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Fulltext The spectrum of association in HLA region with rheumatoid arthritis in a diverse Asian population: evidence from the MyEIRA case-control study

Tan LK, Too CL, Diaz-Gallo LM, Wahinuddin S, Lau IS, Heselynn H, et al.

Arthritis Res Ther, 2021 01 30;23(1):46.
PMID: 33514426 DOI: 10.1186/s13075-021-02431-z

BACKGROUND: Fine-mapping of human leukocyte antigen (HLA) region for rheumatoid arthritis (RA) risk factors has identified several HLA alleles and its corresponding amino acid residues as independent signals (i.e., HLA-A, HLA-B, HLA-DPB1, and HLA-DQA1 genes), in addition to the well-established genetic factor in HLA-DRB1 gene. However, this was mainly performed in the Caucasian and East Asian populations, and data from different Asian regions is less represented. We aimed to evaluate whether there are independent RA risk variants in both anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA patients from the multi-ethnic Malaysian population, using the fine-mapping of HLA region strategy.
METHODS: We imputed the classical HLA alleles, amino acids, and haplotypes using the Immunochip genotyping data of 1260 RA cases (i.e., 530 Malays, 259 Chinese, 412 Indians, and 59 mixed ethnicities) and 1571 controls (i.e., 981 Malays, 205 Chinese, 297 Indians, and 87 mixed ethnicities) from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis (MyEIRA) population-based case-control study. Stepwise logistic regression was performed to identify the independent genetic risk factors for RA within the HLA region.
RESULTS: We confirmed that the HLA-DRB1 amino acid at position 11 with valine residue conferred the strongest risk effect for ACPA-positive RA (OR = 4.26, 95% CI = 3.30-5.49, PGWAS = 7.22 × 10-29) in the Malays. Our study also revealed that HLA-DRB1 amino acid at position 96 with histidine residue was negatively associated with the risk of developing ACPA-positive RA in the Indians (OR = 0.48, 95% CI = 0.37-0.62, PGWAS = 2.58 × 10-08). Interestingly, we observed that HLA-DQB1*03:02 allele was inversely related to the risk of developing ACPA-positive RA in the Malays (OR = 0.17, 95% CI = 0.09-0.30, PGWAS = 1.60 × 10-09). No association was observed between the HLA variants and risk of developing ACPA-negative RA in any of the three major ethnic groups in Malaysia.
CONCLUSIONS: Our results demonstrate that the RA-associated genetic factors in the multi-ethnic Malaysian population are similar to those in the Caucasian population, despite significant differences in the genetic architecture of HLA region across populations. A novel and distinct independent association between the HLA-DQB1*03:02 allele and ACPA-positive RA was observed in the Malays. In common with the Caucasian population, there is little risk from HLA region for ACPA-negative RA.

Matched MeSH terms: HLA-DRB1 Chains/genetics
Fulltext Smoking interacts with HLA-DRB1 shared epitope in the development of anti-citrullinated protein antibody-positive rheumatoid arthritis: results from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis (MyEIRA)

Too CL, Yahya A, Murad S, Dhaliwal JS, Larsson PT, Muhamad NA, et al.

