2025 – PAGE 227 – GASTROENTEROLOGY

TRANSAMINITIS

Mild transaminitis is common with many viral infections. If transaminases are in the thousands, the diagnosis is likely VIRAL HEPATITIS.

PEARLS: If the ALT is higher than the AST, that is also suggestive of VIRAL HEPATITIS. AST > ALT usually means there is an alcoholic hepatitis. This would only be presented in a teen patient.

ALKALINE PHOSPHATASE

Alkaline phosphatase levels are elevated in biliary and bone disease (e.g., biliary obstruction, bony tumors/metastases).

PEARL: A Gamma-Glutamyl Transpeptidase (GGT) level will guide you to the source of an elevated alkaline phosphatase. GGT is elevated in hepatic disease. It is normal in diseases of the bone.

BILIARY OBSTRUCTION

After a biliary obstruction, AST becomes elevated first, followed by alkaline phosphatase.

CAUSES OF JAUNDICE

Jaundice may be due to hyperbilirubinemia from common neonatal jaundice etiologies (discussed in the Neonatology section), hemolytic jaundice (discussed in the Hematology section), or liver or biliary diseases (discussed in this chapter).

PEARL: When evaluating a patient with jaundice, if a hepatobiliary etiology is suspected, look at the transaminase and alkaline phosphatase levels to help differentiate CHOLESTATIC DISEASE from HEPATOCELLULAR JAUNDICE. In hepatocellular jaundice, there will be an associated transaminitis. In cholestatic jaundice, there will be a marked elevation in alkaline phosphatase.

CHOLESTASIS

Cholestasis may present in the neonatal period. Look for possible acholic (pale or gray) stools, hepatomegaly, and an elevation in the DIRECT (or CONJUGATED) bilirubin. A HIDA scan will show hepatic uptake without biliary excretion due to an obstructive process.

BILIARY ATRESIA

In cases of biliary atresia, initially look for an elevation in the direct bilirubin (AKA conjugated bilirubin) in a neonate. If found, obtain an abdominal ultrasound followed by a HIDA scan. If left untreated, this can result in liver failure. Until the liver fails, conjugation of bilirubin continues. KERNICTERUS only occurs once the liver fails and indirect bilirubin (AKA unconjugated bilirubin) can no longer be conjugated (only unconjugated bilirubin can cross the blood-brain barrier). Later in the course of the disease, indirect bilirubin (AKA unconjugated bilirubin) will also be elevated if left untreated.

 CHOLEDOCHAL CYSTS

Choledochal cysts are congenital cystic dilations of the biliary tree. Along with jaundice, other symptoms may include an abdominal mass, RUQ abdominal pain, nausea, vomiting, and pancreatitis. These patients carry an increased risk of cancer. Treatment is surgical removal of the cyst.

IMAGE: (Various types of choledochal cysts) www.pbrlinks.com/CHOLEDOCHAL1