Plasma endothelin-1 concentrations in children with cirrhosis and their relationship to renal function and the severity of portal hypertension.

BACKGROUND: Plasma endothelin-1 (ET-1) is a potent vasoconstrictor peptide involved in the pathogenesis of several disorders. Endothelin-1 concentrations are increased in adult patients with cirrhosis. However, little is known about ET-1 concentrations in children with cirrhosis. METHODS: Radioimmune assay was used to measure plasma ET-1 concentrations in 19 children with cirrhosis (8 patients with ascites, and 11 without ascites), and 11 age- and sex-matched healthy children. The plasma ET-1 concentrations were correlated with the mean blood pressure, creatinine clearance, and severity of portal hypertension, as measured by portal flow volume and portal flow velocity. RESULTS: Patients with cirrhosis and ascites had increased plasma ET-1 concentrations compared with patients who did not have ascites (6.8 pg/mL +/- 0.62 pg/mL vs. 4.6 pg/mL +/- 0.35 pg/mL; mean +/- SEM; < 0.01) and controls (3.6 pg/mL +/- 0.27 pg/mL; mean +/- SEM; < 0.0005). Plasma ET-1 concentrations were higher in patients with cirrhosis who did not have ascites compared with controls ( < 0.005). No significant differences were observed between concentrations of the patients with cholestasis and those without cholestasis (5.4 pg/mL +/- 0.52 pg/mL vs. 5.2 +/- 0.32 pg/mL; mean +/- SEM; = 0.1). Plasma ET-1 concentrations correlated positively with the mean blood pressure ( = 0.58; < 0.05) and negatively with renal function, as measured by creatinine clearance ( = -0.7; <0.005). However, no correlation was detected between ET-1 concentrations and portal flow volume ( = -0.02; = 0.4) or portal flow velocity ( = -0.16; = 0.4). CONCLUSIONS: Plasma ET-1 concentrations are increased in children with cirrhosis, with or without ascites, compared with controls. Patients with cirrhosis and ascites have increased ET-1 concentrations compared with those without ascites. The degree of increase does not relate to the severity of portal hypertension. This increase tends to maintain systemic blood pressure but is associated with a decrease in renal function.

Evaluation of the triangular cord sign in the diagnosis of biliary atresia.

BACKGROUND: Infantile cholestasis continues to represent a diagnostic challenge. It is very important to diagnose surgically correctable disorders, such as biliary atresia, in a timely manner to prevent progressive damage to the liver. It has been recently suggested that the triangular cord (TC) sign is a simple and useful tool in the diagnosis of biliary atresia. METHODS: We prospectively studied 65 infants presenting with conjugated hyperbilirubinemia (age range: 32-161 days). All patients underwent ultrasonographic examination with a 7.0-MHz transducer (Acuson, Mountain View, CA). The TC was defined as a triangular, or tubular, echogenic density seen immediately cranial to the portal vein bifurcation. RESULTS: The TC sign was identified in 25 infants, and all of them had histologic features suggestive of biliary atresia; the diagnosis was confirmed at surgery by gross morphology of hepatobiliary system, and liver biopsy, with or without intraoperative cholangiogram. Among the 40 patients who did not have the TC sign, 6 had paucity of the intrahepatic bile ducts. Three had alph-1-antitrypsin deficiency, and 31 had neonatal hepatitis. None of the 40 patients who did not have the TC sign developed acholic stools. Seven patients with biliary atresia were followed by ultrasonographic examination for 6 months after the Kasai procedure. The TC sign disappeared in all patients after the surgery; however, the TC sign reappeared in 3 patients who developed progressive cholestasis after the procedure. CONCLUSION: The TC sign is a simple, timesaving, and reliable diagnostic tool in the evaluation of infants with infantile cholestasis. The TC sign may also prove to be helpful in following patients after hepatoportoenterostomy. We suggest a new diagnostic strategy for patients suspected to have biliary atresia. When the TC sign is visualized, the patient should undergo intraoperative cholangiogram to confirm the diagnosis of biliary atresia, reserving percutaneous liver biopsy for those patients in whom the TC sign could not be detected.

Monoethylglycinexylide formation in assessing pediatric donor liver function.

Lidocaine metabolism to monoethylglycinexylide (MEGX) has been described as a novel method to assess liver function in adult transplant donors and recipients. While this assay appears to offer a number of advantages over existing liver function tests, limited work has been done to evaluate its potential in the pediatric population. This study evaluated MEGX formation in potential pediatric liver donors (n = 35) and a control group of children (n = 16). The mean MEGX formation was significantly higher in pediatric donors than in the control group (156 +/- 62 vs 106 +/- 33 ng/ml, p < 0.05). No correlation with age, total bilirubin, liver transaminases, or alkaline phosphatase could be made within each group. Significant differences in MEGX levels were noted when each group was compared to its adult counterpart. Both pediatric donors and controls had greater mean MEGX formation than has been reported for adult donors and controls (156 +/- 62 vs 127 +/- 61 ng/ml, p < 0.05 and 106 +/- 33 vs 72 +/- 36 ng/ml, p < 0.05, respectively). Drugs that alter lidocaine pharmacokinetics and their potential influence on MEGX formation were evaluated in the pediatric donor group. Donors exposed to hepatic enzyme-inducing drugs had a higher mean MEGX formation (187 +/- 60 vs 146 +/- 63 ng/ml). No significant differences were noted between donors receiving and not receiving vasopressors. In conclusion, the significant differences between pediatric and adult MEGX formation should be noted when establishing reference or normal ranges for this diagnostic test. Furthermore, concomitant drug therapy may significantly alter MEGX formation.

