HLA-DRB1 alleles influence clinical phenotypes in Japanese patients with ulcerative colitis

The role of human leukocyte antigen in HTLV-1 infection and progression to ATLL and HAM/TSP: a systematic review and meta-analysis

BACKGROUND

Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that leads to lifelong infection and multiple diseases, including HAM/TSP and ATLL. Despite extensive research, the exact pathophysiology of HTLV infection and its related diseases is enigmatic. In this study, we aimed to review and analyze the effect of different HLA alleles as protective or predisposing factors in HTLV-1 infection and its progression to related diseases.

METHOD

Three databases (PubMed, Web of Science, and Scopus) were searched for eligible studies. Twenty-five papers with 7279 participants were included in the quantitative analysis. The relevant data were extracted, and 198 meta-analyses were conducted on each reported HLA and population.

RESULTS

The results of our investigation suggest 3 HLAs with preventive effects against HTLV infection, including HLA-B*35, DRB1*09, and DRB1*16. Also, HLA-DQB1*05:01 might prevent HTLV progression to ATLL. In contrast, HLA-DRB1*13 is more prevalent in ATLL patients than HTLV carriers. Additionally, our results propound that carriers of HLA-A*28, B*54, C*07, DQB1*03:01, and DRB1*07:01 are at higher risk, and carriers of HLA-A*30, B*37, B*40, B*44, C*08, DQB1*06:02, and DRB1*15:01 are in lower risk of HTLV progression to HAM/TSP. We concluded that the mentioned HLA alleles are potential biomarkers of HTLV infection and its progression to related diseases.

Multi-factor mediated functional modules identify novel classification of ulcerative colitis and functional gene panel

Ulcerative colitis is a chronic, idiopathic, and inflammatory disease of the rectal and colonic mucosa, the behavior of which is of heterogeneity in individuals. Here, we explored the multifactor-mediated functional modules associated with ulcerative colitis classification in the whole genome. Datasets downloaded from the GEO database were used to identify differentially expressed genes between ulcerative colitis patients and healthy individuals initially, followed by acquisition of the remaining ulcerative colitis -related genes from the OMIM and STRING databases. The results identified 914 ulcerative colitis-related genes, of which 60 were differentially expressed genes obtained from GEO datasets. Through weighted co-expression network analysis of ulcerative colitis-related genes, four modules were obtained, three of which were related to ulcerative colitis. Following interactions between microRNA, long noncoding RNA, transcription factors, and module hub genes were predicted and used to construct ulcerative colitis multifactor networks. Additionally, we performed consensus clustering of the ulcerative colitis samples. The results revealed that ulcerative colitis could be divided into four subtypes, with six hub genes identified as potential biomarkers for classification. These findings offer novel insights into ulcerative colitis and a basis for disease classification of ulcerative colitis.

Review article: the genetics of the human leucocyte antigen region in inflammatory bowel disease

BACKGROUND

The human leucocyte antigen (HLA) complex, located at chromosome 6p21.3 is a highly polymorphic region containing the classical class I and II HLA genes. The region is highly associated with inflammatory bowel disease (IBD), largely through genome-wide association studies (GWAS).

AIMS

To review the role of HLA in immune function, summarise data on risk/protective HLA genotypes for IBD, discuss the role of HLA in IBD pathogenesis, treatment and examine limitations that might be addressed by future research.

METHODS

An organised search strategy was used to collate articles describing HLA genes in IBD, including Crohn's disease and ulcerative colitis.

RESULTS

All classical HLA genes with variation (including HLA-A, B, C, DRB1, DQA1, DQB1, DPA1 and DPB1) harbour IBD-associated genotypes. The most implicated gene is HLA-DRB1, with HLA-DRB1*03:01 the most associated risk allele in both Crohn's disease and ulcerative colitis. Elucidating precise disease associations is challenging due to high linkage disequilibrium between HLA genotypes. The mechanisms by which risk alleles cause disease are multifactorial, with the best evidence indicating structural and electrostatic alteration impacting antigen binding and downstream signalling. Adverse medication events have been associated with HLA genotypes including with thiopurines (pancreatitis) and anti-TNF agents (antibody formation).

