C4A and Hypertension: After adjusting for age, sex, hypertension, 24-h urinary protein, hemoglobin, serum albumin, the proportion of global glomerulosclerosis, eGFR, the proportion of crescents, serum uric acid, the proportion of fibrinoid necrosis, endocapillary hypercellularity, anti-double stranded DNA antibodies, and anti-SM antibodies, serum C4 was identified as an independent risk factor for tubular atrophy in patients with LN (Table 3).