The HLA-B*15:02 allele is associated with an increased risk of developing carbamazepine (CBZ)-induced Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).
Along with human leukocyte antigen gene encoding B*51 (HLA-B*51) and areas including the major histocompatibility complex class I, genome-wide association studies have recognized numerous other BD susceptibility genes including those encoding interleukin (IL)-10, IL-12 receptor β 2 (IL-12RB2), IL-23 receptor (IL-23R), C-C chemokine receptor 1 gene, signal transducer and activator of transcription 4 (STAT4), endoplasmic reticulum aminopeptidase (ERAP1), and genes encoding killer cell lectin-like receptor family members (KLRC4-KLRK1).
The distinct effects of both enzymes on the HLA-B*51 peptidome provide a basis for their differential association with Behçet's disease and suggest a pathogenetic role of the B*51:01 peptidome.
To our knowledge, this is the first analysis of KIR3DL1/S1 allelic variation in Behçet disease and may provide insight into the pathogenic role of <i>HLA-B*51</i> and its interaction with KIR3DL1/S1.
In conclusion, two peptides that had high affinity to HLA-B*51:01 in computerized binding prediction showed significantly higher response in HLA-B*51:01-positive patients with BD, indicating the usefulness of computerized simulations for identifying autoreactive peptides to HLAs.
Among the severe cADRs, HLA-B*57:01(OR = 11.00 95% CI: 1.41-85.81) and HLA-DRB1*07:01 (OR = 7.25; 95% CI: 1.09-48.18) were noted to be significantly associated with CBZ-induced Stevens Johnson Syndrome (SJS)/Toxic Epidermal Necrolysis (TEN); HLA-B *51:01 was associated with drug reaction eosinophilia and systemic symptoms (DRESS) caused by PHT (OR = 6.90; 95% CI: 1.38-34.29).
Allergic drug reactions are unpredictable; nevertheless, there is increased risk of drug hypersensitivity in (1) patients with cystic fibrosis who receive antibiotics; (2) patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) who receive trimethoprim-sulfamethoxazole or if human leukocyte antigen (HLA)-B*5701+ and receive the antiretroviral agent abacavir; (3) other genetically susceptible populations, e.g., Han-Chinese with HLA-B*1502+ who develop Stevens-Johnson syndrome and toxic epidermal necrolysis from carbamazepine, with HLA-B*5801+ who are at increased risk for such reactions from allopurinol, those with HLA-A*32:01 and receive vancomycin and develop drug reaction with eosinophilia and systemic symptoms syndrome; and (4) patients with a history of compatible allergic reactions to the same medication, similar class, or potentially unrelated medication.
Our findings suggest that gene-gene interactions between HLA-B*51 and ERAP1 variants is important for BD development, however, ERAP1 variants which interact with HLA-B*51 may differ among disease phenotypes or populations.
Among these variants, the genetic variant associated with Behçet's disease in the <i>HLA-B</i>/<i>MICA</i> region, which tags <i>HLA-B*51</i>, is within novel long intergenic noncoding RNA transcripts that are exclusively expressed from the haplotype with the protective but not the disease risk allele.
HLA-C1<sup>Asn80</sup> showed a protective effect against BD, whereas HLA-C2<sup>Lys80</sup>, HLA-B-Bw4<sup>Ile80</sup>, HLA-B5, and HLA-B51 were associated with a susceptibility risk for BD.
HLA-A*29 and HLA-B*51 are associated with birdshot uveitis and Behçet's disease, respectively, and are used as a diagnostic criterion in patients with suspected disease, requiring their detection in diagnostic laboratories.
However, the low prevalence of HLA-B*51 in many patients with bone fide disease, especially in non-endemic regions, suggests other factors must also be operative in Behçet syndrome.
The variant allele HLA-B*15:02 is strongly associated with greater risk of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in patients treated with carbamazepine or oxcarbazepine.
Due to the significant risk of developing Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), the use of carbamazepine is not recommended in patients carrying the human leukocyte antigen B (HLA-B) *15:02 allele.
Studies found a strong association between allopurinol-induced Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) and the HLA-B*58:01 allele.
The presence of HLA-B*15:02 and CYP2C9 *2 or *3 in the same patient increases the risk of Stevens-Johnson syndrome and toxic epidermal necrolysis; hence, PHT should not be prescribed in these patients.
The alterations in the nature and affinity of HLA-B*51·peptide complexes probably affect T-cell and natural killer cell recognition, providing a sound basis for the joint association of ERAP1 and HLA-B*51 with BD.