About the Simplified Criteria for the Diagnosis of Autoimmune Hepatitis
Four parameters, maximum 8 points: autoantibodies (up to 2), serum IgG (up to 2), liver histology (up to 2) and exclusion of viral hepatitis (2). A score of 6 or above is probable autoimmune hepatitis and 7 or above is definite, with roughly 88% sensitivity and 97% specificity at the ≥6 cut-off. Two things catch people out. The autoantibody row is capped at 2 points however many antibodies are positive — they do not add up. And the maximum achievable without liver histology is 6, so a definite diagnosis is unreachable without a biopsy.
Formula
Score = autoantibodies (0–2) + IgG (0–2) + histology (0–2) + absence of viral hepatitis (0 or 2)
Maximum 8 · probable ≥ 6 · definite ≥ 7- Autoantibodies
- ANA or SMA 1:40 → 1. ANA or SMA ≥ 1:80, or LKM-1 ≥ 1:40, or SLA/LP positive → 2. Capped at 2 in total.
- IgG
- > upper limit of normal → 1. > 1.10 × upper limit of normal → 2.
- Histology
- Compatible → 1. Typical → 2.
- Absence of viral hepatitis
- Excluded → 2. Present or not excluded → 0.
- The autoantibody row is capped at 2 points regardless of how many antibodies are positive. A patient with a high-titre ANA, a positive SMA and a positive anti-SLA/LP scores 2, not 6 — this is the commonest way the score gets inflated.
- Without liver histology the maximum is 6, which reaches probable but never definite. Biopsy is effectively required for a definite diagnosis.
- Absence of viral hepatitis is worth 2 points, the same as the strongest autoantibody finding. That reflects how strongly the exclusion contributes, and it assumes the exclusion was actually done.
- The IgG threshold for 2 points is 1.10 × the upper limit of normal in the published table. Some secondary reproductions state 1.3; the lower figure is the original.
- A score below 6 does not exclude autoimmune hepatitis. The simplified criteria were built for specificity and miss atypical and seronegative presentations, where the revised original score performs better.
Interpreting the result
A score of 7 or 8 is a confident diagnosis. At the ≥6 threshold the criteria run around 88% sensitivity and 97% specificity, and specificity rises further at 7, so a definite result should be acted on rather than re-examined. A score of exactly 6 deserves a specific question: was a biopsy done? Because 6 is the ceiling without histology, a probable score in a patient who has not been biopsied may well become definite once tissue is available, and the biopsy also stages fibrosis and can reveal an alternative diagnosis. Below 6, the important point is what the result does not mean. The simplified criteria were optimised for specificity in routine practice and are known to miss atypical presentations, seronegative disease, and cases where anti-SLA/LP was never requested. A negative simplified score with persistent clinical suspicion is an indication to apply the revised original score, not to abandon the diagnosis.
| Score | Band | What it means | Action |
|---|---|---|---|
| ≥ 7 | Definite autoimmune hepatitis | High specificity — around 97% at the ≥6 cut-off, rising further at 7 | Treat as autoimmune hepatitis; consider corticosteroids with or without azathioprine, weighing histological activity against comorbidity |
| 6 | Probable autoimmune hepatitis | Meets the probable threshold, with about 88% sensitivity and 97% specificity at this cut-off | Obtain histology if not already done — 6 is the ceiling without it, and a biopsy may move this to definite |
| < 6 | Criteria not met | Does not exclude autoimmune hepatitis — the simplified criteria miss atypical and seronegative presentations | Apply the revised original IAIHG score, which is more sensitive; check that anti-SLA/LP was tested |
What the Simplified AIH Criteria needs (4 inputs)
- Autoantibodies
- ANA or SMA at 1:40 scores 1. ANA or SMA at 1:80 or above, or anti-LKM-1 at 1:40 or above, or a positive anti-SLA/LP scores 2. The maximum for all autoantibodies combined is 2 — they do not accumulate.
- Serum IgG
- Above the upper limit of normal scores 1; above 1.10 times the upper limit scores 2. The 1.10 multiplier is the published figure, though a few secondary sources render it as 1.3.
- Liver histology
- Compatible with autoimmune hepatitis scores 1; typical of autoimmune hepatitis scores 2. Typical requires interface hepatitis, a lymphocytic or lymphoplasmacytic infiltrate extending into the lobule, and emperipolesis or hepatocellular rosetting.
