C4A and Thrombocytopenia: The hematocrit was 30 (unchanged for 3 months prior and after visit), mean corpuscular volume 90, haptoglobin <6 mg/dL (normal 39-195 mg/dL), absolute reticulocyte count of 17 000/mm3 (normal 241 00-877 00), anti-dsDNA of 20, C3 of 49 mg/dL (normal 79-152), C4 of 10 mg/dL (normal 12-42), stable thrombocytopenia (109 00/mm3), normal urine protein creatinine ratio of 0.17 (normal 0.00-0.19 mg/g creatinine), normal liver function test (2 months prior and 3 months after the visit), and erythrocyte sedimentation rate was 13.