Autoimmune Liver Diseases

Autoimmune liver diseases (AILDs) are immune-mediated conditions affecting hepatocytes and/or the biliary epithelium. They share a predilection for women (with the exception of primary sclerosing cholangitis [PSC]), overlap with systemic autoimmune disease, and can progress to cirrhosis if untreated. The three entities differ fundamentally in target cell, injury pattern, autoantibody profile, and treatment.

Same organ, three different targets along the hepatocyte-to-duct axis

Disease	Primary Target	Injury Pattern	Key Autoantibody	Predominant Sex
Autoimmune Hepatitis (AIH)	Hepatocytes	Hepatocellular — elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST)	Antinuclear antibody (ANA), anti-smooth muscle antibody (ASMA), anti-liver-kidney microsomal-1 (anti-LKM-1)	Female (~70%)
Primary Biliary Cholangitis (PBC)	Intrahepatic small bile ducts	Cholestatic — elevated alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT)	Anti-mitochondrial antibody (AMA-M2), anti-sp100, anti-gp210	Female (~95%)
Primary Sclerosing Cholangitis (PSC)	Intra- and extrahepatic bile ducts	Cholestatic — ALP elevation; fluctuates	pANCA (non-specific)	Male (~60–70%)

Quick recall

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What injury pattern does AIH produce, and which immunoglobulin is characteristically elevated?

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AIH is an immune-mediated hepatocellular injury driven by T-cell–mediated attack on hepatocytes. It presents across a wide age range — peaks in young women and again in perimenopause — with a spectrum ranging from mild chronic hepatitis to acute liver failure. Without treatment, it progresses to cirrhosis in the majority of cases.

Diagnosis

The injury pattern is hepatocellular: elevated ALT and AST (often markedly so), elevated immunoglobulin G (IgG), and circulating autoantibodies. Bilirubin and ALP may be elevated but are not the dominant abnormality.

Liver Biopsy Requirement

Liver biopsy is usually required. Unlike most chronic liver diseases where diagnosis is clinical, AIH often mandates histologic confirmation — interface hepatitis, plasma cell infiltration, and hepatocyte rosette formation are the hallmarks. Biopsy also establishes fibrosis stage and is recommended before stopping therapy.

Simplified Diagnostic Criteria (Hennes 2008)

Points are assigned across four domains. For tiered parameters (e.g., ANA/ASMA at 1:40 vs. 1:80), assign the highest applicable score — they are not additive. Check all parameters you have data for, then review the scoring logic below. ≥6 = Probable AIH. ≥7 = Definite AIH.

ANA or ASMA ≥1:80 — +2 pts

Note: ≥1:40 = +1 pt. Use highest applicable tier — not additive.

+2 pts

Anti-LKM-1 ≥1:40 — +2 pts

Anti-liver-kidney microsomal antibody type 1. Positive at ≥1:40 titer.

+2 pts

Anti-SLA positive — +2 pts

Anti-soluble liver antigen. Any positive result scores +2.

+2 pts

IgG >1.1× ULN — +2 pts

Note: >ULN = +1 pt. Use highest applicable tier — not additive.

+2 pts

Liver histology: typical of AIH — +2 pts

Interface hepatitis, plasma cell infiltrate, hepatocyte rosettes. Compatible = +1 pt.

+2 pts

Viral hepatitis excluded — +2 pts

Negative hepatitis A, B, and C serologies. Required criterion.

+2 pts

0 of 6 complete

Score	Interpretation
≥7 points	Definite AIH — initiate treatment
≥6 points	Probable AIH — liver biopsy recommended to confirm; initiate treatment if histology typical
<6 points	Insufficient for AIH diagnosis — consider alternative diagnoses

AIH type 1 (ANA/ASMA-positive) is most common. AIH type 2 (anti-LKM-1-positive) is less common, predominantly in children and young women.

Treatment

Induction — First-Line

Prednisone + Azathioprine

Prednisone 40–60 mg/day with taper over 4 weeks + azathioprine 50 mg/day (titrate to 1–2 mg/kg/day)
Combination allows lower steroid doses and reduces steroid-related side effects
Prednisone monotherapy acceptable initially; azathioprine not used alone for induction

Induction — Steroid-Sparing Alternative

Budesonide 9 mg/day

3 mg TID — high first-pass hepatic metabolism reduces systemic effects
Non-cirrhotic patients only — portosystemic shunting in cirrhosis bypasses first-pass effect
Avoid in cirrhosis: negates selectivity advantage; increased portal vein thrombosis risk

Maintenance

Azathioprine Monotherapy

Azathioprine 1–2 mg/kg/day after achieving remission
Steroids tapered off over 1–2 years
Long-term maintenance often required — relapse rate after stopping: 50–80%

