HLA associations
HLA antigens are encoded for by genes on chromosome 6. HLA A, B and C are class I antigens whilst DP, DQ, DR are class II antigens. Questions are often based around which diseases have strong HLA associations. The most important associations are listed below:
HLA-A3
HLA-B5
HLA-B27
HLA-DQ2/DQ8
HLA-DR2
HLA-DR3
HLA-DR4
*type 1 diabetes mellitus is associated with HLA-DR3 but is more strongly associated with HLA-DR4.
HLA-A3
- haemochromatosis
HLA-B5
- Behcet's disease
HLA-B27
- ankylosing spondylitis
- Reiter's syndrome
- acute anterior uveitis
HLA-DQ2/DQ8
- coeliac disease
HLA-DR2
- narcolepsy
- Goodpasture's
HLA-DR3
- dermatitis herpetiformis
- Sjogren's syndrome
- primary biliary cirrhosis
HLA-DR4
- type 1 diabetes mellitus*
- rheumatoid arthritis
*type 1 diabetes mellitus is associated with HLA-DR3 but is more strongly associated with HLA-DR4.