The clinical importance of conventional and quantitative liver function tests in liver transplantation

Abstract

The advantages and disadvantages of using monoethylglycinexylidide (MEGX), the major metabolite of lidocaine, as a probe of hepatic function in liver transplantation are reviewed. A 'real time' test of liver function should give a measure of current hepatocellular capacity rather than reflect past damage. The hepatic metabolism of lidocaine to MEGX is the basis of a flow-dependent dynamic test of liver function. In pre-transplantation patients, data from this MEGX test support its role in assessing the risk of morbidity and mortality. In assessing the liver transplant donor, there are differences concerning its apparent usefulness and these must be resolved. In the liver transplant recipient, this MEGX test is also useful for measuring real-time hepatic metabolizing activity, and low MEGX values reflect the clinical condition of the patient. At present, however, this test has several limitations. Therefore, a comprehensive evaluation, not only by the MEGX test but also by a combination of other conventional liver function tests (biochemical parameters, etc.), or with histological evaluation, is thought to be desirable for deciding whether a liver transplantation should be carried out or not.

Chlorzoxazone as a Cause of Acute Liver Failure Requiring Liver Transplantation

“…CZ is primarily metabolized by cytochrome P450 2E1 to 6-hydroxychlorzoxazone; approximately 74% is subsequently excreted as a glucuronide conjugate in the urine [2]. Given this high degree of selective metabolism by P450 2E1, CZ is frequently used as a pharmacologic probe of its activity and has been utilized as an indicator of liver function in selected candidates with liver disease and potential orthotopic liver transplantation recipients [3,4]. The activity of cytochrome P450 2E1 is modulated by medications and physiologic states, including fasting [5], obesity [7], alcoholism, and type 2 diabetes mellitus [6].…”

“…The activity of cytochrome P450 2E1 is modulated by medications and physiologic states, including fasting [5], obesity [7], alcoholism, and type 2 diabetes mellitus [6]. Specifically, chlorzoxazone 6-hydroxylation is enhanced by obesity and alcoholism [4,7], but neither condition has clearly been linked to toxicity of the drug. The patient presented here was not obese and had no significant history of alcohol use or type 2 diabetes mellitus.…”

Nicht-Isotopen Tyrosin-Kinetik mit dem Dipeptid Alanyl-Tyrosin zur Beurteilung der Organfunktion bei Lebertransplantation – eine Pilotstudie

“…prothrombin time, liver enzymes, bilirubin levels, hypoglycemia, acidosis) can be greatly misleading as they are influenced by numerous factors not dependent on hepatic function [14][15][16]. Furthermore, many of these standard indicators reflect the degree of cell damage caused by the procedure rather than the remaining metabolic capacity of the graft.…”

Lidocaïne test for easier and less time consuming assessment of liver function in several hepatic injury models

“…In humans, lidocaïne is mainly deethylated to its primary metabolite the monoethylglycinexylidide (MEGX) and is hydroxylated to hydroxy-lidocaïne (OH-lido) [13,14]. MEGX formation rate reflects quantitative hepatocyte metabolic activity, hepatocyte numbers, and hepatic blood flow [6,[15][16][17].…”