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PubMed This is a summary of 14 peer-reviewed journal articles Updated
Hepatology

Making Sense of Your Tests: Labs and Biopsy

At a Glance

Diagnosing autoimmune hepatitis requires a combination of blood tests and a liver biopsy. Doctors use a simplified scoring system that looks at autoantibodies, IgG levels, and specific patterns of liver tissue damage like interface hepatitis to confidently confirm the disease.

Diagnosing Autoimmune Hepatitis (AIH) requires a “weight of evidence” approach. No single test can prove you have it; instead, doctors look at a combination of your blood work, your liver tissue, and the exclusion of other diseases [1][2].

The Simplified Scoring System

To make the diagnosis more consistent, the International Autoimmune Hepatitis Group (IAIHG) created a simplified scoring system. Doctors assign points in four key areas [3][4]:

  1. Autoantibodies: Points are given if you have markers like ANA (Antinuclear Antibody), SMA (Anti-smooth Muscle Antibody), or anti-LKM-1.
  2. IgG Levels: Points are given if your Immunoglobulin G (a type of protein in your immune system) is higher than normal.
  3. Liver Histology (Biopsy): Points are given if your liver tissue shows specific patterns of damage.
  4. Exclusion of Viral Hepatitis: Points are given if tests show you do not have Hepatitis A, B, or C.

What the score means: A score of 6 is considered “probable” AIH, while a score of 7 or higher is considered “definite” AIH [4][5].

Understanding Your Blood Tests

Blood tests for AIH look for two main things: autoantibodies and signs of inflammation.

  • Autoantibodies: These are proteins the immune system uses to target its own body.
    • Type 1 AIH: Usually linked to ANA or SMA [6].
    • Type 2 AIH: Linked to anti-LKM-1 or anti-LC-1 [6].
    • Anti-SLA: This specific antibody can sometimes indicate a more severe disease course that requires long-term monitoring [7].
  • IgG Levels: This is one of the most important markers in AIH. High levels of IgG usually mean the immune system is very active [8]. Doctors use this test not just for diagnosis, but also to see if your treatment is working—bringing your IgG into the normal range is a primary goal of therapy [9][10].

The Liver Biopsy: A Closer Look

A liver biopsy is considered essential because blood tests don’t always show the full picture of liver health [11][12]. A pathologist looks at the tissue under a microscope for these classic signs of AIH:

  • Interface Hepatitis: Inflammation that happens at the edge of the portal tract (the area where blood vessels enter the liver) and spreads into the liver cells [12][13].
  • Plasma Cell Infiltration: A buildup of plasma cells (a type of white blood cell) in the liver, which is a strong signal of an autoimmune response [12].
  • Emperipolesis: A classic, hallmark sign where one white blood cell is seen inside a liver cell [12][14].
  • Rosettes: A pattern where liver cells huddle together in a circular shape due to surrounding damage [12].

Pathology Report Checklist

When you review your pathology report, look for these specific terms to ensure a complete evaluation:

  • Grade (Activity): How much active inflammation is present (often called “necro-inflammatory activity”).
  • Stage (Fibrosis): How much scarring or permanent damage has occurred.
  • Plasma Cells: Whether they were found and in what concentration.
  • Interface Hepatitis: Whether this was observed. You may see the term “piecemeal necrosis”. Note: While the word “necrosis” sounds frightening, in pathology it simply means cellular injury or death on a microscopic level—it does not mean your whole liver is dying.
  • Absence of Other Causes: Confirmation that there are no signs of things like fatty liver or bile duct disease [1].

Common questions in this guide

What is the scoring system for autoimmune hepatitis?
The simplified scoring system helps doctors diagnose AIH by assigning points in four areas: autoantibodies, IgG levels, liver biopsy results, and the absence of viral hepatitis. A score of 6 indicates probable AIH, while 7 or higher confirms definite AIH.
Why is a liver biopsy necessary if my blood tests show autoimmune hepatitis?
A liver biopsy provides essential details about liver health that blood tests alone cannot show. Pathologists examine the tissue under a microscope for specific signs of autoimmune damage, such as interface hepatitis and plasma cell buildup, to confidently confirm the diagnosis.
What does a high IgG level mean for autoimmune hepatitis?
Immunoglobulin G (IgG) is a protein produced by your immune system. High IgG levels typically indicate active liver inflammation. Doctors closely monitor your IgG levels over time because bringing them back into a normal range is a primary goal of treatment.
How do doctors determine if I have Type 1 or Type 2 autoimmune hepatitis?
The type of AIH is determined by the specific autoantibodies found in your blood. Type 1 is typically linked to ANA or SMA antibodies, while Type 2 is associated with anti-LKM-1 or anti-LC-1 antibodies.
What does interface hepatitis mean on my pathology report?
Interface hepatitis is a microscopic finding where inflammation happens at the edge of the portal tract and spreads into the surrounding liver cells. It is considered a classic, hallmark sign of autoimmune hepatitis on a pathology report.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.What was my IAIHG simplified score, and how were the points assigned for my antibodies, IgG, and biopsy?
  2. 2.Does my pathology report mention 'emperipolesis' or 'rosettes,' and how do those findings confirm my diagnosis?
  3. 3.My IgG level is currently [value]—what is our target number for this, and how often will we check it?
  4. 4.Since I tested positive for [Antibody Name], does that mean I have Type 1 or Type 2 AIH, and how does that change my care?

