Bilirubin, Indirect

Laboratory assay overview

Evaluation for liver and biliary disease

Laboratory assay overview

Liver and biliary tests are useful in the differential diagnosis of jaundice from bilirubin overproduction (hemolysis), decreased uptake (Gilbert disease), decreased conjugation (hepatocellular disease, familial, drug-induced, pregnancy; obstructive bile duct disease).

Laboratory assay overview

To assist with control of blood glucose levels, the American Diabetes Association (ADA) has recommended glycated hemoglobin testing (HbA1c) twice a year for patients with stable glycemia, and quarterly for patients with poor glucose control. Interpretative ranges are based on ADA guidelines.

Laboratory assay overview

This panel may be helpful in assessing liver injury, diagnosing liver diseases, and monitoring treatment of liver diseases and adverse effects of hepatotoxic drugs [1]. This panel includes total protein, albumin, globulin (calculated), albumin/globulin ratio, total bilirubin, direct bilirubin, indirect bilirubin (calculated), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). ⁠⁠⁠⁠⁠⁠⁠ ALT, AST, ALP, and bilirubin are common liver chemistry analytes that can be used to evaluate liver injury. ALT is a more liver-specific marker than AST. The latter also is present in the peripheral circulation during episodes of skeletal, cardiac, and smooth muscle injury. Elevated ALT and AST levels disproportionate to ALP levels indicate hepatocellular injury; elevated ALP and bilirubin levels disproportionate to ALT and AST levels indicate cholestatic injury. In the absence of identifiable risk factors, ALT or AST levels above the upper limit of the normal range are associated with increased liver-related mortality [1]. Evaluation of direct and indirect bilirubin levels is helpful for assessing the possibility of hepatocellular disease [1]. Elevated direct bilirubin levels imply hepatocellular dysfunction or cholestasis. Albumin is a marker of liver synthetic function; low levels may indicate liver disease of more than 3 weeks' duration [1]. Total protein levels reflect the sum of albumin and globulins and may aid in the diagnosis of disorders involving the liver, kidney, or bone marrow. This panel may be useful in evaluating individuals who are taking hepatotoxic drugs as well as those with viral hepatitis, symptoms or signs of chronic liver disease, conditions associated with a high risk of developing liver disease, lifestyle risk factors for nonalcoholic fatty liver disease, or a family history of liver disease [2]. Because many liver diseases cause characteristic abnormalities in selected liver chemistry analytes, results of individual analytes in this panel may aid in differential diagnosis. An abnormal test result may need to be confirmed by repeat testing and/or performing a clarifying test. For example, measurement of gamma-glutamyl transferase activity (not included in this panel) can help determine whether an elevated ALP result reflects hepatic disease [1]. Note that liver enzymes are markers of liver injury, not direct measurements of hepatic function. Bilirubin, albumin, and prothrombin time are markers of liver synthetic function [1,2]. The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings. References 1. Kwo PY, et al. Am J Gastroenterol. 2017;112(1):18-35. 2. Newsome PN, et al. Gut. 2018;67(1):6-19.

Laboratory assay overview

This reflex provides a cost-effective, medically justified, and guideline supported approach to evaluating a patient at risk of NAFLD with liver fibrosis. If the FIB-4 index is ≥1.30, the ELF score is performed.

