HLA antigens in Malay patients with systemic lupus erythematosus: association with clinical and autoantibody expression

Prevalence and risk factors of antibodies towards HLA Class I and Class II in Malaysian renal transplant candidates

Antibody-mediated rejection (AMR) still persists as the major hurdle towards successful renal allograft survival. This paper aims to report on the HLA antibody landscape of renal transplant candidates in Malaysia. A total of 2,219 adult samples from 2016 to 2019 were analysed for anti-HLA antibodies using solid-phase assay. Our findings highlight the prevalence and risk factors for antibodies against HLA antigens in renal transplant settings, which could be beneficial for selecting compatible recipients from deceased organ donors. To the best of our knowledge, this study is the first to demonstrate that ethnic Malay and Chinese showed significantly higher prevalence of anti-HLA antibodies. Based on our multivariate analysis: (i) female gender was associated with higher risk for panel reactive antibodies (PRAs) against Class I, Class II, and Class I and II (p < 0.001); (ii) older patients (≥ 38 years old) were associated with higher risk of positivity against Class I, Class II and Class I and II (p < 0.001); (iii) Malays showed significant association with Class II antibodies (p = 0.035); Chinese patients presented with higher risk of PRA positivity against Class II (p < 0.001) and Class I and II (p = 0.01); Indians were significantly associated with higher risk of HLA antibody sensitization against Class I (p = 0.022), Class II (p = 0.026) and Class I and II (p = 0.05). Thus, our findings suggested that female gender, older age (≥ 38 years old) and ethnicity may serve as independent risk factors for HLA antibody sensitization in adult renal transplant candidates.

Prevalence, causes and treatments of allergic rhinitis in Malaysia: a literature review

Recently, allergic rhinitis (AR) cases have been surging rapidly in many developing countries. However, the prevalence, risk factors and treatment modalities for AR within the Malaysian population have not been thoroughly evaluated. The present study aimed to provide a complete review of literature on allergic rhinitis in Malaysia. Available data indicated that the prevalence of AR varied across different age groups and regions in Malaysia, but there is an increasing trend among the younger population. The key contributing factor is exposure and sensitization towards several airborne allergens, mainly house dust mites, cat fur and fungi, with possible genetic predispositions. In addition, variations in the symptom severity may be associated with racial orientations. For management of the disease, standard prescriptions of conventional drugs (antihistamines, intranasal corticosteroids and nasal decongestants) remain as the treatment of choice. A small proportion of the native residents tend to resort to alternative approaches of self-healing through aromatherapy and natural food consumption such as tiger’s milk mushroom and Tualang honey. In conclusion, the increase in the cases of AR in Malaysia is due to environmental and genetic factors which requires proper medical intervention as treatment strategies. The utilization of holistic approaches requires further studies and clear understanding prior to their integration into the standard of care. There are still many gaps in the knowledge and management of allergic rhinitis which demands further attention from the research community.

Human leucocyte antigens profiling in Malay female patients with systemic lupus erythematosus: are we the same or different?

OBJECTIVE

SLE is a heterogeneous autoimmune disease, in terms of clinical presentation, incidence and severity across diverse ethnic populations. We investigated the human leucocyte antigens (HLA) profile (ie, HLA-A, HLA-B and HLA-C, HLA-DRB1, HLA-DQA1, HLA-DQB1, HLA-DPA1 and HLA-DPB1) in Malaysian Malay female patients with SLE and determined the generalisability of the published HLA risk factors across different ethnic populations globally including Malaysia.

METHODS

One hundred Malay female patients with SLE were recruited between January 2016 and October 2017 from a nephrology clinic. All patients were genotyped for HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQA1, HLA-DQB1, HLA-DPA1 and HLA-DPB1 alleles using PCR sequence-specific oligonucleotides method on Luminex platform. A total of 951 HLA genotyped population-based Malay control subjects was used for association testing by means of OR with 95% CIs.

RESULTS

Our findings convincingly validated common associations between HLA-A*11 (OR=1.65, p=3.36×10^-3, corrected P (Pc)=4.03×10^-2) and DQB1*05:01 (OR=1.56, p=2.02×10^-2, Pc=non-significant) and SLE susceptibility in the Malay population. In contrast, DQB1*03:01 (OR=0.51, p=4.06×10^-4, Pc=6.50×10^-3) were associated with decreased risk of SLE in Malay population. Additionally, we also detected novel associations of susceptibility HLA genes (ie, HLA-B*38:02, DPA1*02:02, DPB1*14:01) and protective HLA genes (ie, DPA1*01:03). When comparing the current data with data from previously published studies from Caucasian, African and Asian populations, DRB1*15 alleles, DQB1*03:01 and DQA1*01:02 were corroborated as universal susceptibility and protective genes.

