Rheumatology

The so-called "shared epitope" is the most important genetic risk factor for the development of rheumatoid arthritis. It comprises characteristic peptide sequences at positions 70–74 of the β1 chain of the human leukocyte antigen DR (HLA-DR), which are encoded by various alleles of the HLA-DRB1 gene. The “shared epitope” can be used for genetic risk assessment with respect to the development of rheumatoid arthritis and as a prognostic marker for the expected disease course: The sequences QKRAA, QRRAA, RRRAA and DKRAA are associated with a high risk of developing rheumatoid arthritis and with a severe disease course (high-risk alleles). The peptide sequences DRRAA, QARAA and DERAA, in contrast, are associated with a low disease risk and in some studies have even been described as protective. 

The EUROArray HLA-DRB1 Shared Epitope allows detection and differentiation of all alleles of the relevant shared-epitope peptide sequences in one test. Moreover, through the integrated parallel detection of non-shared epitope alleles, the assay allows differentiation between homozygous and heterozygous carriers. It thus provides improved risk assessment. 

Compared to other molecular biological procedures for the detection of shared-epitope alleles, the EUROArray HLA-DRB1 Shared Epitope is particularly easy to perform and does not require in-depth molecular biology knowledge. Data analysis, data interpretation and electronic archiving are fully automated with the EUROArrayScan software.