complement C3, C4 testing
see also:
arthritis - clinical patterns
glomerulonephritis (GN)
introduction
complement testing is useless for screening for cause of arthritis but is often used to monitor disease activity in patients with SLE
decreased levels of complement arise from immune-complex disorders such as:
systemic lupus erythematosus (SLE)
selected forms of
vasculitis
(e.g., essential mixed cryoglobulinemia and rheumatoid vasculitis)
certain types of
glomerulonephritis (GN)
inherited complement deficiencies