Uncertainty in liver function assessment on the basis of single-point galactose concentration

Assessment of liver function in chickens using galactose and indocyanine green clearances

Values for galactose and indocyanine green (ICG) clearances, and plasma and serum biochemical markers of liver dysfunction were determined in normal chickens and following coeliotomy, and compared with birds after partial hepatectomy. Clearance tests, and serum and plasma biochemistry were performed 4h, and 4 and 7 days after surgery. Coeliotomy and manipulation of the liver did not delay clearance of either compound. Partial hepatectomy resulted in elevation of galactose single point concentrations but did not significantly alter galactose clearance (GEC) values. Clearance values of ICG were not significantly altered. Biochemical values were not significantly elevated in birds after a partial hepatectomy in comparison with birds after coeliotomy. Galactose single point concentrations have the potential to become a simple, relatively non-invasive method of screening for liver disease, with GEC tests having the potential to quantify the degree of loss of functional hepatic mass.

Predicting liver failure following major hepatectomy

Pre-operative determination of the risk of liver dysfunction has come under criticism with regards to its usefulness in clinical practice. Opinion is split between centres which use such tests uniformly on all patients and those where clinical judgment alone is used. Published data would not suggest any difference in mortality, morbidity or liver failure rates between these groups. This review outlines and presents the evidence for pre-operative quantification of functional liver remnant volume.

The utility of the 13C-galactose breath test as a measure of liver function

BACKGROUND

The 13C-galactose breath test has been reported to be an accurate, non-invasive method for the assessment of liver function.

AIMS

To determine the optimal doses of labelled and unlabelled carrier galactose necessary to perform the 13C-galactose breath test, to assess the utility of the 13C-galactose breath test in distinguishing between normal subjects and those with liver cirrhosis and to determine whether the 13C-galactose breath test can stratify patients with cirrhosis based on their Child-Pugh score.

METHODS

Twenty-three control subjects and 30 patients with liver cirrhosis received fixed doses of unlabelled carrier galactose and labelled 13C-galactose. Breath samples were collected just before and at 30-min intervals up to 4 h after the ingestion of unlabelled carrier galactose and labelled 13C-galactose. Each sample was analysed for its 13CO2 content.

RESULTS

Doses of 25 g/m2 of unlabelled carrier galactose and 100 mg of 13C-galactose had the greatest sensitivity (93%; 95% confidence interval, 76-99%) and specificity (87%; 95% confidence interval, 65-97%) for distinguishing between normal subjects and cirrhotics when the test was performed 2 h after ingestion. The 13C-galactose breath test was also able to distinguish between class A and class B or C cirrhotics.

CONCLUSION

The 13C-galactose breath test is a useful non-invasive tool for distinguishing between healthy subjects and patients with liver cirrhosis and between cirrhotics with well-compensated liver disease and those with decompensated liver disease.

Inducibility of microsomal liver function may differentiate cirrhotic patients with maintained compared with severely compromised liver reserve

BACKGROUND AND AIM

Quantitative tests of liver function (QTLF) can be modulated by enzyme-inducing agents. The objective of the study was to examine changes in QTLF after treatment with Phenobarbital, a potent cytochrome P450-inducing agent.

METHODS

Forty-six consecutive patients with liver cirrhosis Child-Pugh score B and C (34 alcoholic, 12 hepatitis C) and a compromised aminopyrine breath test (ABT) were included. Thirty-six patients (group I) received phenobarbitone (150 mg) for 7 days. Ten patients (group II) received a placebo. The QTLF, which included ABT (microsomal liver function), galactose elimination capacity (GEC, cytosolic liver function), sorbitol clearance (SCl, liver plasma flow) and indocyanine green clearance (ICG, liver perfusion) was carried out before and after pharmacological induction.

RESULTS

Group I showed a basal ABT of 0.18 +/- 0.11% dose.kg/mmol CO2 (normal >0.6%), which increased significantly after induction (172%, P < 0.05), whereas in group II the ABT values did not change. In group IB, a subgroup of group I which exceeded the basal threshold value of 0.30% after stimulation (n = 22), the ABT values increased significantly to 0.44 +/- 0.17% (244%, P < 0.01). The GEC, SCl and ICG remained unchanged before and after induction.

CONCLUSIONS

After pharmacological induction, microsomal liver function increased significantly in a subgroup of patients with liver cirrhosis, whereas the GEC, SCl and ICG remained unchanged. Inducibility of the microsomal liver function could be used as a novel parameter of functional hepatic reserve and prognosis in cirrhosis.

Potential use of pharmacological markers to quantitatively assess liver function during liver transplantation surgery

Early functioning of the transplanted liver is of crucial importance to the recipient. This function may be assessed by measuring the disposition of substances that are mainly eliminated via the liver. None of the agents currently used is ideal for this purpose. Measurement of mono-ethyleneglycinexylidide (MEGX) formation from lignocaine is useful and has been widely used in liver transplantation to assess liver graft function. MEGX formation can be affected by the use of drugs that influence liver perfusion or interfere with the CYP450 enzyme system. Indocyanine green clearance is a convenient method but both blood flow and hepatocellular function affect the test results. Tests of caffeine clearance, galactose elimination capacity and antipyrine clearance all require time-consuming, technically cumbersome and expensive serial blood sampling. The aminopyrine breath test is non-invasive, but gastric emptying and the patient's physical state affect results. The potential hazard of exposure to radioactive compounds limits the wide clinical use of both aminopyrine and erythromycin breath tests. Monitoring the rate of recovery from neuromuscular blockade induced by vecuronium and rocuronium can provide valuable information on liver function.

[13C]-Galactose breath test: correlation with liver fibrosis in chronic hepatitis C

BACKGROUND

The galactose elimination capacity test is a quantitative liver function test that has been shown to be a potential surrogate marker for death in advanced chronic liver diseases. However, this test lacks sensitivity in early liver disease. The goal of this study was to evaluate a [13C]-galactose breath test (GBT) in a population of patients with chronic hepatitis C.

DESIGN

The GBT was performed in 10 control subjects and 50 patients with chronic hepatitis C; the results were compared with the METAVIR pathological scoring of liver biopsy specimens and with standard biochemical liver function tests.

RESULTS

In 10 patients, oral vs. intravenous administration of galactose yielded similar results for the GBT (3.01% +/- 0.12% dose h-1 for oral galactose vs. 2.98 +/- 0.21 for intravenous). The GBT was then performed orally in the remaining 40 patients and 10 control subjects. A significant difference was observed between control subjects and patients (4.51% +/- 0.18% vs. 2.97% +/- 0.14% dose h-1, P < 0.0001). A significant difference for GBT results was observed between each fibrosis stage, but not with regard to the activity score.

CONCLUSIONS

The GBT results are dependent on the severity of liver fibrosis in chronic hepatitis C. Further studies are needed to evaluate the usefulness of the GBT for the follow-up of chronic hepatitis C.