Internal Medicine

0521779407-C04 CUNY1086/Karliner 0 521 77940 7 June 14, 2007 20:37

450 Cystic Fibrosis

tests

Basic Tests: Blood

■Early disease: liver biochemistry intermittently abnormal, with 41%

prevalence at 12 years of age

■Advanced disease: low albumin, elevated bilirubin and INR

Specific Diagnostic Tests

■Sweat chloride test: low chloride concentration

■Genetic test: no specific gene mutation occurs more frequently in

patients with liver disease

Imaging

■Ultrasound: nodular, coarse liver in biliary cirrhosis, or increased

echogenicity in hepatic steatosis; gallstones in up to 25%; micro-

gallbladder in up to 20%

■Cholangiogram: focal biliary stricturing and dilatation

Liver Biopsy

■Significant sampling error can occur due to patchy fibrosis; focal

biliary cirrhosis often seen, leading to multilobular biliary cirrhosis in

10%; may see giant cells, bile plugs, or bile duct proliferation among

the 30% with neonatal cholestasis

differential diagnosis

■Neonates & infants: neonatal (giant cell) hepatitis, TORCH (toxo-

plasma, rubella, cytomegalovirus, herpes virus), syndromic/non-

syndromic bile duct paucity, extrahepatic biliary atresia, chole-

dochal cyst, neonatal sclerosing cholangitis, alpha-1-antitrypsin

deficiency, tyrosinemia, Gaucher’s disease, Niemann-Pick disease,

galactosemia, fructosemia, hypothyroidism, Crigler-Najjar syn-

dromes

■Adults: primary biliary cirrhosis, primary sclerosing cholangitis,

choledochal cyst, cholangiocarcinoma, ampullary neoplasm, pan-

creatic neoplasm

management

What to Do First

■Assess severity of liver disease and complications: history of meco-

nium ileus and pancreatic insufficiency may be predictive of devel-

opment of liver disease, which predominantly occurs in first decade

of life

■Determine candidacy for therapy