Clinical Characteristics And Genetics Of Chinese Patients With Fulminant Type 1 Diabetes

Objective:Fulminant type 1 diabetes mellitus（FT1DM）is the most serious subtype of type 1 diabetes.The purpose of this study is to clarify the clinical characteristics and susceptible genes of FT1DM in China,explore FT1DM from human leukocyte antigen（HLA）genes,and genome wide association study（GWAS）,and establish the foundation for precise intervention of FT1DM.Methods:（1）The clinical data of 458 cases of FT1DM were collected from all parts of the country through the National Clinical Research Center for Metabolic Diseases and the China Federation of Type 1 diabetes,and their clinical characteristics were analyzed,and the differences of clinical characteristics of FT1DM in different subgroups were discussed.（2）The HLA gene of 233 FT1DM patients was sequenced using Illumina sequencing platform,and the loci were genotyped using HLA-HD and PHASE software,and compared with normal control group and classic type 1 diabetes.（3）Using the Asian Screening Array（ASA）gene chip,DNA samples from 226 eligible FT1DM patients and 2236 control groups were genotyped,and GWAS analysis was conducted using bioinformatics software to screen the susceptible locus for FT1DM in Chinese people.Based on GWAS results,single nucleotide polymorphisms（SNPs）were selected to construct a genetic risk score（GRS）system model.Results:（1）A total of 458 FT1DM patients come from 26 provinces across the country,with 228 males and 230 females.The average age was33.9±14.8 years old,ranging from 1 to 76 years old.Among the 420patients with FT1DM,the predisposing factors were described,including121 patients without predisposing factors（28.8%）,99 patients with a history of upper respiratory tract infection（23.6%）,81 patients with a history of abdominal pain or diarrhea（19.3%）,83 patients with pregnancy-related diseases（19.8%）,and 32 patients with drug-related FT1DM（7.6%）.Among FT1DM patients,91.3%of the patients developed diabetes ketoacidosis at the onset of the disease.The positive rate of islet autoantibodies is 21.4%,which could be positive in pregnancy-related FT1DM patients.The clinical characteristics of FT1DM vary among different age groups,and acidosis is more severe in younger age groups.Compared with FT1DM without predisposing factors,FT1DM patients with a history of upper respiratory tract infection having higher Hb A1c levels,body temperature,and lower total cholesterol.Patients with FT1DM who have a history of abdominal pain or diarrhea have lower rates of normal BMI,blood PH,and B-ultrasound/CT of the pancreas,and higher rates of elevated creatine kinase.Patients with FT1DM associated with immune checkpoint inhibitors（ICI）have higher Hb A1c levels;Patients with drug allergy related FT1DM have a higher proportion of elevated transaminases,a higher proportion of elevated blood amylase and less insulin use.Pregnancy related FT1DM patients have higher levels of respiration,total cholesterol,low density lipoprotein cholesterol,and blood chlorine,while their blood potassium and Hb A1c levels are lower.