Table 2.
HLA genetics and risk associated with CD.
| HLA-DQA1 alleles | HLA-DQB1 alleles | HLA-DQ heterodimers | Predisposition for CD+ |
|---|---|---|---|
| *05:01, *05:01 | *02:01, *02:01 | DQ2.5 (homozygous) | Very high |
| *05:01, *03 | *02:01, *03:02 | DQ2.5/DQ8/DQ2.3/DQ8.5 | Very high |
| *05:01, *02:01 | *02:01, *02:02 | DQ2.5/DQ2.2 (encoded in cis and trans) | Very high |
| *05:01, x | *02:01, *02 | DQ2.5 (encoded in cis and trans) | Very high |
| *05:01, x | *02:01, x | DQ2.5 (heterozygous) | High |
| *05:05, *02:01 | *03:01, *02:02 | DQ2.5 (encoded in trans)/DQ2.2 | High |
| *03, *03 | *03:02, *03:02 | DQ8 (homozygous) | High |
| *03, *02:01 | *03:02, *02:02 | DQ8/DQ2.2/DQ2.3 | High |
| *03, x | *03:02, *02 | DQ8/DQ2.3 | High |
| *03, x | *03:02, x | DQ8 (heterozygous) | Intermediate |
| *02:01, *02:01 | *02:02, *02:02 | DQ2.2 (homozygous) | Intermediate |
| *02:01, x | *02:02, *02 | DQ2.2 (encoded in cis and trans) | Intermediate |
| x, x | *02:01, *02:01 | Half DQ2.5 | Intermediate |
| *02:01, x | *02:02, x | DQ2.2 (heterozygous) | Low |
| x, x | *02:01 | Half DQ2.5 | Low |
| *05:01 | x, x | Half DQ2.5 | Low |
| *03:01, x | *02:01, x | DQ2.3/x | ND++, # |
| *05, x | *03:02, x | DQ8.5/x | ND |
| *03, x | *03:03, x | DQ9/x | ND |
+Predisposition for CD is based on the prevalence of genes/haplotypes and the immune recognition of CD-associated gluten T-cell epitopes [28–38].
++ND; nondetermined.
#It is possible that some HLA-DQ2.5 “restricted” gluten T-cell epitopes can be loaded and presented by the heterodimer DQ2.3 [31].
x denotes a non-CD related genotype.