Published online Jan 21, 2022. doi: 10.12998/wjcc.v10.i3.992
Peer-review started: February 26, 2021
First decision: October 16, 2021
Revised: October 27, 2021
Accepted: December 25, 2021
Article in press: December 25, 2021
Published online: January 21, 2022
Processing time: 323 Days and 1.8 Hours
Ankylosing spondylitis (AS) is strongly associated with the human leukocyte antigen (HLA) B27 haplotype. In regions where conventional polymerase chain reaction for HLA typing is available for antigens such as HLA B27 or HLA B51, it is common to perform the HLA B27 test for evaluation of AS. While HLA B27-associated clustered occurrences of AS have been reported in families, we report the first case series of HLA B51-related occurrences of AS in a family.
A father and his daughters were diagnosed with AS and did not have the HLA B27 haplotype. Although they were positive for HLA B51, they exhibited no signs of Behçet’s disease (BD). Of the five daughters, one had AS, and three, including the daughter with AS, were positive for HLA B51. The two daughters with the HLA B51 haplotype (excluding the daughter with AS) exhibited bilateral grade 1 sacroiliitis, whereas the daughters without the HLA B51 haplotype did not have sacroiliitis. Thus, this Korean family exhibited a strong association with the HLA B51 haplotype and clinical sacroiliitis, irrespective of the symptoms of BD.
It is advisable to check for HLA B51 positivity in patients with AS/spondyloarthropathy who test negative for HLA B27.
Core Tip: Ankylosing spondylitis (AS) is strongly associated with human leukocyte antigen (HLA) B27. In certain regions, the testing of HLA genotyping, such as HLA B27 or HLA B51, is an available medical service. Here, we report the first case series of HLA B51-related inheritance of AS in a family. No one in this family tested positive for HLA B27, and additional testing for HLA B51 revealed that family members with HLA B51 haplotype had either AS or clinical sacroiliitis without symptoms compatible with Behçet’s disease. Thus, it is advisable to perform HLA B51 testing as a genetic marker for HLA B27 negative AS/spondyloarthropathy.