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1.
Proc Natl Acad Sci U S A ; 118(6)2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33542101

RESUMO

T-cell responses to posttranslationally modified self-antigens are associated with many autoimmune disorders. In type 1 diabetes, hybrid insulin peptides (HIPs) are implicated in the T-cell-mediated destruction of insulin-producing ß-cells within pancreatic islets. The natural history of the disease is such that it allows for the study of T-cell reactivity prior to the onset of clinical symptoms. We hypothesized that CD4 T-cell responses to posttranslationally modified islet peptides precedes diabetes onset. In a cohort of genetically at-risk individuals, we measured longitudinal T-cell responses to native insulin and hybrid insulin peptides. Both proinflammatory (interferon-γ) and antiinflammatory (interluekin-10) cytokine responses to HIPs were more robust than those to native peptides, and the ratio of such responses oscillated between pro- and antiinflammatory over time. However, individuals who developed islet autoantibodies or progressed to clinical type 1 diabetes had predominantly inflammatory T-cell responses to HIPs. Additionally, several HIP T-cell responses correlated to worsening measurements of blood glucose, highlighting the relevance of T-cell responses to posttranslationally modified peptides prior to autoimmune disease development.


Assuntos
Autoantígenos/genética , Diabetes Mellitus Tipo 1/genética , Insulina/imunologia , Interferon gama/genética , Peptídeos/genética , Adolescente , Adulto , Autoanticorpos/genética , Autoanticorpos/imunologia , Autoantígenos/imunologia , Autoimunidade/genética , Autoimunidade/imunologia , Linfócitos T CD4-Positivos/imunologia , Criança , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/patologia , Progressão da Doença , Feminino , Humanos , Insulina/genética , Células Secretoras de Insulina/imunologia , Ilhotas Pancreáticas/imunologia , Ilhotas Pancreáticas/patologia , Masculino , Peptídeos/imunologia , Linfócitos T/imunologia , Adulto Jovem
2.
N Engl J Med ; 381(7): 603-613, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31180194

RESUMO

BACKGROUND: Type 1 diabetes is a chronic autoimmune disease that leads to destruction of insulin-producing beta cells and dependence on exogenous insulin for survival. Some interventions have delayed the loss of insulin production in patients with type 1 diabetes, but interventions that might affect clinical progression before diagnosis are needed. METHODS: We conducted a phase 2, randomized, placebo-controlled, double-blind trial of teplizumab (an Fc receptor-nonbinding anti-CD3 monoclonal antibody) involving relatives of patients with type 1 diabetes who did not have diabetes but were at high risk for development of clinical disease. Patients were randomly assigned to a single 14-day course of teplizumab or placebo, and follow-up for progression to clinical type 1 diabetes was performed with the use of oral glucose-tolerance tests at 6-month intervals. RESULTS: A total of 76 participants (55 [72%] of whom were ≤18 years of age) underwent randomization - 44 to the teplizumab group and 32 to the placebo group. The median time to the diagnosis of type 1 diabetes was 48.4 months in the teplizumab group and 24.4 months in the placebo group; the disease was diagnosed in 19 (43%) of the participants who received teplizumab and in 23 (72%) of those who received placebo. The hazard ratio for the diagnosis of type 1 diabetes (teplizumab vs. placebo) was 0.41 (95% confidence interval, 0.22 to 0.78; P = 0.006 by adjusted Cox proportional-hazards model). The annualized rates of diagnosis of diabetes were 14.9% per year in the teplizumab group and 35.9% per year in the placebo group. There were expected adverse events of rash and transient lymphopenia. KLRG1+TIGIT+CD8+ T cells were more common in the teplizumab group than in the placebo group. Among the participants who were HLA-DR3-negative, HLA-DR4-positive, or anti-zinc transporter 8 antibody-negative, fewer participants in the teplizumab group than in the placebo group had diabetes diagnosed. CONCLUSIONS: Teplizumab delayed progression to clinical type 1 diabetes in high-risk participants. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT01030861.).