Arthritis Res Ther, 2012;14(2):R89.
PMID: 22537824 DOI: 10.1186/ar3813

INTRODUCTION:Rheumatoid arthritis (RA) is a multifactorial autoimmune disease in which genetic and environmental factors interact in the etiology. In this study, we investigated whether smoking and HLA-DRB1 shared-epitope (SE) alleles interact differently in the development of the two major subgroups of rheumatoid arthritis (RA), anti-citrullinated proteins antibody (ACPA)-positive and ACPA-negative disease, in a multiethnic population of Asian descent.
METHODS: A case-control study comprising early diagnosed RA cases was carried out in Malaysia between 2005 and 2009. In total, 1,076 cases and 1,612 matched controls participated in the study. High-resolution HLA-DRB1 genotyping was performed for shared-epitope (SE) alleles. All participants answered a questionnaire on a broad range of issues, including smoking habits. The odds ratio (OR) of developing ACPA-positive and ACPA-negative disease was calculated for smoking and the presence of any SE alleles separately. Potential interaction between smoking history (defined as "ever" and "never" smoking) and HLA-DRB1 SE alleles also was calculated.
RESULTS: In our multiethnic study, both the SE alleles and smoking were associated with an increased risk of developing ACPA-positive RA (OR SE alleles, 4.7; 95% confidence interval (CI), 3.6 to 6.2; OR smoking, 4.1; 95% CI, 1.9 to 9.2). SE-positive smokers had an odds ratio of ACPA-positive RA of 25.6 (95% CI, 10.4 to 63.4), compared with SE-negative never-smokers. The interaction between smoking and SE alleles was significant (attributable proportion due to interaction (AP) was 0.7 (95% CI, 0.5 to 1.0)). The HLA-DRB1*04:05 SE allele, which is common in Asian populations, but not among Caucasians, was associated with an increased risk of ACPA-positive RA, and this allele also showed signs of interaction with smoking (AP, 0.4; 95% CI, -0.1 to 0.9). Neither smoking nor SE alleles nor their combination was associated with an increased risk of ACPA-negative RA.
CONCLUSIONS: The risk of developing ACPA-positive RA is associated with a strong gene-environment interaction between smoking and HLA-DRB1 SE alleles in a Malaysian multiethnic population of Asian descent. This interaction seems to apply also between smoking and the specific HLA-DRB1*04:05 SE allele, which is common in Asian populations but not in Caucasians.

Matched MeSH terms: HLA-DRB1 Chains/genetics; HLA-DRB1 Chains/immunology; HLA-DRB1 Chains/metabolism*
Distribution of HLA-A, -B and -DRB1 alleles in the Kensiu and Semai Orang Asli sub-groups in Peninsular Malaysia

Tasnim AR, Allia S, Edinur HA, Panneerchelvam S, Zafarina Z, Norazmi MN

Hum Immunol, 2016 Aug;77(8):618-619.
PMID: 27296326 DOI: 10.1016/j.humimm.2016.06.009

The earliest settlers in Peninsular Malaysia are the Orang Asli population, namely Semang, Senoi and Proto Malays. In the present study, we typed the HLA-A, -B and -DRB1 loci of the Kensiu and Semai Orang Asli sub-groups. Sequence-based HLA typing was performed on 59 individuals from two Orang Asli sub-groups. A total of 11, 18 and 14 HLA-A, -B and -DRB1 alleles were identified, respectively. These data are available in the Allele Frequencies Net Database under the population name "Malaysia Kedah Kensiu" and "Malaysia Pahang Semai".

Matched MeSH terms: HLA-DRB1 Chains/genetics*
Fulltext Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results from a Malaysian population-based case-control study

Too CL, Muhamad NA, Ilar A, Padyukov L, Alfredsson L, Klareskog L, et al.

Ann Rheum Dis, 2016 06;75(6):997-1002.
PMID: 26681695 DOI: 10.1136/annrheumdis-2015-208278

OBJECTIVES: Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke.

METHODS: Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case-control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR β-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI.

RESULTS: Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2).

CONCLUSIONS: This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene-environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

Matched MeSH terms: HLA-DRB1 Chains/genetics; HLA-DRB1 Chains/immunology
Susceptibility to aplastic anemia is associated with HLA-DRB1*1501 in an aboriginal population in Sabah, Malaysia

Dhaliwal JS, Wong L, Kamaluddin MA, Yin LY, Murad S

Hum Immunol, 2011 Oct;72(10):889-92.
PMID: 21762745 DOI: 10.1016/j.humimm.2011.06.013

The incidence of aplastic anemia is reported to be higher in Asia than elsewhere. We studied the frequency of human leukocyte antigen (HLA) DRB1 alleles in aplastic anemia patients from 2 genetically similar aboriginal groups, the Kadazan and the Dusun, and compared them with genetically matched community and hospital controls. HLA-DRB1*15 was significantly higher in the patients compared with controls (p = 0.005), confirming similar findings in Japanese and Caucasian studies. Further testing indicated a significantly higher frequency of HLA-DRB1*1501 in patients compared with controls (p = 0.0004) but no significant difference in the frequency of HLA-DRB1*1502. The high frequency of HLA-DRB1*15 in the Kadazan and Dusun population combined with the wide variety of environmental factors associated with aplastic anemia could be the reason for the elevated incidence of aplastic anemia in the Kadazan and Dusun in Sabah.

