Cranial and extracranial giant cell arteritis do not have different HLA-DRB1 and HLA-B association in Caucasian individuals

To the editor, We have read with interest the article published in Arthritis Research & Therapy by Kushimoto et al. suggesting that the HLA-B*52 allele may indicate the presence of diffuse extracranial large vessel vasculitis (LVV) in patients with giant cell arteritis (GCA) [1]. Different studies point to the influence of genes located in the MHC region, in particular the HLA-DRB1*04 alleles [7]. Since the pattern of vascular involvement in Takayasu arteritis often resembles that found in patients with extracranial GCA, and the genetic contribution to the pathogenesis of the disease is mainly mediated by the HLA-B*52 allele [8], we wondered if in Caucasian individuals the association of HLA with GCA may differ according to the predominant pattern of the disease. [...]HLA-B*52 cannot be considered as a marker for extracranial LVV in Caucasian individuals over 50 years of age.