- Absence of viral hepatitis
- Scores 2 — as much as a strongly positive autoantibody titre. This assumes viral hepatitis has actually been excluded by serology rather than merely considered unlikely.
What it returns
- Total score
- 0 to 8. Probable autoimmune hepatitis at 6, definite at 7 or above.
- Diagnostic category
- Definite, probable, or criteria not met.
- Item breakdown
- Each parameter's contribution, which matters because the histology row is often the difference between probable and definite.
How it is calculated
The simplified criteria are a deliberate reduction of the revised original score rather than a new construct. Hennes and colleagues, working within the International Autoimmune Hepatitis Group, tested which of the original parameters retained independent diagnostic value and found the answer was four: autoantibodies, immunoglobulin G, liver histology and the exclusion of viral hepatitis. Each captures a different pillar of the diagnosis — the autoimmune serology, the humoral response, the tissue pattern, and the exclusion of the main mimic — which is why they are weighted almost equally at 2 points each rather than being fitted with regression coefficients. Capping the autoantibody row at 2 encodes a real clinical observation: multiple positive autoantibodies indicate autoimmunity, but a second or third positive antibody adds little diagnostic information beyond the first, so allowing them to accumulate would overstate the evidence.
Facts & figures
| Parameter | Finding | Points |
|---|---|---|
| Autoantibodies | ANA or SMA at 1:40 | 1 |
| ANA or SMA ≥ 1:80, or LKM-1 ≥ 1:40, or SLA/LP positive | 2 | |
| Serum IgG | > upper limit of normal | 1 |
| > 1.10 × upper limit of normal | 2 | |
| Liver histology | Compatible with AIH | 1 |
| Typical of AIH | 2 | |
| Absence of viral hepatitis | Viral hepatitis excluded | 2 |
Maximum 8. The autoantibody rows are alternatives, not additions — the most that section can contribute is 2 points however many antibodies are positive.
| Simplified (2008) | Revised original (1999) | |
|---|---|---|
| Parameters | 4 | 13, plus optional items |
| Maximum score | 8 | Around 25 depending on optional items |
| Thresholds | Probable ≥ 6, definite ≥ 7 | Pre-treatment: probable 10–15, definite > 15 |
| Built for | Routine clinical practice | Case definition in research |
| Relative strength | Specificity — about 97% | Sensitivity, particularly in atypical cases |
| Needs histology? | For a definite diagnosis, yes | Contributes heavily but the score functions without it |
They are complements rather than competitors: the simplified score first, the revised original when the simplified score falls short but suspicion persists.
Evidence
Derivation — Hennes et al., International Autoimmune Hepatitis Group
2008Development of simplified diagnostic criteria within the International Autoimmune Hepatitis Group, testing which parameters from the revised original score retained independent diagnostic value, and validating the resulting four-parameter score against clinical diagnosis.
At a cut-off of ≥6 the criteria achieved approximately 88% sensitivity and 97% specificity for autoimmune hepatitis, with ≥7 defining definite disease. Total possible score 8, with autoantibodies capped at 2 points.
AASLD practice guidance
2020The 2019 AASLD practice guidance and guidelines on the diagnosis and management of autoimmune hepatitis in adults and children.
Endorses the simplified criteria for routine diagnosis while noting that the revised original score retains a role in atypical presentations and in research settings.
EASL clinical practice guidelines
2015EASL clinical practice guidelines on autoimmune hepatitis.
Recommends the simplified criteria for clinical use, with the revised original score where the presentation does not fit the typical pattern.
Paediatric validation and modification
2012Validation of the simplified criteria in children, where autoimmune sclerosing cholangitis overlaps clinically with autoimmune hepatitis.
Confirmed reasonable performance in children while showing reduced sensitivity in autoimmune sclerosing cholangitis, supporting modification and the use of cholangiography in paediatric presentations.
How it compares
Simplified AIH Criteria vs Revised original IAIHG score
Use the simplified score first and the revised original when it falls short — the first is more specific, the second more sensitive.
The revised original score has thirteen parameters plus optional items and was built for case definition in research; the simplified score has four and was built for the clinic. The trade is specificity for sensitivity. The revised original also contains terms the simplified score lacks entirely — notably a drug history penalty and an AMA penalty — which is why it performs better in atypical, seronegative and overlap presentations. Applying both is reasonable when the answer matters and they disagree.