Monitoring

Labs During Treatment

ALT, AST, IgG every 4–8 weeks (induction); every 3–6 months (stable remission)
CBC for azathioprine myelosuppression; LFTs for hepatotoxicity
Azathioprine metabolites (6-TG, 6-MMP) can assess therapeutic levels and toxicity

Stopping Treatment

When to Withdraw

Minimum 2–3 years of steroid-free biochemical remission
Liver biopsy recommended before stopping — histologic remission advised
Relapse rate 50–80% after stopping

Second-Line

Mycophenolate Mofetil (MMF)

1 g BID — for azathioprine intolerance or non-response
Preferred second-line option in most centers
Monitor for GI side effects and cytopenias

Third-Line

Tacrolimus / Cyclosporine

Calcineurin inhibitors — third-line in specialist centers
Used for refractory AIH not responding to MMF
Requires transplant hepatology expertise for monitoring

TPMT Safety Check

Check thiopurine methyltransferase (TPMT) before azathioprine: TPMT genotype or enzyme activity testing is essential prior to initiating azathioprine. Patients with absent or low TPMT activity are at risk for severe, potentially fatal myelosuppression from azathioprine accumulation. Dose reduction or alternative therapy (e.g., MMF) is required in deficient patients.

PBC is a chronic cholestatic liver disease caused by immune-mediated destruction of intrahepatic small bile ducts. It affects women almost exclusively (~95%) and often presents insidiously with fatigue and pruritus, or is detected on routine labs as an isolated ALP elevation. Without treatment it progresses through fibrosis to cirrhosis over years to decades.

Diagnosis

PBC is diagnosed when 2 of the following 3 criteria are met:

Diagnostic Criteria — 2 of 3 Required

ALP elevation ≥1.5× ULN
Anti-mitochondrial antibody (AMA-M2) positive (titer ≥1:40; sensitivity >95%, specificity >98%)
Liver biopsy showing florid bile duct lesion (granulomatous cholangitis) — not required when AMA is positive

AMA-Negative PBC (~5–10%)

In AMA-negative cases, diagnosis requires anti-sp100 or anti-gp210 antibodies (PBC-specific antinuclear antibodies) in combination with a compatible cholestatic biochemical pattern. Liver biopsy is often needed in this setting.

Associated Features and Complications

Fatigue — most common symptom; not correlated with disease stage and has no effective pharmacotherapy
Pruritus — cholestatic itch; severity varies and does not track with bilirubin
Fat-soluble vitamin deficiencies (A, D, E, K) from impaired bile-dependent absorption
Metabolic bone disease (osteoporosis) — screen with DEXA
Sicca syndrome (dry eyes, dry mouth) — association with Sjögren syndrome

First-Line Treatment

UDCA — First-Line

Ursodeoxycholic acid (UDCA) 13–15 mg/kg/day — start at diagnosis, continue lifelong. Improves biochemical markers, delays histologic progression, and improves transplant-free survival. Approximately 40% of patients have an inadequate biochemical response and require second-line therapy.

Biochemical Response Target at 1 Year

Toronto Criteria

Target: ALP <1.67× ULN at 1 year on UDCA (Toronto criteria; Murillo Perez et al.). Failure to achieve this threshold indicates inadequate response and is the primary indication for second-line therapy. Normal bilirubin and albumin should also be maintained — rising bilirubin is the most important prognostic marker of disease progression.

Second-Line Therapies

Agent	Status	Mechanism	Dose	Notes
Elafibranor (Iqirvo)	FDA 2024	PPAR-α/δ dual agonist	80 mg/day	Approved June 2024 (ELATIVE trial); reduces ALP and bilirubin; may also improve fatigue; well tolerated; avoid in pregnancy
Seladelpar (Livdelzi)	FDA 2024	PPAR-δ agonist	10 mg/day	Approved August 2024 (RESPONSE trial); reduces ALP and bilirubin; also improves pruritus; avoid in pregnancy
Obeticholic acid (OCA, Ocaliva)	Voluntarily withdrawn (US)	Farnesoid X receptor (FXR) agonist	5 mg/day, titrate to 10 mg/day	Voluntarily withdrawn from the US market. Previously used for inadequate UDCA response. Worsened pruritus; contraindicated in decompensated cirrhosis.
Bezafibrate	Not US approved	PPAR-α agonist	400 mg/day	Not available in the US; widely used in Europe and Japan; BEZURSO trial demonstrated biochemical and histologic benefit
Fenofibrate	Off-label (US)	PPAR-α agonist	145–160 mg/day	Used in the US as an off-label bezafibrate alternative; less trial data in PBC

Symptom Management — Pruritus

Cholestatic pruritus is a major driver of impaired quality of life in PBC. Management follows a stepwise approach per AASLD guidelines:

Step 1

Non-Pharmacological

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Step 2 — First Drug

Cholestyramine

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Step 3 — Subsequent Options

Rifampicin · Naltrexone · Sertraline

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Fatigue in PBC

The most common symptom and has no effective pharmacological treatment. Before attributing fatigue to PBC, exclude reversible causes: hypothyroidism (common co-morbidity), anemia, obstructive sleep apnea, and depression.

