Systemic lupus erythematosus (SLE) is an autoimmune disease with multiorgan involvement. Approximately 37-45% of patients with SLE will develop lupus nephritis, which negatively impacts patient survival. Testing for C1q antibodies assists in evaluating the risk of lupus nephritis development.
C1q antibodies are associated with active glomerulonephritis in patients with SLE. The presence of antibodies in patients with SLE indicates a higher risk for developing severe clinical manifestations of the disease. Specifically, the presence of C1q antibodies correlates with renal activity and flares, and the absence of antibodies indicates a low probability of lupus nephritis.
- Clinical sensitivity and specificity vary based on disease population and disease state
- Analytical sensitivity and specificity vary based on disease population and disease state as well as testing platform
- Negative: 0-19 units
- Equivocal: 20-39 units
- Positive: ≥40 units
- Not all patients with lupus nephritis will be positive for C1q antibodies
- The presence of C1q antibodies is not specific for SLE
Albuquerque BC, Salles VB, Tajra RDP, et al. Outcome and Prognosis of Patients With Lupus Nephritis Submitted to Renal Transplantation. Sci Rep. 2019;9(1):11611.