Determination of circulating immune complexes, C3 and C4 complement components and anti-DNA antibody in different classes of lupus nephritis.
Circulating immune complexes (CIC) were measured in 237 sera from children who underwent a renal biopsy during the course of systemic lupus erythematosus. CIC-positive sera contained a lower mean level of C3 but not C4. Anti-DNA antibody was similar in CIC-positive and negative sera. The World Health Organization classification of lupus nephritis was used to categorize the biopsies. CIC, C3, C4 and anti-DNA antibody were determined to assess whether they correlated with the severity of renal lesions. Of 25 sera obtained at renal biopsy from patients with classes 2, 3 and 4, 16 were positive for CIC. C3 was significantly lower in classes 3 and 4 than in class 2. C4 was reduced and anti-DNA antibody was present in classes 2, 3 and 4. Determination of the level of C3 but not C4, CIC or anti-DNA antibody correlates with the severity of lupus nephritis seen on renal biopsies. Nevertheless, performance of a renal biopsy is preferred.
D000888:Antibodies, Anti-Idiotypic / Q000032:analysis*; D000936:Antigen-Antibody Complex / Q000032:analysis* / Q000502:physiology; D003176:Complement C3 / Q000032:analysis*; D003181:Complement C4 / Q000032:analysis*; D004247:DNA / Q000032:analysis*; D005921:Glomerulonephritis / Q000276:immunology* / Q000473:pathology; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology* / Q000473:pathology
D000888:Antibodies, Anti-Idiotypic; D000936:Antigen-Antibody Complex; D003176:Complement C3; D003181:Complement C4; D004247:DNA