CONCLUSIONS

This study reveals multiple HLA alleles associated with susceptibility and protection against risk of developing SLE in Malay female population with renal disorders. In addition, the published data from different ethnic populations together with our study further support the notion that the genetic effects from association with DRB1*15:01/02, DQB1*03:01 and DQA1*01:02 alleles are generalised to multiple ethnic populations of Caucasian, African and Asian descents.

HLA-DRB1*04 as a Risk Allele to Systemic Lupus Erythematosus and Lupus Nephritis in the Malay Population of Malaysia

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease afflicting multiple organs. Lupus nephritis (LN) is a serious complication of SLE and remains a major cause of mortality and morbidity. Curative therapy remains unavailable as etiology from genetic and environmental factors is still unclear. The present study was conducted to elucidate the link between HLA-DRB1 gene polymorphisms with SLE and LN through clinical and laboratory/biological presentations in a population of Malaysian Malay females with SLE. A total of 100 Malay female SLE patients inclusive of 70 SLE patients without LN and 30 patients with LN were included in this study. HLA-DRB1 allele examination in SLE patients was performed using PCR-SSO, and the alleles' frequencies were compared with 951 publicly available datasets representing Malay healthy controls in Malaysia. Cytokines and free radical levels were detected by ELISA and bead-based multiplexed Luminex assays. The association between HLA-DRB1 alleles with clinical and serological manifestations and immune mediators was analyzed using different statistical approaches whenever applicable. Our study showed that HLA-DRB1^*0405, HLA-DRB1^*1502, and HLA-DRB1^*1602 were associated with the increased risk of SLE while HLA-DRB1^*1201 and HLADRB1^*1202 alleles were associated with a lower risk of SLE development. Furthermore, HLA-DRB1^*04 showed significant association to LN and arthritis while HLA-DRB1^*15 was significantly associated with oral ulcer in Malay SLE patients. Association analysis of HLA-DRB1^*04 with clinical and biological factors revealed that HLA-DRB1^*04 was significantly associated with Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) scores, anti-nuclear antibody (ANA), C-reactive protein (CRP) in the blood, and total protein in the urine. SLE carriers with the HLA-DRB1^*04 allele were significantly correlated to the increased levels of cytokines (IFN-y, GM-CSF, IL-17F, IL-18, IL-21, and VEGF) and were significantly showing negative correlation to IL-5 and free radicals (LPO and catalase enzyme) levels compared to SLE carriers without HLA-DRB1^*04 allele. The results suggested that disease severity in SLE may be determined by HLA-DRB1 alleles. The risk of HLA-DRB1^*04 allele with LN was supported by the demonstration of an intense inflammatory response in Malay SLE patients in Malaysia. More studies inclusive of a larger and multiple SLE cohorts in the future are warranted to validate these findings.

HLA-DRB1 gene polymorphisms in Iranian children with Henoch-Schönlein purpura

BACKGROUND

People of all ages can suffer from Henoch-Schönlein purpura (HSP), but it is the most common vasculitis in childhood. The most important involving gene is located on chromosome 6p21.3, a region coding for human leukocyte antigens (HLAs). Among HLA genes, because of the high rate of polymorphisms, HLA-DRB1 is estimated to have a strong association with HSP. In this study, we aimed to assess the association of HLA-DRB1 alleles with HSP in Iranian children.

MATERIALS AND METHODS

This study consisted of thirty Iranian children with HSP and 35 healthy controls. Genomic DNA was extracted, and HLA typing was performed by polymerase chain reaction with sequence-specific primers technique.

RESULTS

The results have shown that HLA-DRB1*01 and HLA-DRB1*11 (P = 0.002, odds ratio [OR] = 7.579, confidence interval [CI] = 1.934-29.697 and P = 0.039, OR = 3.333, CI = 1.030-10.788), respectively, are the most frequent alleles associated with HSP in Iranian children population. The frequency of other alleles was not significantly different in both groups. The results also show no correlation between HLA types and disease manifestations.