CONCLUSIONS

The HLA complex is associated with multiple risk/protective alleles for IBD. Future research utilising long-read technology, ascertainment of zygosity and integration in disease modelling will improve the functional understanding and clinical translation of genetic findings.

Interstitial nephritis associated with ulcerative colitis in monozygotic twins

Although renal impairment is a rare complication of ulcerative colitis (UC), interstitial nephritis can occur as an idiosyncratic reaction to 5-aminosalicylate (5-ASA) treatment for UC. Monozygotic twins developed UC at ages 49 and 51, and they were separately treated at different medical institutes. They did not know that they had the same disease and were treated with the same drug (5-ASA). During the course of 5-ASA treatment, renal impairment diagnosed as interstitial nephritis occurred in both. Granulocyte/monocyte adsorption was initiated, UC remission was achieved and renal function deterioration subsided in both. Drug or treatment responses may be concordant in monozygotic twins with UC. Careful review is important before treatment to avoid serious adverse events.

Predicting outcomes in acute severe ulcerative colitis

Response to corticosteroid treatment in acute severe ulcerative colitis (ASUC) has changed very little in the past 50 years. Predicting those at risk at an early stage helps stratify patients into those who may require second line therapy or early surgical treatment. Traditionally, risk scores have used a combination of clinical, radiological and biochemical parameters; established indices include the 'Travis' and 'Ho' scores. Recently, inflammatory bowel disease genetic risk alleles have been built into models to predict outcome in ASUC. Given the multifactorial nature of inflammatory bowel disease pathogenesis, in the future, composite scores integrating clinical, biochemical, serological, genetic and other '-omic' data will be increasingly investigated. Although these new genetic prediction models are promising, they have yet to supplant traditional scores, which remain the best practice. In this modern era of rescue therapies in ASUC, robust scoring systems to predict failure of ciclosporine and infliximab must be devised.

Pathogenesis, diagnosis, and management of ulcerative proctitis, chronic radiation proctopathy, and diversion proctitis

Chronic proctitis refers to persistent or relapsing inflammation of the rectum, which results from a wide range of etiologies with various pathogenic mechanisms. The patients may share similar clinical presentations. Ulcerative proctitis, chronic radiation proctitis or proctopathy, and diversion proctitis are the 3 most common forms of chronic proctitis. Although the diagnosis of these disease entities may be straightforward in the most instances based on the clinical history, endoscopic, and histologic features, differential diagnosis may sometimes become problematic, especially when their etiologies and the disease processes overlap. The treatment for the 3 forms of chronic proctitis is different, which may shed some lights on their pathogenetic pathway. This article provides an overview of the latest data on the clinical features, etiologies, diagnosis, and management of ulcerative proctitis, chronic radiation proctopathy, and diversion proctitis.

Polymorphisms of HLA-DRB1, -DQA1 and -DQB1 in inhabitants of Astana, the capital city of Kazakhstan

BACKGROUND

Kazakhstan has been inhabited by different populations, such as the Kazakh, Kyrgyz, Uzbek and others. Here we investigate allelic and haplotypic polymorphisms of human leukocyte antigen (HLA) genes at DRB1, DQA1 and DQB1 loci in the Kazakh ethnic group, and their genetic relationship between world populations.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 157 unrelated Kazakh ethnic individuals from Astana were genotyped using sequence based typing (SBT-Method) for HLA-DRB1, -DQA1 and -DQB1 loci. Allele frequencies, neighbor-joining method, and multidimensional scaling analysis have been obtained for comparison with other world populations. Statistical analyses were performed using Arlequin v3.11. Applying the software PAST v. 2.17 the resulting genetic distance matrix was used for a multidimensional scaling analysis (MDS). Respectively 37, 17 and 19 alleles were observed at HLA-DRB1, -DQA1 and -DQB1 loci. The most frequent alleles were HLA-DRB1*07:01 (13.1%), HLA-DQA1*03:01 (13.1%) and HLA-DQB1*03:01 (17.6%). In the observed group of Kazakhs DRB1*07:01-DQA1*02:01-DQB1*02:01 (8.0%) was the most common three loci haplotype. DRB1*10:01-DQB1*05:01 showed the strongest linkage disequilibrium. The Kazakh population shows genetic kinship with the Kazakhs from China, Uyghurs, Mongolians, Todzhinians, Tuvinians and as well as with other Siberians and Asians.

