HLA-B27 subtypes in Asian patients with ankylosing spondylitis. Evidence for new associations

Tissue Antigens. 1995 Mar;45(3):169-76. doi: 10.1111/j.1399-0039.1995.tb02436.x.


The aim of this study was to investigate the contribution of the different B27 subtypes to ankylosing spondylitis (AS) susceptibility. The polymerase chain reaction (PCR) in combination with the sequence-specific oligonucleotide probes (SSOs) was used to analyse the polymorphism in exon 2 and 3 of HLA-B27 in two Asian groups with different genetic HLA structures: Indian (I) and Thai (T) populations. The same number of AS patients (45) and healthy B27 positive donors (n = 17) from both populations were analysed in order to ascertain the B27 subtypes. Three different findings can be concluded from this study: 1) B*2707 has been found to be associated with AS in both populations. This association has not been previously reported in either ethnic group. 2) B*2704 is strongly associated with AS in the Thai patients (91% in AS vs. 47% in C; RR = 11.5; EF = 0.83). In contrast, B*2704 was found with similar frequency in Asian Indians AS patients and controls (41% in AS vs. 41% in C.). 3) B*2706 was found overrepresented in control populations and absent in AS patients (0% in AS vs. 47% in C.; pc < 10(-6)) showing the maximum value of protective fraction (PF = 1). The B*2706 negative association with AS has not been previously described in other ethnic groups and could indicate a protective effect of this subtype on AS susceptibility. The B*2706 allele has two changes relative to B*2704 at residue 114 (His to Asp) and 116 (Asp to Tyr) in the pockets D/E. The importance that these differences can play in the pathogenesis of AS are discussed.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Case-Control Studies
  • DNA / blood
  • DNA Probes, HLA
  • Gene Frequency
  • Genes, MHC Class I / genetics*
  • HLA-B27 Antigen / classification
  • HLA-B27 Antigen / genetics*
  • Humans
  • India
  • Molecular Sequence Data
  • Point Mutation
  • Polymerase Chain Reaction
  • Protein Conformation
  • Spondylitis, Ankylosing / ethnology
  • Spondylitis, Ankylosing / genetics*
  • Thailand


  • DNA Probes, HLA
  • HLA-B27 Antigen
  • DNA