CONCLUSION

According to these results, there is an association between HLA-DRB1*01 and HLA-DRB1*11 gene polymorphisms and susceptibility to HSP in our study group.

Development of autoantibodies precedes clinical manifestations of autoimmune diseases: A comprehensive review

The etiology of autoimmune diseases is due to a combination of genetic predisposition and environmental factors that alter the expression of immune regulatory genes through various mechanisms including epigenetics. Both humoral and cellular elements of the adaptive immune system play a role in the pathogenesis of autoimmune diseases and the presence of autoantibodies have been detected in most but not all autoimmune diseases before the appearance of clinical symptoms. In some cases, the presence or levels of these autoantibodies portends not only the risk of developing a corresponding autoimmune disease, but occasionally the severity as well. This observation is intriguing because it suggests that we can, to some degree, predict who may or may not develop autoimmune diseases. However, the role of autoantibodies in the pathogenesis of autoimmune diseases, whether they actually affect disease progression or are merely an epiphenomenon is still not completely clear in many autoimmune diseases. Because of these gaps in our knowledge, the ability to accurately predict a future autoimmune disease can only be considered a relative risk factor. Importantly, it raises the critical question of defining other events that may drive a patient from a preclinical to a clinical phase of disease.

Value of HLA-DR genotype in systemic lupus erythematosus and lupus nephritis: a meta-analysis

AIM

Human leukocyte antigen (HLA)-DRB1 allele polymorphisms have been reported to be associated with systemic lupus erythematosus (SLE) susceptibility, but the results of these previous studies have been inconsistent. The purpose of the present study was to systematically summarize and explore whether specific HLA-DRB1 alleles confer susceptibility or resistance to SLE and lupus nephritis.

METHODS

This review was guided by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) approach. A comprehensive search was made for articles from PubMed, Medline, Elsevier Science, Springer Link and Cochrane Library database. A total of 25 case-control studies on the relationship between gene polymorphism of HLA-DRB l and SLE were performed and data were analyzed and processed using Review Manager 5.2 and Stata 11.0.

RESULTS

At the allelic level, HLA-DR4, DR11 and DR14 were identified as protective factors for SLE (0.79 [0.69,0.91], P < 0.001; 0.72 [0.60, 0.85], P < 0.0001; 0.47 [0.59, 0.95], P < 0.05, respectively). HLA-DR3, DR9, DR15 were potent risk factors for SLE (1.88 [1.58, 2.23], P < 0.001; 1.24 [1.07, 1.45], P < 0.05; 1.25 [1.10, 1.43], P < 0.001, respectively). However, HLA-DR8 was not statistically significant between the SLE group and control group (OR, 1.11 [0.96, 1.30], P > 0.05). DR4 and 11 (OR, 0.55 [0.39, 0.79], P < 0.01; 0.60 [0.37, 0.96], P < 0.05, respectively) conferred a significant protective effect for lupus nephritis. DR3 and DR15 (OR, 2.00 [1.49, 2.70], P < 0.05; 1.60 [1.21, 2.12], P < 0.001, respectively) were at a high risk of developing lupus nephritis. HLA-DR8, DR9 and DR14 (OR, 1.47 [0.9, 2.33], P > 0.05; 0.90 [0.64, 1.27], P > 0.05; 0.61 [0.36, 1.03], P > 0.05, respectively) were not statistically significant between the lupus nephritis and control groups.

CONCLUSIONS

The HLA-DR4, DR11, DR14 alleles might be protective factors for SLE and HLA-DR3, DR9, DR15 were potent risk factors. In addition, HLA-DR4 and DR11 alleles might be protective factors for lupus nephritis and DR3 and DR15 suggest a risk role. These results proved that HLA-DR3, DR15, DR4 and DR11 might be identified as predictors for lupus nephritis and SLE.

Characteristics and outcome of autoimmune liver disease in Asian children

BACKGROUND

Little is known about autoimmune liver disease (AILD) in Asian children. We studied the clinical features and predictors of outcome in childhood AILD in an Asian population.

METHODS

Retrospective review of AILD [autoimmune hepatitis type 1 and 2 (AIH1, AIH2), primary sclerosing cholangitis (PSC) and autoimmune sclerosing cholangitis (ASC)] seen at two pediatric liver units in Malaysia.

