The results of laboratory tests to diagnosis systemic lupus erythematosus are as follows: total complement activity (CH50), 45 (50–150); complement C3 protein, 133 mg/dL (90–180 mg/dL); complement C4 protein, 14 mg/dL (10–40 mg/dL); anti-La/SSB antibodies, 160 U/ml (< 12 U/mL); anti-SSA/Ro, 200 U/mL (< 25 U/mL); anti-cyclic citrullinated peptides (anti-CCP) antibodies, 48 IU/mL (< 20 IU/mL) ; anti-double-stranded deoxyribonucleic acid antibody (anti-dsDNA), 70 IU/mL (< 35 IU/mL); fluorescence antinuclear antibody (FANA), 1/160. Here, SSB is linked to systemic lupus erythematosus.