New methods for assessing liver function in infants and children.

Assessment of liver function in infants and children has traditionally relied on static indices of hepatic structure, cellular integrity, or function and are often based on the release of substances from damaged tissues. There has been a rapid development of dynamic tests based on the measurement of substances metabolized or cleared from blood by the liver. These tests, which have been touted to offer a more precise quantitative estimation of hepatic functional capacity, include the measurement of serum bile acids and the hepatic metabolism of xenobiotic compounds such as caffeine and lidocaine. Serum bile acid measurements appear to be reliable indicators of enterohepatic circulation and may be useful in screening for liver disease. It has been observed that caffeine metabolism is decreased in patients with various forms of liver disease in correlating with disease status. Caffeine has the advantage of being well tolerated when administered orally; the saliva level parallels the serum concentration, making a non-invasive test feasible. Lidocaine is metabolized by oxidative de-ethylation to monoethylglycinexylide (MEGX); analysis of MEGX by common laboratory instrumentation makes rapid evaluation of liver function possible. The MEGX values correlated were with pretransplant liver disease assessment. These tests are currently being evaluated at other centers and, if the initial studies are repeated, they offer the hope for reliable dynamic tests of hepatic function.

Complications of percutaneous liver biopsy in children.

To determine the frequency and nature of complications after liver biopsy and whether risk factors could be identified to predict these complications, the medical records of all patients (age, 1 week to 28 years) who underwent a percutaneous liver biopsy at Children's Hospital over a 6-year period (1981-1986) were reviewed. Data were collected from 469 (97%) of 483 eligible charts. Twenty-one patients (4.5%) experienced major complications including bile leak (n = 3, 0.6%), prolonged drainage of ascitic fluid (n = 1, 0.2%), pneumothorax (n = 1, 0.2%), bleeding requiring transfusion (n = 13, 2.8%), and death (n = 3, 0.6%). A subgroup of patients (n = 37) with cancer or bone marrow transplantation was found to be at a nearly fivefold greater risk for transfusion than patients with other diagnoses (P = 0.02). All three deaths in previously stable patients occurred in this same high-risk group of patients with cancer or bone marrow transplantation (P less than 0.001). Two deaths resulted from disseminated intravascular coagulation and one from bleeding. Diagnosis, age, number of percutaneous passes, and prebiopsy coagulation studies were not predictive of subsequent complications. It is concluded that bleeding that requires transfusion is the most common liver biopsy complication and that it occurs more frequently in children than previously reported. Children with cancer or those who have undergone bone marrow transplantation are at a greater risk for bleeding and death following percutaneous liver biopsy.

Liver transplantation in the pediatric population: indications and monitoring.

Advances in immunosuppressive therapy and surgical technique have brought liver transplantation to an effective therapeutic option for children with end-stage liver disease. The indications and contraindications for transplantation, recipient selection, ethical and financial considerations, and quality of life after transplantation are outlined in this review.

Assessment of lidocaine metabolite formation as a quantitative liver function test in children.

Lidocaine, an aminoethylamide, undergoes deethylation in the liver after intravenous injection, resulting in the formation of monoethylglycinexylidide. Serum monoethylglycinexylidide concentration can be measured by a simple, rapid fluorescent polarization immunoassay. We sought to determine whether lidocaine metabolism, as indicated by monoethylglycinexylidide formation, could be used as a quantitative index of hepatic function. Therefore we measured monoethylglycinexylidide formation in 10 healthy children and in 28 children with chronic liver disease. Patients with chronic liver disease were divided by disease severity as being at low, moderate or high risk for deterioration based on a clinical scoring system for liver transplant candidates. In healthy controls, the peak monoethylglycinexylidide concentration 15 min after injection of lidocaine (1 mg/kg) was 97 +/- 12 micrograms/L (mean +/- S.E.). However, monoethylglycinexylidide concentration was decreased in 28 children with chronic liver disease (32 +/- 5 micrograms/L, p less than 0.001). Furthermore, this value was inversely proportional to the severity of liver disease. The mean difference in monoethylglycinexylidide concentration between the low-risk and high-risk groups was statistically significant (42 +/- 6 vs. 11 +/- 4 micrograms/L, respectively, p less than 0.01). We conclude that the rate of formation of the lidocaine metabolite monoethylglycinexylidide is decreased in patients with chronic liver disease and is inversely related to disease severity. Therefore measurement of monoethylglycinexylidide concentration after lidocaine injection may be used as a quantitative assessment of liver function in children. We speculate that monoethylglycinexylidide formation may be a useful prognostic index in children with liver disease.