CONCLUSIONS/SIGNIFICANCE

The HLA-DRB1, -DQA1 and -DQB1 loci are highly polymorphic in the Kazakh population, and this population has the closest relationship with other Asian and Siberian populations.

Characteristics of Japanese inflammatory bowel disease susceptibility loci

BACKGROUND

There are substantial differences in inflammatory bowel disease (IBD) genetics depending on the populations examined. We aimed to identify Japanese population-specific or true culprit susceptibility genes through a meta-analysis of past genetic studies of Japanese IBD.

METHODS

For this study, we reviewed 2,703 articles. The review process consisted of three screening stages: we initially searched for relevant studies and then relevant single nucleotide polymorphisms (SNPs). Finally, we adjusted them for the meta-analysis. To maximize our chances of analysis, we introduced proxy SNPs during the first stage. To minimize publication bias, no significant SNPs and solitary SNPs without pairs were combined to be reconsidered during the third stage. Additionally, two SNPs were newly genotyped. Finally, we conducted a meta-analysis of 37 published studies in 50 SNPs located at 22 loci corresponding to the total number of 4,853 Crohn's disease (CD), 5,612 ulcerative colitis (UC) patients, and 14,239 healthy controls.

RESULTS

We confirmed that the NKX2-3 polymorphism is associated with common susceptibility to IBD and that HLA-DRB1*0450 alleles increase susceptibility to CD but reduce risk for UC while HLA-DRB1*1502 alleles increase susceptibility to UC but reduce CD risk. Moreover, we found individual disease risk loci: TNFSF15 and TNFα to CD and HLA-B*5201, and NFKBIL1 to UC. The genetic risk of HLA was substantially high (odds ratios ranged from 1.54 to 2.69) while that of common susceptibility loci to IBD was modest (odds ratio ranged from 1.13 to 1.24).

CONCLUSIONS

Results indicate that Japanese IBD susceptibility loci identified by the meta-analysis are closely associated with the HLA regions.

Association of HLA-DRB1 alleles and anti-neutrophil cytoplasmic antibodies in Han and Uyghur patients with ulcerative colitis in China

OBJECTIVE

We aimed to study the association between HLA-DRB1 alleles and anti-neutrophil cytoplasmic antibodies (ANCA) among Uyghur and Han patients with ulcerative colitis (UC) in China.

METHODS

Altogether 160 UC patients and 466 healthy controls of Uyghur and Han groups residing in the Xinjiang Uyghur Autonomous Region of China were included. HLA-DRB1 variants were identified from genomic DNA using polymerase chain reaction and gene sequencing. Serum ANCA were determined by indirect immunofluorescence assay.

RESULTS

Among the Uyghur populations, the HLA-DRB1*08 gene frequency was lower in the UC patients than in the control group (P = 0.012, OR 0.12, 95% CI 0.02-0.91); however, that of HLA-DRB1*13 was much higher in the UC patients than in the controls (P = 0.001, OR 4.32, 95% CI 1.92-9.74). In Han patients with UC, there was no significant difference in HLA-DRB1 frequency between UC patients and healthy controls. The positive rate of ANCA in Uyghur patients with UC was significantly higher than in Han UC patients (P = 0.026), and ANCA positivity was associated with an increased frequency of HLA-DRB1*13 in Uyghur UC patients, but no such difference was observed in the Han patients.

CONCLUSIONS

Genetic polymorphisms of the HLA-DRB1*08 and *13 may contribute to the clinical heterogeneity of UC between Uyghur and Han UC patients in China. In Uyghur UC patients, HLA-DRB1*13 may be correlated with ANCA positivity.

Difference in DRB1* gene polymorphisms between Han and Uyghur ulcerative colitis patients in China

AIM: To evaluate the association between HLA-DRB1 alleles and Han and Uyghur ulcerative colitis (UC) patients residing in the Xinjiang Uyghur Autonomous Region of China.

