The association of HLA-DP loci with autoimmune diabetes in Chinese

Fifty years of HLA-associated type 1 diabetes risk: history, current knowledge, and future directions

More than 50 years have elapsed since the association of human leukocyte antigens (HLA) with type 1 diabetes (T1D) was first reported. Since then, methods for identification of HLA have progressed from cell based to DNA based, and the number of recognized HLA variants has grown from a few to tens of thousands. Current genotyping methodology allows for exact identification of all HLA-encoding genes in an individual's genome, with statistical analysis methods evolving to digest the enormous amount of data that can be produced at an astonishing rate. The HLA region of the genome has been repeatedly shown to be the most important genetic risk factor for T1D, and the original reported associations have been replicated, refined, and expanded. Even with the remarkable progress through 50 years and over 5,000 reports, a comprehensive understanding of all effects of HLA on T1D remains elusive. This report represents a summary of the field as it evolved and as it stands now, enumerating many past and present challenges, and suggests possible paradigm shifts for moving forward with future studies in hopes of finally understanding all the ways in which HLA influences the pathophysiology of T1D.

Association of human leukocyte antigen (HLA) footprints with the comorbidity of latent autoimmune diabetes in adults (LADA) and hepatitis C virus (HCV) infection: A multicenter cross-sectional study

AIMS

This study aims to investigate the interplay between hepatitis C virus (HCV) infection and major forms of diabetes: type 1 diabetes (T1D), type 2 diabetes (T2D), and latent autoimmune diabetes in adults (LADA).

METHODS

This multicenter study analyzed a cohort of 2699 diabetic and 7344 non-diabetic subjects who visited medical centers in China from 2014 to 2021. T1D, T2D, LADA, and HCV were diagnosed using standard procedures. High-throughput sequencing was conducted to identify genetic footprints of human leukocyte antigen (HLA) alleles and haplotypes at the DRB1, DQA1, and DQB1 loci.

RESULTS

HCV infection was detected in 3 % (23/766) of LADA patients, followed by 1.5 % (15/977) of T2D patients, 1.4 % (13/926) of T1D patients, and 0.5 % (38/7344) of non-diabetic individuals. HCV prevalence was significantly higher in people with diabetes than in non-diabetic individuals (p < 0.01). HLA alleles (DQB1*060101, DQB1*040101) and haplotypes (DRB1*080302-DQA1*010301-DQB1*060101) in LADA patients with HCV revealed higher frequencies than in LADA patients without HCV (adjusted p < 0.03). Furthermore, a higher risk of diabetes complications was found among LADA patients with HCV infection (p < 0.001).

CONCLUSIONS

LADA patients are susceptible to HCV infection, potentially associated with certain HLA alleles/haplotypes. Early diagnosis and treatment of HCV infection among people with diabetes are important for the management of severe complications.

Clinical and HLA genotype analysis of immune checkpoint inhibitor-associated diabetes mellitus: a single-center case series from China

Objective

To investigate the clinical characteristics and HLA genotypes of patients with immune checkpoint inhibitor-associated diabetes mellitus (ICI-DM) in China.

Methods

We enrolled 23 patients with ICI-DM and 51 patients with type 1 diabetes (T1D). Clinical characteristics of the patients were collected. HLA-DRB1, HLA-DQA1, and HLA-DQB1 genotyping was conducted via next-generation sequencing.

Results

The ICI-DM patients had a male predominance (70.6%), a mean body mass index (BMI) of 21.2 ± 3.5 kg/m², and a mean onset of ICI-DM in 5 (IQR, 3-9) cycles after ICI therapy. Most (78.3%) ICI-DM patients were treated with anti-PD-1, 78.3% presented with diabetic ketoacidosis, and all had low C-peptide levels and received multiple insulin injections. Compared to T1D patients, ICI-DM patients were significantly older (57.2 ± 12.4 vs 34.1 ± 15.7 years) and had higher blood glucose but lower HbA1c levels (P<0.05). Only two (8.7%) ICI-DM patients were positive for islet autoantibodies, which was lower than that in T1D patients (66.7%, P<0.001). A total of 59.1% (13/22) of ICI-DM patients were heterozygous for an HLA T1D risk haplotype, and DRB1*0901-DQA1*03-DQB1*0303 (DR9) and DRB1*0405-DQA1*03-DQB1*0401 were the major susceptible haplotypes. Compared to T1D, the susceptible DR3-DQA1*0501-DQB1*0201 (DR3) and DR9 haplotypes were less frequent (17.7% vs 2.3%; P=0.011 and 34.4% vs 15.9%; P=0.025), whereas the protective haplotypes (DRB1*1101-DQA1*05-DQB1*0301 and DRB1*1202-DQA1*0601-DQB1*0301) were more frequent in ICI-DM patients (2.1% vs 13.6%; P=0.006 and 4.2% vs 15.9%; P=0.017). None of the ICI-DM patients had T1D-associated high-risk genotypes DR3/DR3, DR3/DR9, and DR9/DR9. Among the 23 ICI-DM patients, 7 (30.4%) presented with ICI-associated fulminant type 1 diabetes (IFD), and 16 (69.6%) presented with ICI-associated type 1 diabetes (IT1D). Compared to IT1D patients, IFD patients exhibited marked hyperglycemia and low C-peptide and HbA1c levels (P<0.05). Up to 66.7% (4/6) of IFD patients were heterozygous for reported fulminant type 1 diabetes susceptibility HLA haplotypes (DRB1*0405-DQB1*0401 or DRB1*0901-DQB1*0303).

Conclusion

ICI-DM shares similar clinical features with T1D, such as acute onset, poor islet function and insulin dependence. However, the lack of islet autoantibodies, the low frequencies of T1D susceptibility and high frequencies of protective HLA haplotypes indicate that ICI-DM represents a new model distinct from classical T1D.

Critical Amino Acid Variants in HLA-DRB1 and -DQB1 Allotypes in the Development of Classical Type 1 Diabetes and Latent Autoimmune Diabetes in Adults in the Japanese Population

The effects of amino acid variants encoded by the human leukocyte antigen (HLA) class II on the development of classical type 1 diabetes (T1D) and latent autoimmune diabetes in adults (LADA) have not been fully elucidated. We retrospectively investigated the HLA-DRB1 and -DQB1 genes of 72 patients with classical T1D and 102 patients with LADA in the Japanese population and compared the frequencies of HLA-DRB1 and -DQB1 alleles between these patients and the Japanese populations previously reported by another institution. We also performed a blind association analysis with all amino acid positions in classical T1D and LADA, and compared the associations of HLA-DRB1 and -DQB1 amino acid positions in classical T1D and LADA. The frequency of DRß-Phe-13 was significantly higher and those of DRß-Arg-13 and DQß-Gly-70 were significantly lower in patients with classical T1D and LADA than in controls. The frequencies of DRß-His-13 and DQß-Glu-70 were significantly higher in classical T1D patients than in controls. The frequency of DRß-Ser-13 was significantly lower and that of DQß-Arg-70 was significantly higher in LADA patients than in controls. HLA-DRß1 position 13 and HLA-DQß1 position 70 could be critical amino acid positions in the development of classical T1D and LADA.