Surveillance

If cirrhosis develops: hepatocellular carcinoma (HCC) surveillance with ultrasound ± alpha-fetoprotein (AFP) every 6 months. Monitor ALP and bilirubin trajectory at each visit — bilirubin trend is the most important prognostic indicator.

PSC is a chronic cholestatic liver disease characterized by progressive inflammation and fibrosis of the intra- and extrahepatic bile ducts, leading to multifocal strictures, biliary obstruction, and eventually cirrhosis. Unlike AIH and PBC, PSC predominantly affects men (~60–70%) and is strongly associated with inflammatory bowel disease (IBD). There is no proven disease-modifying pharmacotherapy.

Diagnosis

The biochemical pattern is cholestatic — ALP elevation that may fluctuate (a fluctuating ALP is characteristic and should not be misinterpreted as improvement). Transaminases are mildly elevated. Bilirubin rises with progression or a relevant stricture (see below).

MRCP — Beaded Appearance

MRCP is the first-line diagnostic imaging modality. Characteristic finding: multifocal biliary strictures alternating with normal or dilated segments — the "beaded appearance" involving intra- and/or extrahepatic bile ducts. MRCP sensitivity ~80%, specificity ~87% compared to ERCP as gold standard. ERCP is reserved for therapeutic intervention (stricture dilation, tissue sampling) rather than initial diagnosis.

Associations and Variants

IBD Association

PSC-IBD

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Overlap Syndrome

PSC-AIH Overlap

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Variant

Small-Duct PSC

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Treatment

No proven disease-modifying medical therapy exists for PSC. Management focuses on complication surveillance, endoscopic management of relevant strictures, and transplant evaluation for end-stage disease.

UDCA in PSC — Avoid High Doses

Standard-dose UDCA (13–15 mg/kg/day) shows no benefit on transplant-free survival in PSC. High-dose UDCA (28–30 mg/kg/day) is associated with increased mortality, colorectal cancer risk, and need for liver transplantation — demonstrated in the Mayo Clinic trial (Lindor 2009). High-dose UDCA should not be used. The role of standard-dose UDCA remains debated; most guidelines do not recommend it for PSC outside of symptomatic management in select cases.

Relevant Stricture Management

The AASLD 2022 guidance replaced the older term dominant stricture with relevant stricture, defined as any stricture of the common hepatic duct or hepatic ducts accompanied by signs or symptoms of obstructive cholestasis and/or bacterial cholangitis — i.e. the stricture must be clinically consequential, not merely narrow on imaging.

Endoscopic balloon dilation at ERCP is the preferred approach. Stenting is reserved as a short-term bridge. Every relevant stricture evaluation should include brush cytology and intraductal biopsy to exclude cholangiocarcinoma (CCA).

Cancer Surveillance

Cancer	Risk	Surveillance	Action
Cholangiocarcinoma (CCA)	Lifetime risk 10–15% (vs. 0.01–0.02% general population)	Annual MRCP + serum CA 19-9	CA 19-9 >129 U/mL or a new relevant stricture → urgent ERCP with brush cytology + FISH
Gallbladder Cancer	Significantly elevated; gallbladder polyps carry high malignant potential	Annual ultrasound	Cholecystectomy for polyps ≥8 mm (lower threshold than general population ≥10 mm); any gallbladder mass → urgent surgical evaluation
Colorectal Cancer (CRC)	PSC-IBD: ~14% cumulative incidence at 10 years from PSC diagnosis	Annual or biennial colonoscopy (PSC-IBD); every 3–5 years if no IBD	Ongoing surveillance required even after colectomy for UC in PSC

Liver Transplantation

Liver transplantation is the definitive treatment for end-stage PSC, with excellent outcomes (5-year patient survival >80%). Listing is MELD-based; exception points may be granted for recurrent bacterial cholangitis. PSC recurs in the transplanted liver in ~20–25% of cases. CCA is generally a contraindication to transplant at most centers, though select patients with perihilar CCA meeting specific criteria (Mayo Protocol) may be eligible at specialized centers.