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What is Serum C3 is persistently low in the following except- and explain in detail?
Lupus nephritis: the significance of serological tests at the time of biopsy. ... As compared with a group of lupus patients without nephritis, patients with nephritis had lower serum complement C3 (p less than 0.05) and C4 (p less than 0.005) levels and higher serum DNA binding activity (p less than 0.001) Ref Harrison20th edition pg 277