Revised Original International Autoimmune Hepatitis Score (IAIHG)
The revised original scoring system from the International Autoimmune Hepatitis Group (IAIHG) for diagnosing autoimmune hepatitis (AIH). Unlike the simplified score (which is point-of-care), the revised original score uses detailed serological, histological, and treatment response data. Pre-treatment score above 15 = definite AIH; 10-15 = probable AIH. Developed by Alvarez et al. 1999.
Score interpretation
IAIHG score above 15 -- definite autoimmune hepatitis
→ Initiate AIH treatment: prednisolone 30-40 mg/day reducing regimen OR combination prednisolone 30 mg/day plus azathioprine 50 mg/day (preferred as steroid-sparing); monitor LFTs weekly for first 4 weeks; aim for remission (ALT/AST within normal range, IgG normalised, histological resolution); if complete remission at 2 years: consider gradual withdrawal (high relapse risk -- discuss with patient); if relapse: re-treat; check TPMT genotype before starting azathioprine (to identify poor metabolisers at risk of bone marrow toxicity); vaccinations before immunosuppression: hepatitis A, B, pneumococcal, influenza; hepatology specialist care.
IAIHG score 10-15 -- probable autoimmune hepatitis; consider treatment trial
→ Discuss with hepatologist; confirm with liver biopsy if not done; repeat serology (ANA, SMA, anti-LKM-1, anti-SLA, IgG) if seronegative; exclude drug-induced liver injury (DILI) -- review medication list carefully; exclude viral hepatitis (EBV, CMV if standard serology negative); exclude PBC/PSC overlap (AMA, MRCP/ERCP if cholestatic features); if probable AIH confirmed: treatment trial with prednisolone; assess response at 2-4 weeks (LFTs); if response: continue treatment as per definite AIH protocol; if no response: reconsider diagnosis.
IAIHG score below 10 -- autoimmune hepatitis unlikely with this scoring system
→ AIH diagnosis unlikely with revised original scoring; review alternative diagnoses: drug-induced liver injury (DILI -- use RUCAM/Roussel Uclaf Causality Assessment), viral hepatitis, Wilson disease (serum copper, caeruloplasmin, 24h urine copper, slit lamp for KF rings -- especially young patients), ALD, NAFLD, PBC (AMA, GGT, ALP), PSC (MRCP), haemochromatosis (ferritin, transferrin saturation, HFE gene); hepatology or specialist referral; liver biopsy if diagnosis remains unclear; document alternative diagnosis workup in notes.
Interpretation bands for the IAIHG AIH Score. Apply clinical judgement and local guidance.
References
- Alvarez F et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31(5):929-938.
- EASL Clinical Practice Guidelines: Autoimmune Hepatitis. J Hepatol. 2015;63(4):971-1004.
Related
Curated clinical cross-links plus same-class fallbacks.
- Azathioprine · Systemic Immunosuppressant — Eczema / Autoimmune Dermatoses
- Natalizumab · Disease-Modifying Therapy — MS (Anti-VLA-4 Monoclonal Antibody)
- Prednisolone (Rheumatology) · Corticosteroid (oral) — bridge/anti-inflammatory
- Inebilizumab (Anti-CD19 — IgG4-Related Disease) · Anti-CD19 Monoclonal Antibody (B-Cell Depleting)
- Trimetazidine · Metabolic Anti-Anginal
- Isotretinoin · Systemic retinoid (Vitamin A derivative) / Anti-acne
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.