Matched MeSH terms: HLA-DRB1 Chains/analysis*; HLA-DRB1 Chains/genetics; HLA-DRB1 Chains/immunology
Fulltext The HLA DPB1*02:01:02 and DQB1*05:02:01 alleles as possible risk factors for colorectal carcinoma in the Malaysian population

Sri Noraima Othman, Nor Adzimah Johdi, Zuraini Abd Razak, Luqman Mazlan, Ismail Sagap, Rahman Jamal

Asia-Pacific Journal of Molecular Medicine, 2016;6(2):1-8.
MyJurnal

Many studies have shown that the immune response highly depends on the inheritance of specific HLA
genes in promoting the generation of T cells for the elimination of pathogens. Loss or alteration of HLA
antigen expression in tumor cells has been observed in a variety of human malignancies leading to immune
escape or immune resistance. We investigated whether the inheritance of certain alleles of HLA class II
genes confers susceptibility or resistance towards the development of colorectal carcinoma (CRC).
Molecular typing of HLA DRB1, DQB1 and DPB1 alleles in 42 patients diagnosed with CRC and 50
ethnically matched healthy controls using the PCR-sequence based typing (PCR-SBT) was conducted. The
HLA DPB1*02:01:02 was significantly higher in CRC patients (38.1%, p=0.0189) compared to healthy
controls (16%). Also, HLA DQB1*05:02:01 was present in 28.6% of CRC patients but only 10% of healthy
controls (p=0.0278). The odds ratios for HLA DPB1*02:01:02 and HLA DQB1*05:02:01were 3.23 and 3.60,
respectively. There were no significant association observed for the DRB1 allele with CRC. Our study
suggests that the HLA DPB1*02:01:02 and HLA DQB1*05:02:01 alleles may confer a higher risk for CRC

Matched MeSH terms: HLA-DRB1 Chains
Fulltext Association between alleles, haplotypes, and amino acid variations in HLA class II genes and type 1 diabetes in Kuwaiti children

Dashti M, Nizam R, Jacob S, Al-Kandari H, Al Ozairi E, Thanaraj TA, et al.

Front Immunol, 2023;14:1238269.
PMID: 37638053 DOI: 10.3389/fimmu.2023.1238269

Type 1 diabetes (T1D) is a complex autoimmune disorder that is highly prevalent globally. The interactions between genetic and environmental factors may trigger T1D in susceptible individuals. HLA genes play a significant role in T1D pathogenesis, and specific haplotypes are associated with an increased risk of developing the disease. Identifying risk haplotypes can greatly improve the genetic scoring for early diagnosis of T1D in difficult to rank subgroups. This study employed next-generation sequencing to evaluate the association between HLA class II alleles, haplotypes, and amino acids and T1D, by recruiting 95 children with T1D and 150 controls in the Kuwaiti population. Significant associations were identified for alleles at the HLA-DRB1, HLA-DQA1, and HLA-DQB1 loci, including DRB1*03:01:01, DQA1*05:01:01, and DQB1*02:01:01, which conferred high risk, and DRB1*11:04:01, DQA1*05:05:01, and DQB1*03:01:01, which were protective. The DRB1*03:01:01~DQA1*05:01:01~DQB1*02:01:01 haplotype was most strongly associated with the risk of developing T1D, while DRB1*11:04-DQA1*05:05-DQB1*03:01 was the only haplotype that rendered protection against T1D. We also identified 66 amino acid positions across the HLA-DRB1, HLA-DQA1, and HLA-DQB1 genes that were significantly associated with T1D, including novel associations. These results validate and extend our knowledge on the associations between HLA genes and T1D in Kuwaiti children. The identified risk alleles, haplotypes, and amino acid variations may influence disease development through effects on HLA structure and function and may allow early intervention via population-based screening efforts.

Matched MeSH terms: HLA-DRB1 Chains
HLA variants rs9271366 and rs9275328 are associated with systemic lupus erythematosus susceptibility in Malays and Chinese

