[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Immunology](https://durgical.com/en/immunology/) › [Autoimmunity](https://durgical.com/en/immunology/#a-autoimmunity) › HLA associations with disease

[Immunology](https://durgical.com/en/immunology/) · [Autoimmunity](https://durgical.com/en/immunology/#a-autoimmunity)

# HLA associations with disease

- Topic

HLA genes shape which protein pieces immune cells are shown. Some HLA types raise the risk of certain autoimmune diseases or drug reactions.

Updated 2026-11-01

**See it in 3D:** [Sacrum](https://durgical.com/en/anatomy/sacrum/) · [Sacroiliac ligaments](https://durgical.com/en/anatomy/sacroiliac-ligaments/)

## Key points

- B27 = ankylosing spondylitis, reactive and psoriatic arthritis, IBD arthritis, anterior uveitis.
- DQ2/DQ8 = celiac disease (and type 1 diabetes).
- DR3 + DR4 = type 1 diabetes; DR4 = rheumatoid arthritis.
- DR2 (DRB1*15:01) = multiple sclerosis.
- B*57:01 = abacavir hypersensitivity; screen before prescribing.

## What it is

HLA molecules (the human MHC, on chromosome 6) present peptides to T cells, and their variants decide which peptides fit. That is why HLA is the strongest single genetic risk factor for most autoimmune diseases, mostly class II alleles (DR, DQ) with some class I (B27). An HLA association raises risk but does not make the diagnosis: most carriers stay healthy. A few class I alleles also predict severe reactions to specific drugs, and in that setting screening before prescribing is standard.

## Key facts

- Class I (A, B, C) presents to CD8 T cells; class II (DR, DQ, DP) presents to CD4 T cells.
- In celiac disease, tissue transglutaminase modifies gluten peptides so they bind DQ2 and DQ8 more tightly.
- HLA-B27 testing supports, but never alone makes, a diagnosis of spondyloarthritis.
- A Latin American meta-analysis of six autoimmune diseases found shared and disease-specific HLA alleles, part of the idea that autoimmune diseases share roots.

## HLA alleles and the diseases they are linked to

| HLA | Disease | Pearl |
| --- | --- | --- |
| [B27 (class I)](https://durgical.com/en/conditions/ankylosing-spondylitis/) | Ankylosing spondylitis and other spondyloarthritides (reactive, psoriatic, IBD-related arthritis), acute anterior uveitis | Carried by most people with ankylosing spondylitis, yet most carriers never develop it |
| [DQ2 and DQ8 (class II)](https://durgical.com/en/conditions/coeliac-disease/) | Celiac disease | About 90% carry DQ2 and most of the rest DQ8; having neither almost rules celiac disease out |
| [DR3 and DR4 (with DQ2 and DQ8)](https://durgical.com/en/conditions/type-1-diabetes-mellitus/) | Type 1 diabetes | Over 90% of patients carry DR3, DR4 or both; DR3/DR4 heterozygotes have the highest risk |
| [DR4 (DRB1 shared epitope)](https://durgical.com/en/conditions/rheumatoid-arthritis/) | Rheumatoid arthritis | Linked to anti-CCP-positive disease; in Latin Americans mainly DRB1*04:04; smoking adds risk |
| [DR3](https://durgical.com/en/conditions/systemic-lupus-erythematosus/) | Systemic lupus erythematosus, Sjögren syndrome | Linked to anti-Ro and anti-La; DRB1*03:01 is a risk allele for Sjögren in Colombians |
| [DR2 (DRB1*15:01)](https://durgical.com/en/conditions/multiple-sclerosis/) | Multiple sclerosis | Also linked to lupus, but protective against type 1 diabetes |
| B51 | Behçet disease | Oral and genital ulcers, uveitis; most common along the old Silk Road |
| C*06 (Cw6) | Psoriasis | Linked to early-onset psoriasis |
| B*57:01 | Abacavir hypersensitivity | Screen before starting abacavir in HIV treatment |
| B*15:02 | Carbamazepine Stevens–Johnson syndrome/TEN | Mainly in people of Southeast Asian ancestry |

## Memory aid

B27 lives in the spine and the eye; DQ2 lives in the gut; DR3 and DR4 together guard the islet door poorly.

