Sensitivity and specificity of plasma and urine complement split products as indicators of lupus disease activity

✍ Scribed by Susan Manzi; Joan E. Rairie; A. Betts Carpenter; Robert H. Kelly; Santhi P. Jagarlapudi; Susan M. Sereika; Thomas A. Medsger Jr.; Rosalind Ramsey-Goldman

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 976 KB
• Volume: 39
• Category: Article
• ISSN: 0004-3591
• DOI: 10.1002/art.1780390716

✦ Synopsis

Objective. To determine if measurement of serum complement split products (C4d, Bb, C5b-9) is better than conventional C3 and C4 measurements in distinguishing patients with varying degrees of lupus disease activity, and to determine if the presence of C3d in urine is helpful in distinguishing lupus patients with from those without early lupus nephritis.

Methods. Lupus disease activity was prospectively determined at 3 consecutive visits an average of 4 months apart, using the Systemic Lupus Activity Measure (SLAM), the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), and physician global assessment (PGA). Blood samples were evaluated for the presence of C4d, Bb, and C5b-9 by quantitative microsassay plate enzyme immunoassay at each patient visit. We characterized urinary excretion of C3 fragments (with attention to C3d) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with Western blotting.

Results. Thirty-one SLE patients were enrolled in the study. The mean SLAM score and the mean SLEDAI score each correlated well with the PGA at all 3 visits. A Supported by grants from the Lupus Foundation of America