The genes that encode HLA (Human Leukocyte Antigen) are on chromosome 6.
| MHC class | Type | Location | Function |
| I | HLA-A, -B, -C | All cells | Recognized by CD8+ lymphocytes |
| II | HLA-DP, -DQ, -DR | Antigen presenting cells | Recognized by CD4+ lymphocytes |
| III | Complement components | Plasma | Chemotaxis, opsonization, lysis of bacteria and cells |
The rhymes
Two and Three – SLE
Three and Four – Sugar
HLA DR-2 and DR-3: SLE
- HLA DR-2: Japanese SLE
- HLA DR-3: Caucasian SLE
HLA DR-3 and DR-4: Diabetes Mellitus type 1 (IDDM)
Bet (B8) – Death (Grave)
HLA B-8:
- GRAVE’s disease
- Myasthenia GRAVIS
HLA DR-3 and B-8 share same disease associations many times:
- Graves’ disease
- Myasthenia gravis
- Sarcoidosis
- Sjogren’s syndrome
- Celiac disease and Dermatitis herpetiformis
- SLE
- Dermatomyositis
- Addison’s disease
C 6 – Sis Vulgaris
- HLA CW-6: Psoriasis vulgaris
Seven – Pee in Heaven
HLA-DR7: Steroid responsive nephrotic syndrome
Other Mnemonics
Two pairs of alphabets – GH and MN
HLA DR-2:
- Goodpasture’s syndrome
- Hayfever
- Multiple Sclerosis (MS)
- Narcolepsy
Take 1st letter from DM and 1st letter from RA, and in total they make 4 letters
DM + RA = DR4
HLA-DR4:
- Diabetes Mellitus
- Rheumatoid Arthritis (93% have HLA type)
If you see B with 5 it’s Behcet’s disease
- HLA B-5
- HLA B-51
- HLA B-52
HLA DR-5:
- Pernicious anemia
- Juvenile idiopathic arthritis
- Hashimoto’s thyroiditis
- Alopecia areata
HLA A-3: Ferric ion is trivalent
- Hemochromatosis
HLA B-27: PAIR
Seronegative arthritis:
- Psoriatic arthritis
- Ankylosing spondylitis (relative risk 70-90%)
- Inflammatory bowel disease
- Reiter’s syndrome (relative risk 40%)