Role of HLA-DR in the pathogenesis of abdominal aortic aneurysm

to establish a possible role for autoimmunity in the aetiology of abdominal aortic aneurysm (AAA) by examining human leukocyte antigen class II (HLA-II) immune response genes.

HLA-II typing was performed in a series of 72 AAA patients and a control group of 380 healthy subjects.

a higher incidence of the allele subtype HLA-DR B1*0401 was detected in the AAA group with respect to the control group (12.5 vs 5.2%; p = 0.02, OR 2.59). In contrast, the HLA-DR B1*01 allele tended to behave as a protective factor for AAA (12.5% AAA vs 21.3% controls; p = 0.09, OR 0.5).

the association observed here between HLA-DR B1*0401 and HLA-DR B1*01 and unspecific AAA is similar to that reported in several autoimmune diseases. This similarity suggests an essential role for autoimmune factors in the formation of the AAA.