HLA-B27 subtypes positively and negatively associated with spondyloarthropathy.

OBJECTIVE: Eleven subtypes of HLA-B27 have been identified. If some of these subtypes had a stronger association with spondyloarthropathy (SpA) than others, this might tell us which peptides are of pathogenetic importance. A subtype preponderance has not been proved in Caucasians or in Asian Indians. Our objective was to determine whether some subtypes are positively or negatively associated with SpA in Indonesia. METHODS: Cells of 34 HLA-B27 positive patients with SpA (fulfilling the European Spondylarthropathy Study Group criteria) and 26 HLA-B27 positive controls, all living in Java, Indonesia, were sampled. Patients and controls were divided according to their presumed ethnic origin. HLA-B27 subtyping (B*2701-09) was performed by polymerase chain reaction in combination with sequence specific oligonucleotide probes to analyze polymorphism in exons 2 and 3 of HLA-B27. RESULTS: HLA-B*2701, *2702, *2703, *2708, and *2709 were found in neither group. HLA-B*2704 was found in 23/34 (68%) of the patients and in only 4/26 (15%) of the controls (p < 0.01). HLA-B*2706 was found in none of the 34 patients, but in 21/26 (81%) of the controls (p < 0.01). One drawback of the study was that most patients were of Chinese descent and most controls were native Javanese. Nevertheless, the absence of SpA among HLA-B*2706 positive individuals is noteworthy. CONCLUSION: HLA-B*2704 is positively associated with SpA (RR = 11.5), while *2706 is negatively associated with this disease (RR < 0.007). The results confirm the findings of Lopez-Larrea, et al in Thailand.

Higher relative risk of spondyloarthropathies among B27 positive Indonesian Chinese than native Indonesians.

We assessed the prevalence of HLA-B27 among ethnic Indonesian and Indonesian Chinese patients with ankylosing spondylitis (AS) or related spondyloarthropathies, and also among healthy controls. HLA-B27 was found in 23 (62.2%) of 37 Chinese patients and 4% of 176 Chinese healthy controls (p < 0.001). In contrasts only 2 (8.3%) of 24 native Indonesian patients and 13 (9%) of 145 healthy controls were HLA-B27+, indicating the lack of association of HLA-B27 with spondyloarthropathies in native Indonesians. These findings also suggest that HLA-B27 Chinese Indonesians carry a greater relative risk of developing AS and related spondyloarthropathies than native Indonesians, although the prevalence of HLA-B27 in the general population is more than 2 times higher in native Indonesians.