C4A and systemic lupus erythematosus: She had a high erythrocyte sedimentation rate (ESR) of 92, positive anti nuclear antibodies (ANA) titer of 1:640 on Hep-2 cells, and a high anti-double-stranded deoxyribonucleic acid (dsDNA) antibody level of 15 IU/ml (positive if > 10 IU/ml), with low C3 and C4 complements of 0.5 g/l (low < 0.785 g/l) and 0.08 g/l (low < 0.145 g/l), respectively, compatible with findings of systemic lupus erythematosus (SLE).