METHODS: In this study, 102 UC patients (53 Han including 22 men and 31 women, and 49 Uyghur patients including 25 men and 24 women; aged 48.07 ± 15.83 years) and 310 age- and sex-matched healthy controls were enrolled in the Department of Gastroenterology, Xinjiang People’s Hospital of China from January 2010 to May 2011. UC was diagnosed based on the clinical, endoscopic and histological findings following Lennard-Jones criteria. Blood samples were collected and genomic DNA was extracted by routine laboratory methods, and both polymerase chain reaction and gene sequencing were used to identify HLA-DRB1 allele variants. The potential association between genetic variation and UC in Han and Uyghur patients was examined. There were no statistical differences in HLA-DRB1 allele frequencies in Han UC patients.

RESULTS: There was no significant difference in the sex ratio between the controls and UC patients (P = 0.740). In Han patients with UC (n = 53), HLA-DRB1 *03, *13 allele frequencies were lower than in healthy controls (n = 161), but not statistically significant, and HLA-DRB1*04*11*14 allele frequencies were higher than in healthy controls, but without statistical significance. Differences between Uyghur UC patients and the control group were observed for HLA-DRB1*04 and HLA-DRB1*13, both showed a greater frequency in UC patients (10.21% vs 2.69%, P = 0.043; 14.29% vs 4.03%, P = 0.019). HLA-DRB1*14 also showed a greater frequency in UC patients (14.29% vs 2.69%, P = 0.006). The frequencies of DRB1*04, *13*14 alleles were increased in Uyghur UC patients compared with normal controls. The frequency of DRB1 * 08 was decreased in Uyghur UC patients compared with normal controls. HLA-DRB1 alleles showed no association with UC in Han patients. There were no statistical differences in HLA-DRB1 allele frequencies in Han UC patients. The frequencies of DRB1*04, *13*14 alleles were increased in Uyghur UC patients compared with normal controls. The frequency of DRB1*08 was decreased in Uyghur UC patients compared with normal controls. Polymorphism of the HLA-DRB1 gene may contribute to the clinical heterogeneity of UC between Han and Uyghur UC patients in China.

CONCLUSION: HLA-DRB1*04*13*14 and DRB1*08 may contribute to the clinical heterogeneity of UC between Han and Uyghur UC patients.

Clinical features and major histocompatibility complex genes as potential susceptibility factors in pediatric immune thrombocytopenia

BACKGROUND/PURPOSE

Immune thrombocytopenia (ITP) is a heterogeneous autoimmune disorder with diverse response rates to treatments that include corticosteroids, intravenous immunoglobulins (IVIG), and splenectomy. The predisposing causes of this autoimmune disorder, one of which is immunogenetic susceptibility, have not been fully determined. We investigated whether clinical features and human leukocyte antigen (HLA) genotypes influence the occurrence, treatment response, and disease duration of childhood ITP in Taiwan.

METHODS

We performed HLA genotyping of 70 Taiwanese children with ITP and of 70 healthy controls and compared the data. Demographic data were also collected and evaluated.

RESULTS

The frequencies of heterozygous HLA-A11 and the HLA-Cw1 allele were both significantly decreased in the ITP group (p = 0.0160 and p = 0.0089, respectively), whereas the frequency of heterozygous HLA-DQ5 was significantly increased in the ITP group (p = 0.0057). Patients with HLA-DRB1*11 or -DRB1*15 were more likely to respond poorly to corticosteroids than IVIG (p = 0.0446 and p = 0.0008, respectively). In addition, we observed a positive association between HLA-A11 homozygosity and the development of persistent or chronic ITP [odds ratio (OR) = 6.3165, p = 0.0479]. The presence of HLA-DRB1*08 was, however, negatively correlated with the development of persistent or chronic ITP (OR = 0.1729, p = 0.0657). Children with antecedent of preceding illness (API) and with a younger age of onset were more likely to experience a better treatment response and shorter course of ITP.

CONCLUSION

We suggest that API, age of onset, and particular HLA class I and class II alleles, may be involved in and influence the occurrence and disease duration of childhood ITP, as well as responses to different therapeutic approaches.