## Test yourself

Think of the answer, then tap the question to see it.

## Which HLA allele is most strongly linked to ankylosing spondylitis?

HLA-B27, a class I allele. Most patients carry it, but most B27 carriers never develop the disease.

## Why is a negative HLA-DQ2/DQ8 test useful in suspected celiac disease?

Almost all patients carry DQ2 or DQ8, so having neither makes celiac disease very unlikely. A positive result, in contrast, is common in healthy people.

## Which HLA test is done before starting abacavir?

HLA-B*57:01. Carriers are at high risk of a severe hypersensitivity reaction, so the drug is avoided in them.

## Which two HLA-DR types together give the highest risk of type 1 diabetes?

DR3 and DR4 (usually with DQ2 and DQ8). Heterozygotes carrying both have the highest risk, especially for onset in early childhood.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/immunology/hla-associations-with-disease/)

## See it in 3D

The structures of Durgical's 3D anatomy where it is found.

- [Sacrum](https://durgical.com/en/anatomy/sacrum/)
- [Sacroiliac ligaments](https://durgical.com/en/anatomy/sacroiliac-ligaments/)

## Related

- [MHC/HLA class I and II](https://durgical.com/en/immunology/mhc-hla-class-i-and-ii/)
- [Immune tolerance and how autoimmunity begins](https://durgical.com/en/immunology/immune-tolerance-and-how-autoimmunity-begins/)
- [Autoantibodies: the table to know](https://durgical.com/en/immunology/autoantibodies-the-table-to-know/)
- [Molecular mimicry and post-infectious autoimmunity](https://durgical.com/en/immunology/molecular-mimicry-and-post-infectious-autoimmunity/)
- [Transplant rejection: hyperacute, acute, chronic](https://durgical.com/en/immunology/transplant-rejection-hyperacute-acute-chronic/)
- [Latex and drug allergy](https://durgical.com/en/immunology/latex-and-drug-allergy/)

## Related conditions

- [Ankylosing spondylitis](https://durgical.com/en/conditions/ankylosing-spondylitis/)
- [Coeliac disease](https://durgical.com/en/conditions/coeliac-disease/)
- [Type 1 diabetes mellitus](https://durgical.com/en/conditions/type-1-diabetes-mellitus/)
- [Rheumatoid arthritis](https://durgical.com/en/conditions/rheumatoid-arthritis/)
- [Systemic lupus erythematosus](https://durgical.com/en/conditions/systemic-lupus-erythematosus/)
- [Multiple sclerosis](https://durgical.com/en/conditions/multiple-sclerosis/)
- [Uveitis](https://durgical.com/en/conditions/uveitis/)
- [Crohn disease](https://durgical.com/en/conditions/crohn-disease/)
- [Ulcerative colitis](https://durgical.com/en/conditions/ulcerative-colitis/)

[← All of immunology](https://durgical.com/en/immunology/)

Educational content on the immune system; not a treatment or individual vaccination guide and no substitute for a health professional's advice. No doses are given.

Sources: [HLA association with autoimmune diseases](https://www.ncbi.nlm.nih.gov/books/n/autoimmuni/hlaassociation/) (El Rosario University Press (NCBI Bookshelf), 2013); [HLA-B27 antigen: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/003551.htm) (MedlinePlus, U.S. National Library of Medicine, 2025); [Autoimmune diabetes mellitus (Type 1A)](https://www.ncbi.nlm.nih.gov/books/n/autoimmuni/autoimmunediabetes/) (El Rosario University Press (NCBI Bookshelf), 2013); [Celiac disease](https://www.ncbi.nlm.nih.gov/books/n/autoimmuni/celiacdisease/) (El Rosario University Press (NCBI Bookshelf), 2013).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/immunology/hla-associations-with-disease/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/immunology/hla-associations-with-disease/