To the Editor: Ankylosing spondylitis (AS) is an inflammatory disorder mainly affecting the axial joints, and distinguished by a significant association with HLA-B27. The HLA-B27 gene has a remarkable polymorphism. According to data published in the international ImMunoGeneTics database (IMGT, release 2.24.0), 53 alleles exist, encoding 44 different proteins. The aim of our study was to investigate the distribution of HLA subtype B27 in Han Chinese patients with AS. A registration and followup data bank were established for patients with spondyloarthritis (SpA) who presented at our hospital. The cohort consisted of 408 patients with AS, registered from October 2004 to December 2006. Based on the assignment of random numbers, 100 AS samples were drawn randomly from the data bank. Of these, 2 samples from the same family were treated as duplicates and were excluded. Then, the study consisted of 98 independent individuals, all Han Chinese. Luminex liquid array combined with polymerase chain reaction (PCR)-SSOP (AccuPlex™, Dynal-Invitrogen, USA) was used to obtain low-resolution HLA-B genotype typing. High-resolution HLA-B27 typing of B27-positive individuals was carried out by PCR-SSP (PEL-FREEZ, Dynal-Invitrogen). Sequence-based … Address correspondence to Professor J. Gu, Director of Division of Rheumatology, Department of Medicine, The Third Affiliated Hospital of Sun Yat-sen University, Tianhe Road 600, Guangzhou 510630, People’s Republic of China. E-mail: gujieruo{at}163.com