Simplified AIH Criteria vs RUCAM
Frequently needed together — drug-induced liver injury is the principal mimic of autoimmune hepatitis, and this score has no drug term at all.
A number of drugs, including nitrofurantoin, minocycline and infliximab, produce a syndrome indistinguishable from autoimmune hepatitis on serology and histology. The simplified criteria will happily score such a case at 7. RUCAM assesses whether a drug explains the injury, and a high RUCAM score in a patient who also meets AIH criteria is a strong argument for drug-induced liver injury with autoimmune features rather than for primary autoimmune hepatitis.
Simplified AIH Criteria vs Child-Pugh score
Different questions entirely — this score diagnoses autoimmune hepatitis, Child-Pugh grades the severity of established cirrhosis.
The simplified criteria say nothing about severity, fibrosis stage or prognosis. A patient can score 8 with minimal fibrosis or with established cirrhosis. Once the diagnosis is made, staging comes from histology and from the usual liver severity measures.
Pearls & pitfalls
- The autoantibody row caps at 2 points. Multiple positive antibodies do not accumulate, and treating them as additive is the commonest way this score is inflated.
- The maximum without histology is 6. A definite diagnosis is unreachable without a biopsy, which is the practical argument for obtaining one.
- Absence of viral hepatitis is worth 2 points and assumes the exclusion was actually performed with serology — not simply that viral hepatitis seemed unlikely.
- Test anti-SLA/LP explicitly. It is highly specific for autoimmune hepatitis, worth a full 2 points, and frequently omitted from first-line autoimmune panels.
- The IgG multiplier for 2 points is 1.10 × the upper limit of normal. A few secondary sources render this as 1.3; the published figure is the lower one.
- 'Typical' histology is a specific bar — interface hepatitis, a lymphocytic or lymphoplasmacytic infiltrate extending into the lobule, and emperipolesis or rosetting. Anything less is 'compatible' at 1 point.
- A score below 6 does not exclude the diagnosis. Move to the revised original score rather than dismissing the possibility.
- Drug-induced liver injury mimics autoimmune hepatitis closely, including histologically and serologically, and this score has no term for drug exposure at all — the revised original score does.
Critical actions
- Exclude viral hepatitis properly with serology before claiming the 2 points for its absence.
- Obtain liver histology where the diagnosis is being made seriously — it is required for a definite score, stages fibrosis, and may reveal an alternative diagnosis.
- Test the full autoantibody panel including anti-SLA/LP and anti-LKM-1, not only ANA and SMA.
- Take a careful drug and supplement history; drug-induced liver injury is the principal mimic and is not represented in this score.
- Where the score falls below 6 and suspicion persists, apply the revised original IAIHG score rather than stopping.
- Consider overlap with primary biliary cholangitis or primary sclerosing cholangitis where the biochemistry is cholestatic, and arrange cholangiography in children and in adults with a cholestatic pattern.
- Discuss corticosteroids with or without azathioprine once the diagnosis is established, weighing histological activity against comorbidity.
Why this score exists
The interesting decision is the cap on autoantibodies. Left uncapped, a patient with a high-titre ANA, a positive SMA and a positive anti-SLA/LP would score 6 on serology alone and reach probable autoimmune hepatitis without any histology or viral exclusion at all — which is exactly the false-positive the group wanted to avoid, because multiple autoantibodies are common in other liver diseases and in the elderly. Capping the row at 2 encodes the judgement that the second and third positive antibody add far less than the first. The same reasoning explains why exclusion of viral hepatitis is worth a full 2 points despite being a negative finding: in a patient with hepatitis and autoantibodies, ruling out the common cause is genuinely as informative as any positive test.
About the creator
First author, 2008 simplified criteria
Led the derivation of the simplified criteria within the International Autoimmune Hepatitis Group.
Co-author; long-standing contributor to autoimmune hepatitis diagnostic criteria
Co-authored both the revised original and the simplified criteria.
Senior author
Senior author of the simplified criteria and a principal figure in the International Autoimmune Hepatitis Group.
Limitations
- Built for specificity, so it misses atypical presentations — seronegative autoimmune hepatitis, acute severe presentations and overlap syndromes are all under-detected.