Chai HC, Phipps ME, Othman I, Tan LP, Chua KH

Lupus, 2013 Feb;22(2):198-204.
PMID: 23257407 DOI: 10.1177/0961203312470183

BACKGROUND: Human leukocyte antigen (HLA) antigens and genes have long been reported associated with systemic lupus erythematosus (SLE) susceptibility in many populations. With the advance in technologies such as genome-wide association studies, many newly discovered SLE-associated single-nucleotide polymorphisms (SNPs) have been reported in recent years. These include HLA-DRB1/HLA-DQA1 rs9271366 and HLA-DQB1/HLA-DQA2 rs9275328. Our aim was to investigate these SNPs in a Malaysian SLE cohort.
MATERIALS AND METHODS: SNPs rs9271366 and rs9275328 were screened across 790 Malaysian citizens from three ethnic groups (360 patients and 430 healthy volunteers) by Taqman SNP genotyping assays. Allele and genotyping frequencies, Hardy-Weinberg equilibrium, Fisher's exact test and odds ratio were calculated for each SNP and ethnic group. Linkage disequilibrium and interaction between the two SNPs were also evaluated.
RESULTS: The minor allele G and its homozygous genotype GG of HLA-DRB1/HLA-DQA1 rs9271366 significantly increased the SLE susceptibility in Malaysian patients, including those of Malay and Chinese ethnicity (odds ratio (OR) > 1, p HLA-DQB1/HLA-DQA2 rs9275328, the minor allele T and the heterozygous genotype CT conferred protective effect to SLE in Malaysians, as well as in Malays and Chinese, by having OR HLA variants, rs9271366 and rs9275328 are additional polymorphisms worth considering in the Malaysian and possibly in a larger Asian SLE scenario.

Matched MeSH terms: HLA-DRB1 Chains/genetics*
Fulltext Increased soluble HLA-DRB1in B-cell acute lymphoblastic leukaemia

Hassan N, Dhaliwal JS, Mohd Ibrahim H, Osman R, HIdris SZ, Lee le J, et al.

Malays J Pathol, 2015 Aug;37(2):83-90.
PMID: 26277663 MyJurnal

Soluble HLA (sHLA) are potential tumour markers released in order to counter immune surveillance. sHLA-class II is less known especially in acute lymphoblastic leukaemia (ALL). This study aimed to investigate soluble, surface and allelic expression of HLA Class II (sHLA-DR) in B-cell ALL patients and compare with soluble expression in normal individuals. A sandwich enzyme-linked immunosorbent assay (ELISA) was developed to measure soluble HLA-DRB1 in plasma. Flow cytometric analysis was performed to determine median fluorescence intensity in HLA-DR surface expression. HLA-DNA typing by polymerase chain reaction, sequence specific oligonucleotides, PCRSSO was performed to determine HLA-DRB1 type in ALL samples. Results showed sHLA-DRB1 (mean±SEM) was significantly increased (p=0.001) in plasma of ALL patients (0.260 ±0.057 μg/mL; n=30) compared to healthy controls (0.051 ± 0.007µg/mL; n=31) of Malay ethnicity. However, these levels did not correlate with percentage or median fluorescence intensity of HLA-DR expressed on leukemia blasts (CD19+CD34 ± CD45(lo)HLA-DR+) or in the normal B cell population (CD19+CD34- CD45(hi)HLA-DR+) of patients. No significant difference was observed in gender (male/female) or age (paediatric/adult). Only a trend in reduced sHLA was observed in patients carrying HLA-DR04. These results have to be validated with a larger number of samples.

Matched MeSH terms: HLA-DRB1 Chains/biosynthesis*
Fulltext Recognizing rheumatoid arthritis: oncoprotein survivin opens new possibilities: a population-based case-control study

Chun-Lai T, Murad S, Erlandsson MC, Hussein H, Sulaiman W, Dhaliwal JS, et al.

Medicine (Baltimore), 2015 Jan;94(4):e468.
PMID: 25634192 DOI: 10.1097/MD.0000000000000468

Survivin is a biomarker of cancer known for its anti-apoptotic and cell-cycle regulating properties. In the context of non-cancer pathology, high levels of survivin may be measured in blood and synovial fluid of patients with rheumatoid arthritis (RA) and associate with early joint damage and poor therapy response. The aim of the study was to investigate the value of survivin measurements in blood for diagnosis of RA in the frame of the Malaysian epidemiological investigation of rheumatoid arthritis (MyEIRA) study. The study enrolled RA patients from eight rheumatology centres in Peninsular Malaysia. The healthy controls matched by age, gender and ethnicity were recruited on the community basis from the residential area of the patients. Levels of survivin were measured in blood of RA patients (n = 1233) and controls (n = 1566) by an enzyme-linked immuno-sorbent assay (ELISA). The risk for RA was calculated as odds ratio (OR) and 95% confidence intervals in the individuals with high levels of survivin. The risk was calculated in relation to antibodies against cyclic citrullinated peptides (ACPA), detected by ELISA and HLA-DRB1 shared epitope (SE) alleles, identified by the polymerase chain reaction using sequence specific oligonucleotide method. High levels of survivin were detected in 625 of 1233 (50.7%) RA cases and in 85 of 1566 (5.4%) controls, indicating its high specificity for RA. Survivin was association with an increase in RA risk in the patients having neither SE-alleles nor ACPA (OR = 5.40, 95% CI 3.81-7.66). For the patients combining survivin, SE, and ACPA, the estimated risk for RA was 16-folds higher compared to the survivin negative patients with SE and ACPA(OR = 16.21, 95% CI 5.70-46.18). To conclude, detection of survivin in blood provides a simple test to improve diagnostic and to increase predictability for RA.

