The direct involvement of the human leukocyte antigen class II DR-DQ genes in type 1 diabetes (T1D) is well established, and these genes display a complex hierarchy of risk effects at the genotype and haplotype levels. We investigated, using data from 38 studies, whether the DR-DQ haplotypes and genotypes show the same relative predispositional effects across populations and ethnic groups. Significant differences in risk within a population were considered, as well as comparisons across populations using the patient/control (P/C) ratio. Within a population, the ratio of the P/C ratios for two different genotypes or haplotypes is a function only of the absolute penetrance values, allowing ranking of risk effects. Categories of consistent predisposing, intermediate ('neutral'), and protective haplotypes were identified and found to correlate with disease prevalence and the marked ethnic differences in DRB1-DQB1 frequencies. Specific effects were identified, for example for predisposing haplotypes, there was a statistically significant and consistent hierarchy for DR4 DQB1*0302s: DRB1*0405 ¼ *0401 ¼ *0402 > *0404 > *0403, with DRB1*0301 DQB1*0200 (DR3) being significantly less predisposing than DRB1*0402 and more than DRB1*0404. The predisposing DRB1*0401 DQB1*0302 haplotype was relatively increased compared with the protective haplotype DRB1*0401 DQB1*0301 in heterozygotes with DR3 compared with heterozygotes with DRB1*0101 DQB1*0501 (DR1). Our results show that metaanalyses and use of the P/C ratio and rankings thereof can be valuable in determining T1D risk factors at the haplotype and amino acid residue levels.
The autoimmune disease process leading to childhood-onset type 1 diabetes appears to start in infancy, and decisions on treatment to prevent initiation of autoimmunity will need to be based on genetic susceptibility alone. We set out to quantify the absolute risk associated with human leukocyte antigen (HLA) DRB1-DQA1-DQB1 class II genotypes and to develop strategies for recruitment into primary prevention trials. HLA class II haplotype- and genotype-specific risks were derived from 753 United Kingdom families from the Bart's-Oxford population-based study of type 1 diabetes and combined with incidence data from the region to calculate the absolute risk of development of diabetes. A hierarchy of susceptibility was established for both HLA class II haplotypes and genotypes, and the sensitivity and specificity of each genotype was established relative to age at disease onset. Highest risk was conferred by the genotype DRB1*03-DQA1*0501-DQB1*0201/DRB1*0401-DQA1*0301-DQB1*0302 (5% absolute risk of diabetes by age 15 yr), although sensitivity was only 22.6%. Combining the six highest risk genotypes conferred similar risk but increased sensitivity to 36.6% and was most sensitive for diagnosis of diabetes before age 5 yr (48.4%), whereas inclusion of 11 genotypes achieved the same sensitivity for diagnosis for ages 10-14 yr. Analysis of genotype-specific risk should form the basis for design of future primary prevention trials in the general population.
OBJECTIVE -HNF-1␣ gene mutations (MODY3) present with marked hyperglycemia in lean young adults and may, therefore, be mistaken for type 1 diabetes, with implications for individual treatment and risk of diabetes in other family members. We examined the prevalence of HNF-1␣ mutations in families with three generations of diabetes identified in a populationbased study of childhood diabetes, representing a subpopulation in which misclassification was likely.RESEARCH DESIGN AND METHODS -In a study population of 1,470 families, 36 families (2.4%) with three affected generations were identified. In the 18 families in whom DNA samples were available, islet autoantibody testing, HLA class II genotyping, and HNF-1␣ sequencing were performed.RESULTS -At least one islet autoantibody was found in 13 of 14 probands, and diabetesassociated HLA class II haplotypes were found in 17 of 18. One proband, who had no islet autoantibodies and was homozygous for the protective HLA haplotype DRB1*02-DQB1*0602, had a novel HNF-1␣ heterozygous nonsense mutation (R54X). This mutation cosegregated with diabetes in the family. The proband, his brother, mother, and maternal grandmother were diagnosed with type 1 diabetes aged 14 -18 years and treated with insulin (0.39 -0.74 units/kg) from diagnosis. The mother has since been successfully transferred to sulfonylurea treatment.CONCLUSIONS -Family history alone is of limited value in identification of individuals with HNF-1␣ mutations, and we propose a stepwise approach that restricts sequencing of the HNF-1␣ gene to those with a family history of diabetes who also test negative for islet autoantibodies. Diabetes Care 26:333-337, 2003T ype 1 diabetes accounts for the vast majority cases of diabetes in young people, but there are other causes of diabetes in this age-group. Mutations in the hepatocyte nuclear factor (HNF) genes 1␣, 1, and 4␣, causing maturityonset diabetes of the young (MODY), typically present in lean individuals with progressive hyperglycemia and osmotic symptoms in adolescence or early adulthood; therefore, they may be misclassified as type 1 diabetes (1). Mutations in the HNF-1␣ gene account for 65% of MODY in U.K. populations (2) and make up the majority of cases that might be mistaken for type 1 diabetes. The distinction between MODY and type 1 diabetes is important because patients with HNF-1␣ mutations are not insulin dependent and are sensitive to sulfonylureas (3). There are also implications for other family members, since the lifetime incidence of type 1 diabetes in the offspring of an affected parent is estimated at 10% (4), whereas risk to the offspring of an affected parent with MODY is 50%.Type 1 diabetes is characterized by islet autoantibodies that are present at diagnosis in up to 97% of children (5) and by a predisposing HLA genotype. A diagnosis of MODY might therefore be suggested by the absence of islet autoantibodies or the coexistence of class II haplotypes known to confer protection against type 1 diabetes. Of 39 patients identified in a Danish popula...
ObjectiveDrug-induced lupus (DIL) is an idiosyncratic side effect of treatments in which symptoms overlap with those of systemic lupus erythematosus (SLE). The spectrum of DIL constantly evolves with that of the pharmacopoeia. Here, we used VigiBase, the WHO global individual case safety reports (ICSRs) database, to identify the main drugs associated with DIL.MethodsWe analysed all ICSRs classified as ‘systemic lupus erythematosus’ according to the Medical Dictionary for Drug Regulatory Activities term (preferred term level) in VigiBase. The drugs considered in the analysis were those not used to treat SLE, with a positive lower end of the 95% credibility interval for the information component (IC025) ≥0, an indicator value for disproportionate Bayesian reporting.ResultsA total of 12 166 DIL ICSRs were identified using VigiBase. From those, 8163 ICSRs reporting on 118 suspected drugs with IC025 ≥0 were extracted. The median age at DIL onset was 49 years and the female to male sex ratio was 4.3. The median delay between start of suspected treatment and DIL occurrence was 172 days. DIL was reported as serious adverse event in 55.4%. Among the 118 suspected drugs, 42 had not been previously reported in association with DIL. The drugs associated with the highest number of DIL cases were infliximab, adalimumab, etanercept, procainamide and hydralazine.ConclusionThis study enables the identification of 118 drugs associated with DIL. The list of suspected drugs may prove useful to physicians when confronted with potential DIL cases.Trial registration numberNCT03480529.
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