Primary sclerosing cholangitis with normal serum alkaline phosphatase activity

Area of Science:

• Hepatology
• Gastroenterology
• Internal Medicine

Background:

• Primary sclerosing cholangitis (PSC) is a chronic liver disease.
• Elevated serum alkaline phosphatase (ALP) is a common diagnostic marker for PSC.
• The presentation of PSC with normal ALP is not well-characterized.

Purpose of the Study:

• To investigate the occurrence and characteristics of PSC in patients with normal serum ALP.
• To determine if advanced liver disease can be present in PSC without elevated ALP.
• To assess the implications for PSC diagnosis in patients with inflammatory bowel disease (IBD).

Main Methods:

• Retrospective case series of 12 patients with confirmed PSC via cholangiography.
• Analysis of serum ALP levels at diagnosis and during follow-up.
• Histological and cholangiographic assessments were correlated with ALP levels.

Main Results:

• 12 cases of PSC with normal serum ALP were identified.
• In 7 patients, ALP remained normal throughout follow-up; in 5, it fluctuated (normalized in 4).
• Four patients had advanced fibrosis/cirrhosis and significant cholangiographic changes despite normal ALP, confirming occult PSC is possible.

Conclusions:

• PSC can manifest with normal serum ALP, even in cirrhotic stages.
• The findings suggest PSC may be underdiagnosed, especially in IBD patients.
• Normal ALP should not exclude PSC investigation in symptomatic IBD patients with suspected liver disease.