Matched MeSH terms: HLA-DRB1 Chains/genetics
HLA-A, -B, -C, -DRB1 and -DQB1 alleles and haplotypes in 194 Southeast Asia Chinese from Peninsular Malaysia

Too CL, Tan LK, Heselynn H, Nor-Shuhaila S, Eashwary M, Wahinuddin S, et al.

Hum Immunol, 2019 Nov;80(11):906-907.
PMID: 31558331 DOI: 10.1016/j.humimm.2019.09.005

A total of 194 Southeast Asia Chinese from Peninsular Malaysia were genotyped for HLA-A, -B, -C -DRB1, and -DQB1 loci using polymerase chain reaction sequence-specific oligonucleotide probe hybridization methods. In this report, the HLA-B, HLA-DRB1 and HLA-DQB1 were in Hardy-Weinberg proportions (HWEP) (p > 0.05). We observed significant deviation from HWEP in HLA-A (p HLA-C (p 

Matched MeSH terms: HLA-DRB1 Chains/genetics*
HLA-A, -B, -C, -DRB1 and -DQB1 alleles and haplotypes in 951 Southeast Asia Malays from Peninsular Malaysia

Tan LK, Mohd-Farid B, Salsabil S, Heselynn H, Wahinuddin S, Lau IS, et al.

Hum Immunol, 2016 Oct;77(10):818-819.
PMID: 27370684 DOI: 10.1016/j.humimm.2016.06.022

A total of 951 Southeast Asia Malays from Peninsular Malaysia were genotyped for HLA-A, -B, -C -DRB1, and -DQB1 loci using polymerase chain reaction sequence-specific oligonucleotide probe hybridization methods. In this report, there were significant deviation from Hardy-Weinberg proportions for the HLA-A (p<0.0001), -B (p<0.0001), -DRB1 (p<0.0001) and -DQB1 (p<0.01) loci. Minor deviations from HWEP were detected for HLA-C (p=0.01). This genotype data was available in Allele Frequencies Network Database (AFND) Gonzalez-Galarza et al. (2015).

Matched MeSH terms: HLA-DRB1 Chains/genetics*
Human leukocyte antigen (HLA) class II association in chronic hepatitis B patients with hepatocellular carcinoma in a Malay population: A pilot study

Krishnan PB, Abdullah M, Hudu SA, Sekawi Z, Tan SS, Amin-Nordin S

Trop Biomed, 2019 Sep 01;36(3):703-708.
PMID: 33597492

Asian countries account for almost three quarter of hepatocellular carcinoma (HCC) reported globally and chronic hepatitis B infection is one of the main contributors. Clinical observations show that Malay patients with chronic hepatitis B and HCC tend to have a worse outcome, when compared to other two major races in Malaysia. The objectives of this study was to determine the frequency of human leukocyte antigen (HLA) class II alleles in chronic hepatitis B patients with HCC among Malays compared to the general population to identify potential associations of HLA alleles with this disease. HLA class II typing was performed in chronic hepatitis B patients with hepatocellular carcinoma (n=12) by -polymerase chain reaction, sequence specific primer (PCR-SSP) method. There were higher allelic frequencies of certain HLA-DQB1 and HLA-DRB1 alleles; HLA-DQB1*03 (07) (41.7%), and HLA-DRB1*12 (41.7% vs 28.6%) and compared to controls (41.7% vs 29.7%). However, there was no significant statistical correlation found when compared with the normal healthy general population. This study provides an insight into the HLA Class II association with chronic hepatitis B and hepatocellular carcinoma in Malays. However, findings from this study should be validated with a larger number of samples using a high resolution HLA typing.

