Over a 49-month treatment period (34 doses), the patient achieved sustained remission, with complete resolution of abdominal symptoms, normalization of computed tomography findings, stable Systemic Lupus Erythematosus Disease Activity Index scores (0-4), decreasing anti-double-stranded DNA titers (<20 IU/mL), and rising serum complement C3 levels (>0.6 g/L). Here, C3 is linked to systemic lupus erythematosus.