RESULTS

At presentation, 17 (56%) of the 32 children [19 females, 59%; median (range) age 7.7 (1.8-15.5) years] with AILD (AIH1 = 18, AIH2 = 5, PSC = 0, ASC = 9) had liver cirrhosis. At final review [median (range) duration of follow-up 4.8 (0.4-12) years], 24 patients (75%) survived with a native liver. Twenty-one (66%) were in remission; 19 (AIH1 = 11; AIH2 = 4, ASC = 4) were on prednisolone and/or azathioprine, one on cyclosporine and another on mycophenolate mofetil. Three (AIH1 = 3) were in partial remission. Of the two who underwent liver transplantation (LT; 6.5%; both ASC), one died of primary graft failure after LT. Six patients (19%) died without LT (acute liver failure, n = 1; end-stage liver disease, n = 5). The overall survival rate (native liver and survival post-LT) was 78%. A delay in seeking treatment adversely affected the final outcome [survival with native liver vs. LT or death (duration between onset of disease and treatment; median ± standard error) = 2.5 ± 2.9 months vs. 24.0 ± 13.3 months; p = 0.012].

CONCLUSIONS

Although remission was achieved in the majority of patients with prednisolone and/or azathioprine therapy, delay in seeking diagnosis and treatment adversely affects the outcome of childhood AILD in Malaysia.

Evaluation of SLE Susceptibility Genes in Malaysians

Systemic Lupus Erythematosus (SLE) is a clinically heterogeneous autoimmune disease with strong genetic and environmental components. Our objective was to replicate 25 recently identified SLE susceptibility genes in two distinct populations (Chinese (CH) and Malays (MA)) from Malaysia. We genotyped 347 SLE cases and 356 controls (CH and MA) using the ImmunoChip array and performed an admixture corrected case-control association analysis. Associated genes were grouped into five immune-related pathways. While CH were largely homogenous, MA had three ancestry components (average 82.3% Asian, 14.5% European, and 3.2% African). Ancestry proportions were significantly different between cases and controls in MA. We identified 22 genes with at least one associated SNP (P < 0.05). The strongest signal was at HLA-DRA (P_Meta = 9.96 × 10⁻⁹; P_CH = 6.57 × 10⁻⁸, P_MA = 6.73 × 10⁻³); the strongest non-HLA signal occurred at STAT4 (P_Meta = 1.67 × 10⁻⁷; P_CH = 2.88 × 10⁻⁶, P_MA = 2.99 × 10⁻³). Most of these genes were associated with B- and T-cell function and signaling pathways. Our exploratory study using high-density fine-mapping suggests that most of the established SLE genes are also associated in the major ethnicities of Malaysia. However, these novel SNPs showed stronger association in these Asian populations than with the SNPs reported in previous studies.

HLA variants rs9271366 and rs9275328 are associated with systemic lupus erythematosus susceptibility in Malays and Chinese

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 < 0.05). As for 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 < 1 and p value <0.05. Both SNPs did not show associations to SLE in Indians. D' and r (2) values for the two SNPs in LD analysis were 0.941 and 0.065, respectively, with haplotype GC and AT being significantly associated with SLE (p < 5.0 × 10(-4)) after 10,000 permutations were performed. The MDR test clustered the genotype combinations of GG and CC, and AG and CC of rs9271366 and rs9275328, accordingly, as high-risk group, and the two SNPs interacted redundantly by removing 1.96% of the entropy.

CONCLUSIONS

Our findings suggest that in addition to some classical HLA variants, rs9271366 and rs9275328 are additional polymorphisms worth considering in the Malaysian and possibly in a larger Asian SLE scenario.

Role of MHC-linked susceptibility genes in the pathogenesis of human and murine lupus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies against nuclear antigens and a systemic inflammation that can damage a broad spectrum of organs. SLE patients suffer from a wide variety of symptoms, which can affect virtually almost any tissue. As lupus is difficult to diagnose, the worldwide prevalence of SLE can only be roughly estimated to range from 10 and 200 cases per 100,000 individuals with dramatic differences depending on gender, ethnicity, and location. Although the treatment of this disease has been significantly ameliorated by new therapies, improved conventional drug therapy options, and a trained expert eye, the underlying pathogenesis of lupus still remain widely unknown. The complex etiology reflects the complex genetic background of the disease, which is also not well understood yet. However, in the past few years advances in lupus genetics have been made, notably with the publication of genome-wide association studies (GWAS) in humans and the identification of susceptibility genes and loci in mice. This paper reviews the role of MHC-linked susceptibility genes in the pathogenesis of systemic lupus erythematosus.

