PBC & PSC.
Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are chronic autoimmune diseases affecting the bile ducts.
They are important causes of cholestatic LFTs, chronic liver disease, and cirrhosis.
This guide focuses on when to suspect them, how to investigate, and what doctors should do in everyday NHS practice.
🟣 Big Picture First
If you remember one thing:
Raised ALP out of proportion to ALT → think cholestasis → think PBC or PSC.
Most referrals for these conditions start with:
“Persistently raised ALP”.
What are PBC and PSC?
Primary Biliary Cholangitis (PBC)
- Autoimmune destruction of small intrahepatic bile ducts
- Slow, progressive
- Often treatable
Primary Sclerosing Cholangitis (PSC)
- Inflammation and fibrosis of large bile ducts
- Causes strictures and obstruction
- Associated with IBD
- Higher cancer risk
Simple way to think:
- PBC → small ducts
- PSC → large ducts
🟡 Primary Biliary Cholangitis (PBC)
How does PBC present?
Typical patient:
- Middle-aged woman
- Incidental abnormal LFTs
Common features:
- Fatigue
- Pruritus
- Dry eyes/mouth
- Mild jaundice (later)
Often:
Completely asymptomatic
Classic blood test pattern
- Raised ALP (main abnormality)
- Mild ALT/AST rise
- Positive AMA (anti-mitochondrial antibody)
- Raised IgM
This pattern is very characteristic.
On the ward/clinic, always ask
Middle-aged woman + isolated raised ALP → could this be PBC?
Key investigations
- AMA
- IgM
- Ultrasound liver (exclude obstruction)
- Fibrosis assessment (FibroScan)
Often:
- AMA positive + cholestatic LFTs = diagnosis
Biopsy rarely needed.
Management (specialist-led)
Main treatment:
- Ursodeoxycholic acid (UDCA)
This:
- Slows progression
- Improves survival
Early treatment matters.
Complications to watch for
- Cirrhosis
- Portal hypertension
- Osteoporosis
- Fat-soluble vitamin deficiency
🟢 Primary Sclerosing Cholangitis (PSC)
How does PSC present?
Typical patient:
- Younger male
- History of IBD (especially ulcerative colitis)
Presentations:
- Abnormal LFTs
- Pruritus
- Recurrent cholangitis
- Jaundice
- Fatigue
Sometimes:
- Found incidentally during IBD workup
Classic blood test pattern
- Raised ALP
- Mild ALT/AST rise
- Usually autoantibodies negative
If AMA negative + cholestatic LFTs → think PSC or obstruction.
On the ward/clinic, always ask
Does this patient have IBD?
Because:
PSC + ulcerative colitis is a very strong association
Key investigations
- MRCP → shows bile duct strictures/beading
- Ultrasound
- Fibrosis assessment
MRCP is diagnostic in most cases.
Biopsy sometimes needed for small-duct PSC.
Management (real-world NHS practice)
No curative medication.
Management focuses on:
- Treating complications
- Managing strictures (ERCP)
- Treating cholangitis
- Cancer surveillance
- Transplant referral in advanced disease
Unlike PBC:
UDCA has limited benefit
Important complications
PSC patients are high risk for:
- Recurrent cholangitis
- Cirrhosis
- Cholangiocarcinoma
- Colorectal cancer (if IBD)
These patients need specialist follow-up.
🔴 First priority = exclude obstruction
Before diagnosing PBC or PSC:
Always rule out:
- Gallstones
- Malignancy
- Biliary obstruction
Do ultrasound first.
Never label autoimmune disease before excluding mechanical causes.
Immediate management on the ward (what juniors should actually do)
If you find cholestatic LFTs:
Do:
- Review medications
- Alcohol history
- Ultrasound liver
- Autoimmune screen (AMA, ANA, etc.)
- Refer hepatology
If patient is unwell with fever/jaundice:
→ think cholangitis → treat urgently (antibiotics + escalate)
When to escalate
Urgent senior review if:
- Fever + jaundice
- Suspected cholangitis
- Rising bilirubin
- New confusion
- Decompensated cirrhosis
- NEWS ≥5
These may need:
- ERCP
- HDU/ICU
- Urgent specialist input
Common mistakes juniors make
- Ignoring isolated ALP rise
- Not checking AMA
- Forgetting PSC–IBD association
- Labelling everything as “fatty liver”
- Missing cholangitis
- Not referring early
Take-home concept
Cholestatic LFTs are not “mild abnormalities.”
Think structurally: obstruction vs autoimmune.
Diagnose early, refer early, and prevent progression.