This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
In a child, surgery was done for biliary stricture with hepatojejunal anastomosis. Postoperative bilirubin level after 2 weeks was 6 mg/dL from a preoperative level 12mg/dL. The reason for this could be: 
Select and explain. 
A. Normal lowering of bilirubin takes time, B. Anastomotic stricture, C. Delta bilirubin, D. Mistake in lab technique
C: Delta bilirubin
Answer: C: Delta bilirubin 
Explanation: Ans: C. Delta bilirubin(Ref Harrison 19/e p280, 18/e p325)Delta Bilirubin:Albumin-linked bilirubin fraction (delta fraction/biliprotein)Is pa of direct-reacting bilirubin fraction including conjugated bilirubin, covalently linked to albumin.Represents an impoant fraction of total serum bilirubin in patients with cholestasis & hepatobiliary disorders.Clearance rate of albumin-bound bilirubin from serum approximates half-life of albumin (12-14 days) rather than sho half-life of bilirubin (4 hours).Due to tight albumin bonding.