Related Experiment Videos
The use of hepatocyte extraction fraction to evaluate neonatal cholestasis
V Tolia1, S R Kottamasu, D Tabassum
1Department of Pediatrics, Children's Hospital of Michigan, Detroit, USA. vtolia@med.wayne.edu
Insights
Hepatobiliary scintigraphy's hepatocyte extraction fraction (HEF) does not predict liver function, diagnosis, or outcome in infants with neonatal cholestasis. A low HEF value alone does not indicate a poor prognosis.
Area of Science:
- Hepatology
- Pediatric Gastroenterology
- Nuclear Medicine
Background:
- Hepatobiliary scintigraphy is a standard diagnostic tool for neonatal cholestasis.
- Hepatocyte extraction fraction (HEF) is calculated during this test and is believed to reflect liver function.
- A low HEF may indicate severe hepatocellular disease.
Purpose of the Study:
- To determine if HEF correlates with synthetic liver function in neonatal cholestasis.
- To assess if HEF can differentiate obstructive from nonobstructive causes of neonatal cholestasis.
- To evaluate HEF's ability to predict outcomes in neonatal cholestasis.
Main Methods:
- Retrospective analysis of 68 hepatobiliary scintigraphy studies in infants with neonatal cholestasis over 6 years.
- HEF values were analyzed in relation to liver function tests (albumin, prothrombin time) and bilirubin levels.
- HEF was compared across different etiologies of cholestasis and patient outcomes.
Main Results:
- Median HEF was 25% (range, 3.3%–100%); 67 of 68 patients had available HEF values.
- No significant correlation was found between HEF and synthetic liver function tests or bilirubin levels.
- HEF did not correlate with specific diagnoses (e.g., biliary atresia, neonatal hepatitis) or outcomes (resolution, transplantation, death).
Conclusions:
- A single HEF measurement is not valuable for assessing synthetic liver function, diagnosis, or prognosis in neonatal cholestasis.
- Isolated low HEF values should not be interpreted as indicative of a poor outcome in these patients.
Purpose:
Hepatobiliary scintigraphy is used routinely to evaluate infants with neonatal cholestasis. Hepatobiliary scintigraphy determines biliary patency by detecting radioactivity in the bowel on imaging, in duodenal and gastric aspirates, or all of these. During hepatobiliary scintigraphy, the hepatocyte extraction fraction (HEF) is calculated by deconvolution analysis. Normal values of HEF are more than 90%. It is believed that HEF may predict hepatic dysfunction, because, during hepatobiliary scintigraphy, the radiopharmaceutical used in this test is extracted by the hepatocytes from the blood stream. Therefore, a low value of HEF is seen with more severe hepatocellular disease. The goal of this study was to determine whether HEF has any correlation with synthetic liver function, whether HEF can differentiate obstructive from nonobstructive lesions that cause neonatal cholestasis, and whether HEF can predict the outcome of the different causes of neonatal cholestasis.
Methods:
A retrospective analysis of 68 hepatobiliary scintigraphy results was done in patients with neonatal cholestasis for a period covering 6 years.
Results:
The HEF was available in 67 of these 68 patients, with a median value of 25% (range, 3.3% to 100%). The results of synthetic liver function tests (i.e., albumin and prothrombin time) were normal in all infants with neonatal cholestasis. No significant correlation was detected between HEF and the serum levels of total and direct bilirubin, albumin, alkaline phosphatase, and prothrombin time by exploratory data analysis (R = 0.08; small, P > 0.2). The HEF values in different causes of neonatal cholestasis were compared: extrahepatic biliary atresia, neonatal hepatitis, and a miscellaneous category consisting of alpha1-antitrypsin deficiency, ischemic hepatitis, paucity of bile ducts, and others. The outcomes of these diseases were assessed as resolution, continuing disease, transplantation, or death, but no predictive correlation was found with HEF.
Conclusions:
A single determination of HEF is of no value in assessing synthetic liver function (as assessed by albumin and prothrombin time), specific diagnoses, and outcomes in patients with neonatal cholestasis. Therefore, a low isolated value of HEF should not be considered suggestive of poor prognosis and outcome in these patients.