> For the complete documentation index, see [llms.txt](https://www.parapathology.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://www.parapathology.com/clippings/a-deep-learning-based-model-for-assessment-of-autoimmune-hepatitis-from-histology-ai-h.md).

# A deep-learning-based model for assessment of autoimmune hepatitis from histology: AI(H)

Histological assessment of autoimmune hepatitis (AIH) is challenging. As one of the possible results of these challenges, nonclassical features such as bile-duct injury stays understudied in AIH. We a

### Summary

Autoimmune hepatitis (AIH) has no pathognomonic lesion. Its biopsies show the elementary lesions of any chronic hepatitis, graded semi-quantitatively with poor inter-observer agreement, and non-classical features such as bile duct injury are understudied.

**AI(H)** is a stack of convolutional networks trained on the Aiforia platform. Each model targets one part of AIH histology:

* on H\&E: tissue, liver microanatomy, necroinflammation, portal inflammation, immune-cell types and bile duct damage;
* on Sirius red: fibrosis.

The models were trained on pre-treatment biopsies from University Hospital Basel. Against pathologist annotations, test accuracy ranged from 72% (immune-cell classification) to 99% (tissue detection). The tool found bile duct injury in about two-thirds of AIH biopsies.

> The abstract in the `description:` frontmatter is the paper's own, verbatim. The sections below are my own-words digest of the abstract and the open-access full text in PubMed Central.

### Citation

Ercan C, Kordy K, Knuuttila A, Zhou X, Kumar D, Koponen V, et al. A deep-learning-based model for assessment of autoimmune hepatitis from histology: AI(H). *Virchows Arch*. 2024;485(6):1095–1105. Epub 2024 Jun 15. doi: [10.1007/s00428-024-03841-5](https://doi.org/10.1007/s00428-024-03841-5). PMID: [38879691](https://pubmed.ncbi.nlm.nih.gov/38879691/). PMCID: [PMC11666607](https://pmc.ncbi.nlm.nih.gov/articles/PMC11666607/).

* **Platform:** Aiforia (cloud-based, supervised deep learning)
* **Access:** open access, full text in PubMed Central

### Study at a glance

| Item             | Detail                                                                                                                               |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------ |
| Cohort           | 116 adult AIH patients (94 women, 22 men; mean age 59), Basel archive 1996–2020; 123 paired H\&E and Sirius red pre-treatment slides |
| Split            | Random 80/20: 99 training slides, 24 test slides                                                                                     |
| Annotations      | Immune cells by two pathologists (7,868 immune-cell annotations in total); all other classes by one pathologist                      |
| Clinical grading | Ishak grading and staging by two pathologists in consensus, plus International AIH Pathology Group criteria                          |
| Scanner          | 3DHISTECH Pannoramic SCAN II, 40× (0.24 µm/px)                                                                                       |

### Key findings

| Model                                                                      | Stain             | Test accuracy                          |
| -------------------------------------------------------------------------- | ----------------- | -------------------------------------- |
| Tissue detection                                                           | H\&E / Sirius red | 99.4% / 99.4%                          |
| Liver microanatomy (portal, parenchyma, central vein)                      | H\&E / Sirius red | 88.0% / 94.0%                          |
| Necroinflammation (interface hepatitis, focal and confluent necrosis)      | H\&E              | 83.9%                                  |
| Bile duct damage                                                           | H\&E              | 81.7%                                  |
| Portal inflammation (mild / moderate / severe)                             | H\&E              | 79.2%                                  |
| Immune cells (lymphocyte, plasma cell, macrophage, eosinophil, neutrophil) | H\&E              | 72.4%                                  |
| Fibrosis                                                                   | Sirius red        | 87.6% (88.0% in the full-text Results) |

* **Bile duct injury** appeared in 68.6% of biopsies (81 cases). That is closer to one earlier report (72%) than to others (24%, 83%).
* **Tracking the pathologists.** AI(H) counts of focal necrosis, the extent of interface hepatitis and the moderate portal-inflammation ratio all rose in step with the pathologists' Ishak scores, and so did the densities of all five immune-cell types.
* **Toward the consensus criteria.** Fed into the International AIH Pathology Group criteria, AI(H) outputs sorted biopsies into "likely" and "possible" AIH with 88.2% agreement with the pathologist. Most errors came from overcalling interface hepatitis and from faded archival slides.
* **Other hepatitides.** Exploratory runs on a handful of drug-induced, HBV and HCV biopsies recognised the same elementary lesions, with some errors.

### Limitations noted by the authors

* Single institution, with most annotations by one pathologist. Consensus grading meant inter-observer variability could not be measured.
* Accuracy fell in heavily necroinflamed or architecturally disrupted biopsies, and immune-cell detection struggled in dense infiltrates.
* The tool is image-only: no clinical or laboratory data, and other liver diseases were excluded, so it is not a diagnostic tool.
* Fibrosis used Sirius red only. There was no elastic stain to separate recent collapse from established fibrosis.

### On the lecture slide

From a lecture slide titled *"Top quantitative models in GI/liver path"*:

| Disease              | Model         | Output                        | Training set | Reference                        |
| -------------------- | ------------- | ----------------------------- | ------------ | -------------------------------- |
| Autoimmune hepatitis | AI(H) (Ercan) | Immune-cell density, necrosis | 99 WSIs      | Ercan et al. Virchows Arch. 2024 |

"99 WSIs" **matches** the training split (99 training, 24 test, of 123 slides).
