Which serologic tests are most useful when following a patient with lupus nephritis?
- • dsDNA, can elevate with disease flare
- • Complement component levels Decreased complement component levels (e.g., C3 and C4) as well as total hemolytic complement (CH50), which also correlate with the activity of renal disease
- • Remember that many SLE patients have partial C4 deficiency and, therefore, may always have a low C4 level. In those patients, only C3 levels can be followed.
- • SLE patients with crescents are more likely to be perinuclear anitneutrophil cytoplasmic antibody-positive (usually not against myeloperoxidase).
It should be emphasized that some patients with high levels of anti-dsDNA antibodies and low complement levels never develop nephritis. Alternatively, glomerulonephritis can occur in an SLE patient who has normal complement levels and no elevated levels of anti-dsDNA antibodies (especially membranous lupus nephritis).