Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (194 page)

   
Hematology
: Marked increase in WBC (≤30,000/μL) with increase in granulocytes

   Core laboratory: Increased serum AST and ALT. Increased urine urobilinogen

Considerations

   Laboratory findings of incomplete duct obstruction due to inflammation or of preceding complete duct obstruction (e.g., stone, tumor, scar). See Choledocholithiasis

   Laboratory findings of parenchymal cell necrosis and malfunction

CHOLANGITIS, PRIMARY SCLEROSING

   Chronic fibrosing cholestatic inflammation of intra- and extrahepatic bile ducts predominantly in men younger than age 45; rare in pediatric patients; ≤75% are associated with IBD, especially UC. Slow, relentless, progressive course of chronic cholestasis to death (usually from liver failure). Twenty-five percent of patients are asymptomatic at the time of diagnosis.

   Diagnostic Criteria

1.   Cholestatic biochemical profile for >6 months

   Serum ALP may fluctuate but is always increased (usually ≥3 times upper limit of normal).

   Serum GGT is increased.

   Serum AST is mildly increased in >90%. ALT > AST in three fourths of cases.

   Serum bilirubin is increased in 50% of patients; occasionally is very high; may fluctuate markedly; gradually increases as disease progresses. Persistent value >1.5 mg/dL is a poor prognostic sign that may indicate irreversible medically untreatable disease.

2.   Compatible clinical history (e.g., IBD) and exclusion of other causes of sclerosing cholangitis (e.g., previous bile duct surgery, gallstones, suppurative cholangitis, bile duct tumor or damage due to floxuridine, AIDS, congenital duct anomalies)

3.   Characteristic cholangiogram to distinguish from primary biliary cirrhosis

   Increased γ-globulin in 30% and increased IgM in 40–50% of cases

   Antineutrophil cytoplasmic antibody (ANCA) is present in approximately 65% of cases, and antinuclear antibodies are noted in <35% of cases and are present at higher levels than in other liver diseases, but diagnostic significance is not yet known.