Transiently Elevated TC and sdLDL-C Levels and Falsely Low LDL-C Levels in Patients with Extrahepatic Cholangiocarcinoma

PURPOSE: Most patients diagnosed with extrahepatic cholangiocarcinoma (ECCA) exhibit cholestasis caused by obstruction of the bile duct. Cholestasis is associated with lipid disorders, but studies focused on the changing lipid parameters in patients with ECCA are lacking. Here, we observed lipid profiles in patients with ECCA and investigated whether the removal of biliary obstruction could correct dyslipidemia. PATIENTS AND METHODS: We consecutively included patients admitted to the hepatobiliary surgery department at the Affiliated Hospital of Xuzhou Medical University. The patients were divided into an ECCA group or a non-ECCA group based on the disease assessment. Patients with histological confirmation of ECCA were included in the ECCA group. Blood samples were collected on admission as well as five days after treatment. An automatic biochemistry analyzer was used to test liver function and serum lipid levels. Serum lipoprotein electrophoresis was performed using barbitone sodium buffer and Sudan black B. RESULTS: A total of 180 patients met inclusion criteria and were enrolled for this study. Of these, 76 patients were diagnosed with ECCA; all other patients were enrolled in the non-ECCA group. Total cholesterol (TC) and small and dense low-density lipoprotein cholesterol (sdLDL-C) levels were significantly elevated in the ECCA group. LDL-C levels were found to be slightly lower in the ECCA group. In the ECCA group, serum samples were detained in sample wells and lipoproteins failed to be separated. TC and sdLDL-C levels significantly decreased after cholestasis relief in the ECCA group. Lipoprotein electrophoresis revealed that patients with ECCA showed normal lipoprotein patterns after treatment. CONCLUSION: Patients with ECCA exhibited transiently elevated TC and sdLDL-C levels and falsely low LDL-C results. TC, sdLDL-C, and LDL-C levels could be restored to normal levels after biliary obstruction removal and cholestasis relief.