The membrane-bound HLA-B27 protein is associated with the occurrence of several autoimmune diseases, such as ankylosing spondylitis (Bechterew's disease). Around 3 to 6 % of HLA-B*27 carriers develop ankylosing spondylitis. Around 90% of ankylosing spondylitis patients are carriers of this tissue antigen.
The EUROArray HLA-B27 Direct detects all currently known HLA-B*27 subtypes. Furthermore, when a positive result is obtained, it is indicated whether the subtypes HLA-B*27:06 or HLA-B*27:09 could be present. These two subtypes are not associated with ankylosing spondylitis. With the unique direct procedure, the DNA no longer needs to be isolated. The blood sample is treated with two extraction reagents and can then be used directly in the PCR. Data analysis, data interpretation and electronic archiving are fully automated using the EUROArrayScan software. Numerous controls on the EUROArray HLA-B27 verify the correctness of the results. For every reaction it is verified whether human DNA was present in the PCR and whether the primers for the amplification were functional, which is particularly relevant when negative HLA-B27 results are obtained. All of these controls ensure a reliable test result with just one PCR reaction.