoglobulins, C3 and C4 determinations. Antinuclear antibodies, by the indirect immunofluorescence test, anti-nDNA, anti-nRNP, anti-Sm and anti-SSB (La) studies were also obtained. From the 22 patients there were 16 girls and 6 boys. The mean age at the onset of the disease was 12.4 years (range 8-15 years). Four patients had the disease before being 10 years old. We mainly observed two clinical subgroups, those with kidney injury, which included 11 patients (50%), and a second group of 8 patients (36%) with prominent hematologic manifestations, 4 with hemolytic anemia and 4 with thrombocytopenic purpura. The patients with kidney disease included 7 with diffuse proliferative glomerulonephritis, one with focal and one with mesangial glomerulonephritis. No biopsies were obtained in two patients. From the group with hematological disturbances, only one patient with hemolytic anemia developed renal involvement during her evolution. Three of the 22 patients presented lymphoproliferative disorders in coexistence with systemic lupus erythematosus. The presence of anti-nDNA antibodies and the decrease of C3, were statistically associated with kidney disease, but not with the hematologic manifestations. Nevertheless 50% of patients with hemolytic anemia and thrombocytopenic purpura have positive anti-nDNA and low C3 determinations. If immunochemical differences between the anti-nDNA antibodies in these groups of patients with systemic lupus erythematosus can establish a distinction in their clinical evolution with or without nephropathy is an interesting question that remains to be determined.