What Do Abnormal Liver Tests Mean?

Abstract

Acquisition of a liver panel is generally performed during routine laboratory testing in asymptomatic patients and for the evaluation of those with suspected acute and/or chronic liver disease. While commonly referenced as liver function tests, the typical liver panel consists of elements that reflect hepatocellular injury, biliary tract disease, bilirubin metabolism, and protein synthesis. Despite its exclusion in the basic liver panel, an elevation in prothrombin time (PT), which is standardized through the international normalized ratio (INR), reflects a deficit in the hepatic synthesis of coagulation. Measures of hepatic function allow for prognostication of liver disease severity. One example is The Model for End-Stage Liver Disease (MELD), which incorporates measures of hepatic function (serum INR, total bilirubin, and creatinine) to formulate a score that predicts the 30-day mortality in patients with liver disease [1].

Establishment of disease chronicity is often the first step when evaluating patients with abnormalities in liver panel testing and classically relies on a combination of clinical history, physical exam findings, laboratory data, radiographic imaging, and histology. Unfortunately, the initial evaluation of these patients is often devoid of a majority of this data. This chapter will focus on the clinical utility of abnormal liver panel tests to aid the practitioner in developing a differential diagnosis of the possible etiologies of liver disease in hopes of better stratifying patients for further testing and management.