- Contains no term for drug exposure, despite drug-induced liver injury being the principal mimic and being scored explicitly in the revised original criteria.
- Requires liver histology for a definite diagnosis, which is not always obtainable in coagulopathic or acutely unwell patients.
- 'Compatible' versus 'typical' histology is a pathologist's judgement, and interobserver agreement on that distinction is imperfect.
- Reduced sensitivity in children, particularly where autoimmune sclerosing cholangitis is present, which cholangiography rather than this score identifies.
- The exclusion of viral hepatitis is worth 2 points but the criteria do not specify which viruses or which tests, leaving the most heavily weighted negative finding loosely defined.
- Derived predominantly in adult populations with typical presentations, which is the group in which any diagnostic score performs best.
If you are the patient
Autoimmune hepatitis is a condition where the immune system attacks the liver. There is no single test that proves it, so doctors add up evidence from four areas: certain antibodies in the blood, the level of an immune protein called IgG, what a liver biopsy shows, and confirmation that viral hepatitis is not the cause. Each area contributes up to 2 points, giving a maximum of 8. Six points means autoimmune hepatitis is probable and seven or more means it is considered definite. One practical point worth knowing: without a liver biopsy the highest possible score is six, so a biopsy is usually needed to be certain — and it also shows how much scarring there is, which affects treatment. If the score comes out below six but the doctors still suspect the condition, there is a longer and more detailed scoring system they can use instead, which picks up unusual presentations this shorter one can miss.
Frequently asked questions
What are the simplified criteria for autoimmune hepatitis?#
A four-parameter score: autoantibodies (up to 2 points), serum IgG (up to 2), liver histology (up to 2) and exclusion of viral hepatitis (2). Maximum 8. A score of 6 or above is probable autoimmune hepatitis and 7 or above is definite.
What score confirms autoimmune hepatitis?#
Seven or above is definite; six is probable. At the ≥6 cut-off the criteria have roughly 88% sensitivity and 97% specificity, and specificity rises further at 7.
Do multiple positive autoantibodies add up?#
No. The autoantibody section is capped at 2 points however many antibodies are positive. A patient with a high-titre ANA, a positive SMA and a positive anti-SLA/LP scores 2 for that section, not 6. Treating them as additive is the commonest error with this score.
Is a liver biopsy required?#
For a definite diagnosis, effectively yes. The maximum achievable without histology is 6, which reaches probable but never definite. A biopsy also stages fibrosis and can reveal an alternative diagnosis, so it is worth obtaining where the diagnosis matters.
Is the IgG threshold 1.10 or 1.3 times the upper limit of normal?#
The published figure in the 2008 criteria is 1.10 times the upper limit of normal for 2 points, with any elevation above the upper limit scoring 1. A small number of secondary reproductions state 1.3; the original is the lower value.
What if the score is below 6 but I still suspect autoimmune hepatitis?#
A negative simplified score does not exclude the diagnosis. Apply the revised original IAIHG score, which is more sensitive in atypical, seronegative and overlap presentations, and check that anti-SLA/LP was actually tested — it is highly specific and frequently omitted.
Can drug-induced liver injury score highly on these criteria?#
Yes, and this is a real weakness. Several drugs produce a syndrome indistinguishable from autoimmune hepatitis on serology and histology, and the simplified criteria contain no term for drug exposure at all. Take a careful drug and supplement history, and consider RUCAM alongside.
Do the simplified criteria work in children?#
They perform reasonably but with reduced sensitivity, particularly where autoimmune sclerosing cholangitis is present — which is common in paediatric autoimmune liver disease and is identified by cholangiography rather than by this score.
References
Original / primary reference
Guidelines
- Mack CL, Adams D, Assis DN, et al. Diagnosis and Management of Autoimmune Hepatitis in Adults and Children: 2019 Practice Guidance and Guidelines from the American Association for the Study of Liver Diseases. Hepatology. 2020;72(2):671-722.
- European Association for the Study of the Liver. EASL Clinical Practice Guidelines: Autoimmune hepatitis. J Hepatol. 2015;63(4):971-1004.
- Alvarez F, Berg PA, Bianchi FB, et al. International Autoimmune Hepatitis Group Report: review of criteria for diagnosis of autoimmune hepatitis. J Hepatol. 1999;31(5):929-938.