Laboratory assay overview

This panel may be helpful in assessing liver injury, diagnosing liver diseases, and monitoring treatment of liver diseases and adverse effects of hepatotoxic drugs [1]. This panel includes albumin, total bilirubin, direct bilirubin, indirect bilirubin (calculated), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). ALT, AST, ALP, and bilirubin are common liver chemistry analytes that can be used to evaluate liver injury. ALT is a more liver-specific marker than AST. The latter also is present in the peripheral circulation during episodes of skeletal, cardiac, and smooth muscle injury. Elevated ALT and AST levels disproportionate to ALP levels indicate hepatocellular injury; elevated ALP and bilirubin levels disproportionate to ALT and AST levels indicate cholestatic injury. In the absence of identifiable risk factors, ALT or AST levels above the upper limit of the normal range are associated with increased liver-related mortality [1]. Evaluation of direct and indirect bilirubin levels is helpful for assessing the possibility of hepatocellular disease [1]. Elevated direct bilirubin levels imply hepatocellular dysfunction or cholestasis. Albumin is a marker of liver synthetic function; low levels may indicate liver disease of more than 3 weeks' duration [1]. This panel may be useful in evaluating individuals who are taking hepatotoxic drugs as well as those with viral hepatitis, symptoms or signs of chronic liver disease, conditions associated with a high risk of developing liver disease, lifestyle risk factors for nonalcoholic fatty liver disease, or a family history of liver disease [2]. Because many liver diseases cause characteristic abnormalities in selected liver chemistry analytes, results of individual analytes in this panel may aid in differential diagnosis. An abnormal test result may need to be confirmed by repeat testing and/or performing a clarifying test. For example, measurement of gamma-glutamyl transferase activity (not included in this panel) can help determine whether an elevated ALP result reflects hepatic disease [1]. Note that liver enzymes are markers of liver injury, not direct measurements of hepatic function. Bilirubin, albumin, and prothrombin time are markers of liver synthetic function [1,2]. The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings. References 1. Kwo PY, et al. Am J Gastroenterol. 2017;112(1):18-35. 2. Newsome PN, et al. Gut. 2018;67(1):6-19.

Laboratory assay overview

This panel may be helpful in assessing liver injury, diagnosing liver diseases, and monitoring treatment of liver diseases and adverse effects of hepatotoxic drugs [1]. This panel includes total protein, albumin, globulin (calculated), albumin/globulin ratio, total bilirubin, direct bilirubin, indirect bilirubin (calculated), alkaline phosphatase (ALP), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). ALT, AST, ALP, and bilirubin are common liver chemistry analytes that can be used to evaluate liver injury. ALT is a more liver-specific marker than AST. The latter also is present in the peripheral circulation during episodes of skeletal, cardiac, and smooth muscle injury. Elevated ALT and AST levels disproportionate to ALP levels indicate hepatocellular injury; elevated ALP and bilirubin levels disproportionate to ALT and AST levels indicate cholestatic injury. In the absence of identifiable risk factors, ALT or AST levels above the upper limit of the normal range are associated with increased liver-related mortality [1]. Evaluation of direct and indirect bilirubin levels is helpful for assessing the possibility of hepatocellular disease [1]. Elevated direct bilirubin levels imply hepatocellular dysfunction or cholestasis. Albumin is a marker of liver synthetic function; low levels may indicate liver disease of more than 3 weeks' duration [1]. Total protein levels reflect the sum of albumin and globulins and may aid in the diagnosis of disorders involving the liver, kidney, or bone marrow. This panel may be useful in evaluating individuals who are taking hepatotoxic drugs as well as those with viral hepatitis, symptoms or signs of chronic liver disease, conditions associated with a high risk of developing liver disease, lifestyle risk factors for nonalcoholic fatty liver disease, or a family history of liver disease [2]. Because many liver diseases cause characteristic abnormalities in selected liver chemistry analytes, results of individual analytes in this panel may aid in differential diagnosis. An abnormal test result may need to be confirmed by repeat testing and/or performing a clarifying test. For example, measurement of gamma-glutamyl transferase activity (not included in this panel) can help determine whether an elevated ALP result reflects hepatic disease [1]. Note that liver enzymes are markers of liver injury, not direct measurements of hepatic function. Bilirubin, albumin, and prothrombin time are markers of liver synthetic function [1,2]. The results of this test should be interpreted in the context of pertinent clinical and family history and physical examination findings. References 1. Kwo PY, et al. Am J Gastroenterol. 2017;112(1):18-35. 2. Newsome PN, et al. Gut. 2018;67(1):6-19.

Laboratory assay overview

The FIB-4 index is a simple non-invasive approach using selected laboratory measures (AST, ALT, platelet count) in combination with patient age to assess if an individual is at higher risk for advanced liver fibrosis (F3-F4).