（2）1)We have identified HLA class II susceptible and protective genes in FT1DM patients.The susceptible alleles are DQA1*02:01（OR=2.96 95%CI 1.98-4.44）,DQA1*03:03（OR=2.02,95%CI 1.40-2.90）,DRB1*04:05（OR=1.94 95%CI 1.34-2.81）,DRB1*15:01（OR=1.6395%CI 1.24-2.13）,and DRB1*15:02（OR=2.73 95%CI 1.66-4.50）.The protective alleles are DQA1*01:03（OR=0.26 95%CI 0.15-0.47）,DQA1*01:04（OR=0.48 95%CI 0.29-0.79）,DQA1*05:05（OR=0.3995%CI 0.24-0.64）,and DRB1*08:03（OR=0.28 95%CI 0.16-0.51）.2)We have found HLA-II susceptible haplotypes and protective haplotypes of FT1DM.The haplotype with the highest risk for HLA-DQA1-DQB1 is:DQA1*01:02-DQB1*03:01（OR=21.78 95%CI 4.69-101.14）And the protective haplotypes are:DQA1*01:03-DQB1*06:01（OR=0.27,95%CI0.15-0.49）,DQA1*01:04-DQB1*05:03（OR=0.14,95%CI 0.05～0.45）,DQA1*03:01-DQB1*03:02（OR=0.25,95%CI0.12-0.54）,DQA1*05:05-DQB1*03:01（OR=0.17,95%CI 0.08-0.35）.The haplotype withthehighestriskforHLA-DRB1-DQB1is DRB1*09:01-DQB1*03:01（OR=53.50,95%CI 6.89-415.43）.And the protective haplotypes are DRB1*08:03-DQB1*06:01（OR=0.30,95%CI0.17-0.54）,DRB1*11:01-DQB1*03:01（OR=0.25,95%CI 0.12-0.51）,and DRB1*16:02-DQB1*05:02（OR=0.16,95%CI 0.06-0.44）.The haplotype with the highest risk for HLA-DRB1-DQA1 is:DRB1*15:02-DQA1*01:02（OR=27.82,95%CI 3.34-231.65）;the protective haplotype is DRB1*14:54-DQA1*01:04（OR=0.18,95%CI0.07-0.50）.HLA-DRB1-DQA1-DQB1 protective haplotype is DRB1*11:01-DQA1*05:05-DQB1*03:01（OR=0.25,95%CI 0.10-0.63）.3)We have identified HLA-I susceptible and protective alleles for FT1DM.The susceptible alleles are B*15:02（OR=5.72,95%CI4.31-7.59）and C*08:01（OR=4.76,95%CI 3.70-6.12）.The protective alleles are A*02:07（OR=0.42,95%CI 0.29-0.62）,B*46:01（OR=0.35,95%CI 0.24-0.52）,and C*01:02（OR=0.46,95%CI 0.34-0.62）.4)We have found HLA-I susceptible and protective haplotypes in patients with FT1DM.The haplotype with the highest risk for HLA-A-B is A*30:01-B*15:02（OR=28.87,95%CI 3.47-240.33）;and the protective haplotype is A*02:07-B*46:01（OR=0.35,95%CI 0.22-0.56）.HLA-A-C susceptible haplotype is A*24:02-C*08:01（OR=4.34,95%CI 3.27-19.25）;The two haplotypes with the highest risk for HLA-B-C are B*40:01-C*08:01（OR=53.50,95%CI6.89-415.43）,B*15:02-C*07:02（OR=78.68,95%CI 10.41-594.83）,and the protective haplotypes are B*46:01-C*01:02（OR=0.03,95%CI 0.01-0.10）and B*58:01-C*03:02（OR=0.22,95%CI 0.10-0.49）.5)The DRB1susceptibility allele shared by China and Japan is DRB1*04:05,and the protective allele is DRB1*08:03.DRB1*15:02 is a susceptible allele in Chinese FT1DM patients and a protective allele in Japan.The protected haplotypes shared by China and Japan are DRB1*08:03-DQB1*06:01and DQA1*01:03-DQB1*06:01.（3）Through GWAS analysis,this study identified 313 SNPs significantly associated with FT1DM at a significance level of P<5×10^-5.The vast majority of SNPs are located in the major histocompatibility complex（MHC）region.Seven non-MHC susceptibility sites associated with FT1DM at the genomic level are rs376387624 on PRKRA of chr2q31.2,kgp6334180 on P3H2 of chr3q28,rs77560474 on FAM8A1 of chr6p22.3,kgp17108452 on TBC1D32 of chr6q22.31,rs969476 on CSMD1 of chr8p23.2,rs11149724 on OAT of chr10q26.13,and rs11149724 on LINC00311 of chr16q24.1.A GRS model was constructed using 153 SNPs found based on GWAS analysis.The area under the curve of the subject’s work characteristic curve was 0.76.Conclusion:（1）Inducing factors for FT1DM include viral infection,pregnancy,drug,and food allergies,among which drugs involve drug allergy reactions,immune checkpoint inhibitors,and vaccines.Compared with patients with non predisposing FT1DM,the clinical characteristics of patients with different predisposing FT1DM differ.（2）This study found multiple HLA class I and II susceptibility alleles and haplotypes in Chinese FT1DM patients,which are different from those in Japanese FT1DM patients.（3）In this study,GWAS was used to verify that the genetic susceptibility of FT1DM mostly originates from the MHC region,and seven non-MHC SNPs were found.A GRS model of FT1DM patients was constructed using SNP.