Matched MeSH terms: HLA-DRB1 Chains/genetics*
The pattern of HLA-A, -B and -DRB1 alleles and haplotypes of four Malay sub-ethnic groups namely Kelantan, Champa, Patani and Mandailing Malays of Peninsular Malaysia

Allia S, Norazmi MN, Panneerchelvam S, Zafarina Z

Hum Immunol, 2019 Jul;80(7):423-424.
PMID: 30836128 DOI: 10.1016/j.humimm.2019.02.015

"Bumiputra" or "son of the soil" is a term used to represent the Malays and other indigenous populations of Malaysia. The Malays are Austronesian speaking population and originated from different parts of the Indo-Malay Archipelago. The migration of Malay population from different parts of Indo-Malay Archipelago were mainly due to trading purposes which shaped the current Malay sub-ethnic groups with unique culture and with distinctive dialects. In this study, HLA typing was carried out using Sequence-based Typing (SBT) method on 109 individuals comprising of four Malay sub-ethnic groups namely Kelantan (n = 28), Champa (n = 29), Patani (n = 25) and Mandailing (n = 27) Malays. The HLA data is available in the Allele Frequencies Net Database (AFND).

Matched MeSH terms: HLA-DRB1 Chains/genetics*
Fulltext HLA-DQ A1, -DQB1 and -DRB1 gene polymorphism--in Malay type 1 diabetes mellitus patients and their use for risk prediction

Rohana AG, Loh KC, Tin SK, Soh CH, Nazaimoon WM, Fong KY, et al.

Med J Malaysia, 2011 Jun;66(2):133-7.
PMID: 22106694

HLA-DQA1, -DQB1, and -DRB1 gene polymorphism were analyzed to study type 1 DM susceptibility in Malay patients from Southeast Asia (Malaysia and Singapore). Patients showed significant increases in the occurrence of DQA1*0501 (50.7% vs. 20.4%; RR = 3.97; Pc < 0.01), DQB1*0201 (48% vs. 19.1%; RR = 3.86; Pc < 0.05), and DRB1*0301 (38.7 vs. 6.8%; RR = 8.36; 95% Pc < 0.05). Conversely, significant decreases were noted in the occurrence of DQA1*0601 (14.7% vs. 35.2%; RR = 0.33; Pc = 0.008) and DQB1*0601 (4% vs. 23.5%; RR = 0.16; Pc < 0.05) in type 1 DM patients. Using a logistic regression model, we derived a risk prediction model for type 1 DM in our indigenous Malay population based on the identified HLA genotypes. The RR for type 1 DM increases by a factor of 5.68 for every unit increase in the number of DRB1*0301 allele (P < 0.001), and decreases by a factor of 0.18 per unit increase in the number of DQB1*0601 allele (P < 0.001). After adjusting for these two HLA genotypes, DQA1*0501, DQB1*0201 and DQA1*0601 were not statistically significant as risk predictors. The lower incidence of type 1 DM in the Malay population may be contributed by the genotypic combinations of DR and DQ genes as well as the linkage disequilibria between susceptible and protective alleles.

Matched MeSH terms: HLA-DRB1 Chains/genetics*
The association between HLA genes and radiological erosions in Malaysian patients with rheumatoid arthritis

Yeap SS, Mohd A, Kumar G, Kong KF, Chow SK, Goh EM, et al.

Autoimmunity, 2007 May;40(3):187-90.
PMID: 17453717 DOI: 10.1080/08916930701233755

OBJECTIVE:
To assess the relationship between the HLA-DRB1 genes with disease severity as assessed by radiological erosions in Malaysian patients with rheumatoid arthritis (RA).

METHODS:
In this cross-sectional study, we studied 61 RA patients who fulfilled the ACR criteria for the diagnosis of RA. HLA-DRB1 genotyping was performed by sequence specific primer (SSP) - PCR. Radiological grading and erosive score of the hands and wrists was calculated according to the Larsen-Dale method. Demographic data and treatment given to the patients were obtained from their case records.