Questions For You

Tap a prompt to share your answer — we'll use it plus this page's context to start a tailored conversation.

References

References (14)
  1. 1

    Autoimmune Hepatitis, Sclerosing Cholangitis, and Autoimmune Sclerosing Cholangitis or Overlap Syndrome.

    Kerkar N, Chan A

    Clinics in liver disease 2018; (22(4)):689-702 doi:10.1016/j.cld.2018.06.005.

    PMID: 30266157
  2. 2

    Letter to the editor: Both simplified and revised IAIHG scores should be considered in diagnosing acute autoimmune hepatitis.

    Shen Y, Xue M, Yang L

    Liver international : official journal of the International Association for the Study of the Liver 2021; (41(8)):1973-1975 doi:10.1111/liv.14946.

    PMID: 33988911
  3. 3

    Autoimmune serology testing in clinical practice: An updated roadmap for the diagnosis of autoimmune hepatitis.

    Dalekos GN, Gatselis NK

    European journal of internal medicine 2023; (108()):9-17 doi:10.1016/j.ejim.2022.11.013.

    PMID: 36400668
  4. 4

    Autoimmune hepatitis: review of histologic features included in the simplified criteria proposed by the international autoimmune hepatitis group and proposal for new histologic criteria.

    Balitzer D, Shafizadeh N, Peters MG, et al.

    Modern pathology : an official journal of the United States and Canadian Academy of Pathology, Inc 2017; (30(5)):773-783 doi:10.1038/modpathol.2016.267.

    PMID: 28106105
  5. 5

    Suitability of the simplified autoimmune hepatitis score for the diagnosis of autoimmune hepatitis in a German cohort.

    Wobser H, Paur T, Schnoy E, et al.

    United European gastroenterology journal 2018; (6(2)):247-254 doi:10.1177/2050640617711632.

    PMID: 29511554
  6. 6

    The importance of autoantibody detection in autoimmune hepatitis.

    Cancado EL, Abrantes-Lemos CP, Terrabuio DR

    Frontiers in immunology 2015; (6()):222 doi:10.3389/fimmu.2015.00222.

    PMID: 26029208
  7. 7

    Prognostic Implications of Antibodies to Soluble Liver Antigen in Autoimmune Hepatitis: A PRISMA-Compliant Meta-Analysis.

    Chen ZX, Shao JG, Shen Y, et al.

    Medicine 2015; (94(23)):e953 doi:10.1097/MD.0000000000000953.

    PMID: 26061326
  8. 8

    Worse fibro-inflammatory activity on diagnostic liver biopsy adversely impacts biochemical remission in autoimmune hepatitis.

    Khonde P, Choudhury S, Spies NC, et al.

    Clinics and research in hepatology and gastroenterology 2024; (48(8)):102442 doi:10.1016/j.clinre.2024.102442.

    PMID: 39103121
  9. 9

    Normalization of serum immunoglobulin G levels is associated with improved transplant-free survival in patients with autoimmune hepatitis.

    Gerussi A, Halliday N, Saffioti F, et al.

    Digestive and liver disease : official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver 2020; (52(7)):761-767 doi:10.1016/j.dld.2020.04.012.

    PMID: 32473882
  10. 10

    Comparison of mycophenolate mofetil with standard treatment for autoimmune hepatitis: a meta-analysis.

    Yu ZJ, Zhang LL, Huang TT, et al.

    European journal of gastroenterology & hepatology 2019; (31(7)):873-877 doi:10.1097/MEG.0000000000001367.

    PMID: 31150366
  11. 11

    The utility of repeat liver biopsy in autoimmune hepatitis: a series of 20 consecutive cases.

    Putra J, Toor A, Suriawinata AA

    Pathology 2016; (48(5)):449-53.

    PMID: 27306577
  12. 12

    Applicability of International Autoimmune Hepatitis Group (IAIHG) Scoring System for Autoimmune Hepatitis in Pediatrics.

    Sakulsaengprapha V, Wasuwanich P, Naraparaju G, et al.

    Biology 2023; (12(3)) doi:10.3390/biology12030479.

    PMID: 36979170
  13. 13

    Statin-induced autoimmune hepatitis in patients with type 1 diabetes: A report of two cases and literature review.

    Kawasaki E, Fukuyama T, Kuriyama E, et al.

    Journal of diabetes investigation 2020; (11(6)):1673-1676 doi:10.1111/jdi.13271.

    PMID: 32277861
  14. 14

    Histological Changes in Autoimmune Hepatitis with Graves' Disease: A Child Case Report.

    Yamada M, Shibata H, Masugi Y, et al.

    Internal medicine (Tokyo, Japan) 2017; (56(16)):2139-2143 doi:10.2169/internalmedicine.8417-16.

    PMID: 28781316

This page explains autoimmune hepatitis test results and pathology terminology for educational purposes. Always discuss your lab work, IgG levels, and liver biopsy reports directly with your hepatologist or gastroenterologist.

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