Table 2.
The Mattey classification system of the HLA-DRB1 shared epitope in RA.*
| Amino Acid Residue | |||||||
|---|---|---|---|---|---|---|---|
|
|
|||||||
| HLA-DRB1 Alleles | 67 | 70 | 71 | 72 | 73 | 74 | Classification |
| Susceptibility alleles | |||||||
| 0401 | L | Q | K | R | A | A | SE |
| 0101, 0102, 0404, 0405, 0408 | L | Q | K | R | A | A | SE |
| 10 | L | R | R | R | R | A | SE |
| Neutral (D70-) alleles | |||||||
| 03 | L | Q | K | R | G | R | N (D70-) |
| 0403, 0406, 0407 | L | Q | R | R | A | E | N (D70-) |
| 09 | F | R | R | R | A | E | N (D70-) |
| 14 | L | R | R | R | A | E | N (D70-) |
| 15 (1504 is rare) | I | Q | A | R | A | A | N (D70-) |
| Protective (D70+) alleles | |||||||
| 08 (0803 is rare) | F | D | R | R | A | L | P (D70+) |
| 11 | F | D | R | R | A | A | P (D70+) |
| 16 | F | D | R | R | A | A | P (D70+) |
| 0103, 0402 | I | D | E | R | A | A | P (D70+) |
| 07 | I | D | R | R | G | Q | P (D70+) |
| 12 (1202 is rare) | I | D | R | R | A | A | P (D70+) |
| 13 | I | D | E | R | A | A | P (D70+) |
*
In this system described by Mattey et al, shared epitope (SE)-negative alleles are further subdivided according to the amino acid at position 70 (10). Alleles without aspartic acid (D) at position 70 (D70-) are neutral (N), while those with an aspartic acid at position 70 (D70-) appear to confer protection (P).
Letters represent the single-letter abbreviation for amino acids: K - lysine; R - arginine; A - alanine; Q - glutamicacid; G - glycine; D - aspartic acid; L - leucine; I - isoleucine.