RESULTS:
Fifty-six females and five males were studied from three ethnic groups. In 57 patients with erosions, rheumatoid factor was detected in 80%, HLA-DR4 in 40%, HLA-DRB1*0405 in 24% and shared epitope (SE) in 31%. The median delay in starting DMARDs was 24 months. The presence of rheumatoid factor, HLA-DR4 and HLA-DRB1*0405 were not significantly associated with a worse erosive score. Patients who possessed the SE had a higher erosive scores, compared to those who did not (p = 0.05). Concurrently, a delay in starting DMARD was associated with a high erosive score (p = 0.023, r = 0.348). However, after adjustment for the delay in starting DMARD, SE was no longer significantly associated with the erosive score.

CONCLUSIONS:
In these patients, the delay in starting DMARDs had a greater influence on the erosive score than SE alone. Whilst we cannot discount the contribution of the SE presence, we would advocate early usage of DMARDs in every RA patient to reduce joint erosions and future disability.

Matched MeSH terms: HLA-DRB1 Chains
HLA-DRB1 genes and susceptibility to rheumatoid arthritis in three ethnic groups from Malaysia

Kong KF, Yeap SS, Chow SK, Phipps ME

Autoimmunity, 2002 Jul;35(4):235-9.
PMID: 12482190

Worldwide population studies have generally agreed that rheumatoid arthritis (RA) is associated with a group of HLA-DRB1 alleles which share a common amino acid sequence at residues 70-74. This represents the first study to investigate the association of HLA-DRB1 genes with susceptibility to RA amongst Malay, Chinese and Indian ethnic groups in Malaysia. One hundred and thirty three RA patients and one hundred and sixty seven healthy controls were recruited. The HLA-DRB1 alleles were studied using the Phototyping method. The subtypes of HLA-DR4 were detected by "high resolution" PCR-SSP DRB1*04 typing techniques. The prevalence of HLA-DRB1*0405 was significantly higher in Malay patients with RA than in healthy controls (28.9 vs. 8.3%, p = 0.0016, OR = 4.48, 95% CI = 1.26-16.69). Similarly, DRB1*0405 was more common in Chinese RA patients than in controls (30.0 vs. 6.7%, p = 0.0029, OR = 6.00, 95% CI = 1.67-23.48). In addition, DRB1*0901 was a predisposing factor (32.0 vs. 6.7%,p = 0.0015, OR = 6.59, 95% CI = 1.85-25.64) and *0301/04 had a protective role (4.0vs. 25.0%, p = 0.00562, OR = 0.13, 95% CI = 0.02-0.62) in Malaysian Chinese RA. RA in Indians was associated with DRB1*1001 (51.1 vs. 8.5%,p = 0.00002, OR = 11.24, 95% CI = 3.13-44.18). DRB1*0701 (13.3 vs. 42.6%,p = 0.0022, OR = 2.73, 95% CI = 1.40-5.37) may have a protective effect. Therefore, in the Malaysian population, RA is primarily associated with the QRRAA motif, and we suggest that genetic factors play a crucial role in the pathogenesis of RA, compared to environmental factors.

Matched MeSH terms: HLA-DRB1 Chains
Fulltext Buccal swab as a suitable source of genomic DNA for screening of selected human leukocyte antigen (HLA) alleles

