HLA‐B*27 subtypes in Northern and Northeastern Thais, Karens, and Bamars determined by a high‐resolution PCR‐SSP technique

Abstract

Human leukocyte antigens (HLA), class I, are a group of antigens expressed on most nucleated cell surfaces. They transport endogenous peptides to the cell surface for recognition by T-cell receptors. Their functions are involved in immune responses. Many diseases are associated with HLA alleles, especially HLA-B*27 that is strongly associated with ankylosing spondylitis (AS). HLA-B*27 consists of 42 subtypes. Different subtypes of HLA-B*27 were reported in different ethnic groups of AS patients. In this study, a high-resolution polymerase chain reaction-sequence-specific primer technique has been developed to define all the HLA-B*27 subtypes with a total of 29 primer mixtures. Two of the primer mixes were used to detect the HLA-B*27-specific group, and 27 primer mixes were used to identify 42 subtypes (B*2701-B*2721 and B*2723-B*2743). The HLA-B*27-group-specific primers have been tested in unrelated healthy subjects; 846 Northeastern Thais (NET), 334 Northern Thais (NT), 264 Karens, and 310 Bamars. Sixty-three NET (phenotype frequency, PF = 7.4%), 24 NT (PF = 7.1%), 5 Karens (PF = 1.8%), and 12 Bamars (PF = 3.9%) were positive for HLA-B*27. Only B*2704 was found in Karens, whereas B*2704, B*2705/37/39, B*2706, and B*2707 were found in NET and NT. In Bamars, B*2704, B*2705/37/39, B*2706, and B*2725 were found. The distribution of HLA-B*27 subtypes was compared with other studies in Asian and Caucasian populations. Significant differences of the distribution of HLA-B*27 subtypes were found in most of the populations. This study established a simple technology for HLA-B*27 subtyping and provided basic information for anthropology and further studies in disease associations.

Does HLA‐B*2706 protect against ankylosing spondylitis? A meta‐analysis

“…After literature search 13 studies were found describing patients or controls with HLA‐B*2706 (Table 1). 4,6–17 All studies reported on Asian individuals and we found no reports of HLA‐B*2706 in non‐Asians. One study was a family study 17 and all the others were population studies.…”

“…In unselected controls 0.45% were HLA‐B*2706‐positive (451 out of 99 420) (range 0.0–5.4). The highest frequency of HLA‐B*2706‐positive controls were reported in studies from Indonesia, 7 Malaysia 4 and Thailand 6,14 …”

Optimization of HLA-B*27 ALLELE Genotyping by PCR-SSP

“…According to Duangchanchot et al (2009), SC1 and SC2 mixes can be used to detect whether the samples are HLA-B*27 -positive or -negative ( 11 ). Our results were in agreement with this, but there was a discordance for SC1 mix, which did not amplify HLA-B*27:12 and HLA-B*27:16 alleles.…”

“…Inexpensive genotyping techniques with high specificity and sensitivity are of great interest in histocompatibility-testing laboratories. Duangchanchot et al (2009) described specific primers for genotyping 42 HLA-B*27 alleles (B*27:01-B*27:21 and B*27:23-B*27:43) using high-resolution polymerase chain reaction with sequence-specific primer (PCR-SSP) ( 11 ). PCR-SSP has been reported to be a simple, fast, inexpensive, specific, and highly sensitive method ( 12 ).…”

Human HLA‐B27 typing using the BD™ HLA‐B27 kit on the BD FACSVia™ system: A multicenter study

“…Although DNA‐based molecular genotyping methods are available to determine the presence of the HLA‐B27 gene , flow cytometric HLA‐B27 screening on peripheral blood lymphocytes using the HLA‐B27 monoclonal antibody is very widely used in clinical diagnostic laboratories due to its simplicity, cost effectiveness, and a short turnaround time . A confounding feature of flow cytometric HLA‐B27 typing is antibody cross‐reactivity caused by the fact that the HLA‐B27 antigen shares common epitopes with a large HLA‐B7 cross‐reacting group (CREG) .…”