Genetic risk factors of systemic lupus erythematosus in the Malaysian population: a minireview

SLE is an autoimmune disease that is not uncommon in Malaysia. In contrast to Malays and Indians, the Chinese seem to be most affected. SLE is characterized by deficiency of body's immune response that leads to production of autoantibodies and failure of immune complex clearance. This minireview attempts to summarize the association of several candidate genes with risk for SLE in the Malaysian population and discuss the genetic heterogeneity that exists locally in Asians and in comparison with SLE in Caucasians. Several groups of researchers have been actively investigating genes that are associated with SLE susceptibility in the Malaysian population by screening possible reported candidate genes across the SLE patients and healthy controls. These candidate genes include MHC genes and genes encoding complement components, TNF, FcγR, T-cell receptors, and interleukins. However, most of the polymorphisms investigated in these genes did not show significant associations with susceptibility to SLE in the Malaysian scenario, except for those occurring in MHC genes and genes coding for TNF-α, IL-1β, IL-1RN, and IL-6.

HLA-A*11 and novel associations in Malays and Chinese with systemic lupus erythematosus

We investigated the association of the HLA genes in Malaysian patients with systemic lupus erythematosus (SLE) and their associations with the clinical manifestations in 160 SLE patients (99 Chinese and 61 Malays) and 107 healthy control individuals (58 Chinese and 49 Malays) were studied. Sequence specific primer amplification (PCR-SSP) phototyping techniques were used to analyse 25 HLA-A allele groups, 31 HLA-DR allele groups and 9 HLA-DQ allele groups. Appreciable increases in allele frequencies of HLA-A*11, DRB1*0701, DRB1*1601-1606, DRB5*01-02 and DQB1*05, and decrease in HLA-DRB1*1101-1121, 1411, DRB1*1201-3, DRB1*1301-22, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 1304 in SLE patients compared with healthy control individuals. However, after Bonferroni correction (p(c)<0.05) only HLA-A*1101, 1102, DRB5*01-02, DQB1*05, DRB1*1201-3, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 0304 remained significant. Allele frequencies of DRB1*0701 and DRB4*0101101, 0102, 0103, DQB1*05, DRB1*1301-22, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 0304 were significantly increased in Malay SLE patients compared with healthy control individuals. In contrast, Chinese SLE patients had increased allele frequencies of DRB1*1601-1606, DQB1*05, DRB1*1201-3, DRB3*0101, 0201, 0202, 0203, 0301, DRB3*0101, 0201, 0202, 0203, 0301 and DQB1*0301, 0304 compared with healthy control individuals. HLA-A*6801-02 and DRB1*1601-1606 frequencies appeared elevated in a subset of patients with serositis and DRB1* 0401-1122 frequency was elevated in those displaying neurologic disorder. However, unequivocal evidence of these associations would require investigation of substantially larger cohorts. On the whole, our findings suggest that HLA allele associations with SLE are race specific in Malays and Chinese.

Current advances in lupus genetic and genomic studies in Asia

The genetic components in systemic lupus erythematosus (SLE) have long been established, however, it has been unclear for many years whether the same genetic risk factors for SLE are shared across different ethnic groups. Over the past few years, a number of genetic and genomic studies have been conducted in Asian populations to address this question. These studies have demonstrated that genetic heterogeneity does exist in SLE across different ethnic groups. With these studies, it has been established that a number of genes associated with SLE in Caucasians are also risk factors in Asians: HLA class II genes, STAT4, BANK1, BLK, IRF5, TNFSF4, ITGAM, etc., while there are also novel genetic risk factors identified by these studies in Asians, for instance, the ETS1 and WDFY4 in Chinese. For the genomic studies, the interferon signature has been confirmed as a major lupus molecular phenotype in Asians the same as in Caucasians; microRNA expression profiling and its novel role in regulating the interferon pathway has been first revealed in Asians. Further understanding of the function of lupus disease genes and delineating the key molecular pathway(s) will enhance the development of novel therapeutic targets and biomarkers for individualized clinical management for lupus patients.