Vivek Prasad, Lam Yan Shim, Sethu Thakachy Subha, Fazlina Nordin, Maha Abdullah

Malaysian Journal of Medicine and Health Sciences, 2019;15(108):46-46.
MyJurnal

Introduction: Human leukocyte antigens (HLA) are a group of unique transmembrane glycoproteins that are ex-pressed on the surface of virtually all types of cells within the human body. These molecules are encoded by a set of highly polymorphic gene sequences known also as the major histocompatibility complex (MHC) and play an essential role in the presentation of antigenic peptides to immune cells for recognition and response. In recent years, various HLA alleles have been found to be associated with different autoimmune and inflammatory diseases such as rheumatoid arthritis, systemic lupus erythematosus (SLE) and allergic rhinitis. Identification of these alleles via HLA typing is necessary for initial screening and diagnosis purposes. Besides that, HLA typing is also used to determine compatibility matching between a donor and a recipient for tissue/organ transplantations in order to prevent graft rejection. Therefore, good quality and quantity of genomic DNA is required. In most scenarios, peripheral blood is chosen as the most reliable source of DNA for analysis, however this approach is seen as invasive and may cause pain and anxiety among the patients, particularly young children and weak subjects. Hence, derivation of genomic DNA from buccal cells as an alternative source material is becoming increasingly popular, especially in PCR-based genetic assays. Some of the most commonly described methods to collect buccal cells include using oral swabs, cytological brushes, mouthwashes and treated cards. Each technique yields varying quantities of DNA with diverse purity levels. In this study, we aim to evaluate the amount and purity of genomic DNA extracted from buccal swabs and brushes as well as blood for screening of selected HLA class II alleles. Methods: Cheek cell samples were col-lected using sterile foam tipped buccal swabs (Whatman) and buccal collection brushes (Gentra Puregene) whereas peripheral blood samples were withdrawn following routine venipuncture techniques. All samples were subjected to DNA extraction according to modified commercial kit protocols. Screening of selected HLA-DRB1 alleles was con-ducted via PCR with sequence-specific primers as established by Bunce et al. 1995. Results: There was no significant difference (p > 0.05) in the total DNA yield obtained from blood and buccal swab samples, which were 17.57μg (± 8.66) and 13.28μg (± 4.81), respectively. All samples exhibited similar 260/280 ratios of about ~1.80 (p > 0.05). However, buccal brush samples contributed the least amount of DNA (0.29μg, ± 0.12) compared to other sources (p < 0.05). The pure genomic DNA isolated from both blood and buccal swab samples were successfully typed for low resolution HLA-DRB1 alleles. Conclusion: Buccal swabs provide good quantity and quality of DNA for screening of HLA alleles with high accuracy and thus can be utilized as a non-invasive substitute for venipuncture.

Matched MeSH terms: HLA-DRB1 Chains
HLA-A, -B, -C, -DRB1 and -DQB1 alleles and haplotypes in 271 Southeast Asia Indians from Peninsular Malaysia

Nurul-Aain AF, Tan LK, Heselynn H, Nor-Shuhaila S, Eashwary M, Wahinuddin S, et al.

Hum Immunol, 2020 Jun;81(6):263-264.
PMID: 32312605 DOI: 10.1016/j.humimm.2020.04.004

A total of 271 Southeast Asia Indians from Peninsular Malaysia were genotyped for HLA-A, -B, -C, -DRB1, and -DQB1 loci using polymerase chain reaction sequence-specific oligonucleotide probe hybridization methods. In this report, HLA-B and HLA-DQB1 was in Hardy-Weinberg proportions (HWEP) (p > 0.05). We observed significant deviation from the HWEP for HLA-A (p HLA-C (p HLA-DRB1 (p

Matched MeSH terms: HLA-DRB1 Chains
Fulltext Shared epitope alleles remain a risk factor for anti-citrullinated proteins antibody (ACPA)--positive rheumatoid arthritis in three Asian ethnic groups

Too CL, Padyukov L, Dhaliwal JS, Lundström E, Yahya A, Muhamad NA, et al.

PLoS One, 2011;6(6):e21069.
PMID: 21698259 DOI: 10.1371/journal.pone.0021069

BACKGROUND: To investigate the associations between HLA-DRB1 shared epitope (SE) alleles and rheumatoid arthritis in subsets of rheumatoid arthritis defined by autoantibodies in three Asian populations from Malaysia.
METHODS: 1,079 rheumatoid arthritis patients and 1,470 healthy controls were included in the study. Levels of antibodies to citrullinated proteins (ACPA) and rheumatoid factors were assessed and the PCR-SSO method was used for HLA-DRB1 genotyping.
RESULTS: The proportion of ACPA positivity among Malay, Chinese and Indian rheumatoid arthritis patients were 62.9%, 65.2% and 68.6%, respectively. An increased frequency of SE alleles was observed in ACPA-positive rheumatoid arthritis among the three Asian ethnic groups. HLA-DRB1*10 was highly associated with rheumatoid arthritis susceptibility in these Asian populations. HLA-DRB1*0405 was significantly associated with susceptibility to rheumatoid arthritis in Malays and Chinese, but not in Indians. HLA-DRB1*01 did not show any independent effect as a risk factor for rheumatoid arthritis in this study and HLA-DRB1*1202 was protective in Malays and Chinese. There was no association between SE alleles and ACPA- negative rheumatoid arthritis in any of the three Asian ethnic groups.
CONCLUSION: The HLA-DRB1 SE alleles increase the risk of ACPA-positive rheumatoid arthritis in all three Asian populations from Malaysia.

Matched MeSH terms: HLA-DRB1 Chains

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