Inflammatory bowel disease: susceptibility and disease heterogeneity revealed by human leukocyte antigen genotyping

This study aimed to investigate the association between HLA DR/DQ and inflammatory bowel diseases (IBD) in Tunisian patients and to determine the relationship between HLA DR/DQ alleles with the clinical disease patterns. DNA typing of human leukocyte antigen (HLA) genes was performed in 70 ulcerative colitis (UC) patients, 40 Crohn's disease (CD) patients, and 123 healthy controls (HC) using a polymerase chain reaction sequence specific primer technique. Data were analyzed using Cochran-Mantel-Haenszel test and binary logistic regression. Compared with HC, IBD patients showed an increased frequency of the homozygous DRB1*07 genotype. This positive association was maintained when UC and CD were separately compared to HC. In UC patients, DQB1*03:02 was predictive of colonic extension whereas DRB1*13 and DQB1*03:01 were associated limited disease localization (left-sided colitis and proctitis). The DRB1*15 allele increased in patients with extraintestinal manifestations. In CD, female patients showed an increased frequency of DRB1*13, DRB1*15, and DQB1*06 alleles and DRB1*13-DQB1*06 haplotype, whereas a significant increase of DRB1*07, DQB1*02 alleles, and DRB1*07-DQB1*02 haplotype was noted in male patients. These results show a significant association of the homozygous HLA-DRB1*07 genotype with UC and CD and of several HLA DR/DQ alleles and haplotypes with the clinical phenotypes of these diseases in Tunisian patients. Because of limited statistical power, our study findings are subject to further investigation.

Ulcerative colitis complicated with primary biliary cirrhosis

We report a patient who developed ulcerative colitis during the course of primary biliary cirrhosis (PBC). PBC was diagnosed by liver histology when the patient was 31 years old, at which time no symptoms were observed. At 45 years of age, the patient complained of bloody diarrhea and abdominal pain, and she was diagnosed with ulcerative colitis by colonoscopy and histological examination. The patient had HLA-DRB1(*)1502 and (*)0802, which are associated with both diseases. Ulcerative colitis should be considered in the differential diagnosis of bowel disease in patients with PBC. The possible genetic associations between 2 diseases are also discussed.

Influence of HLA-DRB1 alleles on the susceptibility and resistance to multiple sclerosis in Japanese patients with respect to anti-aquaporin 4 antibody status

Background: Epistatic interactions between human leukocyte antigen (HLA)-DRB1 alleles alter multiple sclerosis (MS) risk in Caucasians. Such interactions have never been studied in Asian MS patients.

Objective: To investigate the influence of HLA-DRB1 alleles, including epistatic interactions at this locus, in Japanese MS patients with and without the anti-aquaporin 4 (AQP4) antibody.

Methods: The HLA-DRB1 locus was genotyped in 108 MS patients and 127 healthy controls. MS patients were further classified into two groups according to anti-AQP4 antibody status (27 positive and 81 negative).

Results: HLA-DRB1*09 (adjusted odds ratio (OR) = 0.243, 95% confidence interval (CI) 0.099—0.533) and HLA-DRB1*01 (adjusted OR = 0.327, 95% CI 0.103—0.873) decreased the incidence of anti-AQP4 antibody-negative MS. By contrast, HLA-DRB1*12 increased the risk of anti-AQP4 antibody-positive MS (adjusted OR = 3.691, 95% CI 1.233—10.565). Individuals with HLA-DRB1*09/15 decreased the risk of anti-AQP4 antibody-negative MS (adjusted OR = 0.164, 95% CI 0.026—0.593), while those with HLA-DRB1*12/15 increased the risk of anti-AQP4 antibody-positive MS (adjusted OR = 10.870, 95% CI 2.004—81.752).

Conclusions: The ability of HLA-DRB1*09 to reduce the risk of anti-AQP4 antibody-negative MS may arise from an interaction with HLA-DRB1*15. By contrast, HLA-DRB1*12 increases susceptibility to anti-AQP4 antibody-positive MS, possibly via an interaction with HLA-DRB1*15.