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Complexo CD3/antagonistas & inibidores , Diabetes Mellitus Tipo 1/prevenção & controle , Adolescente , Adulto , Anticorpos Monoclonais Humanizados/efeitos adversos , Criança , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/imunologia , Progressão da Doença , Método Duplo-Cego , Exantema/induzido quimicamente , Feminino , Teste de Tolerância a Glucose , Antígeno HLA-DR3 , Antígeno HLA-DR4 , Humanos , Contagem de Linfócitos , Linfopenia/induzido quimicamente , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Linfócitos T/imunologia , Adulto Jovem
3.
Diabetologia ; 64(11): 2432-2444, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34338806

RESUMO

AIMS/HYPOTHESIS: Accurate prediction of disease progression in individuals with pre-symptomatic type 1 diabetes has potential to prevent ketoacidosis and accelerate development of disease-modifying therapies. Current tools for predicting risk require multiple blood samples taken during an OGTT. Our aim was to develop and validate a simpler tool based on a single blood draw. METHODS: Models to predict disease progression using a single OGTT time point (0, 30, 60, 90 or 120 min) were developed using TrialNet data collected from relatives with type 1 diabetes and validated in independent populations at high genetic risk of type 1 diabetes (TrialNet, Diabetes Prevention Trial-Type 1, The Environmental Determinants of Diabetes in the Young [1]) and in a general population of Bavarian children who participated in Fr1da. RESULTS: Cox proportional hazards models combining plasma glucose, C-peptide, sex, age, BMI, HbA1c and insulinoma antigen-2 autoantibody status predicted disease progression in all populations. In TrialNet, the AUC for receiver operating characteristic curves for models named M60, M90 and M120, based on sampling at 60, 90 and 120 min, was 0.760, 0.761 and 0.745, respectively. These were not significantly different from the AUC of 0.760 for the gold standard Diabetes Prevention Trial Risk Score, which requires five OGTT blood samples. In TEDDY, where only 120 min blood sampling had been performed, the M120 AUC was 0.865. In Fr1da, the M120 AUC of 0.742 was significantly greater than the M60 AUC of 0.615. CONCLUSIONS/INTERPRETATION: Prediction models based on a single OGTT blood draw accurately predict disease progression from stage 1 or 2 to stage 3 type 1 diabetes. The operational simplicity of M120, its validity across different at-risk populations and the requirement for 120 min sampling to stage type 1 diabetes suggest M120 could be readily applied to decrease the cost and complexity of risk stratification.


Assuntos
Doenças Assintomáticas , Autoanticorpos/sangue , Diabetes Mellitus Tipo 1/diagnóstico , Anticorpos Anti-Insulina/sangue , Proteínas Tirosina Fosfatases Classe 8 Semelhantes a Receptores/imunologia , Transportador 8 de Zinco/imunologia , Adolescente , Área Sob a Curva , Glicemia/metabolismo , Índice de Massa Corporal , Peptídeo C/sangue , Criança , Pré-Escolar , Diabetes Mellitus Tipo 1/sangue , Progressão da Doença , Feminino , Teste de Tolerância a Glucose , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Modelos de Riscos Proporcionais , Curva ROC
4.
Diabetes Obes Metab ; 22(11): 2045-2054, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32573927

RESUMO

AIMS: To test whether a long-acting GLP-1 receptor agonist would improve glucose control in patients with type 1 diabetes (T1D) and to determine whether the presence of residual beta cell function would affect the response. In addition, we sought to determine whether the drug would affect beta cell function. METHODS: We performed a randomized placebo-controlled trial of exenatide extended release (ER) in participants with T1D with and without detectable levels of C-peptide. Seventy-nine participants were randomized to exenatide ER 2 mcg weekly, or placebo, stratified by the presence or absence of detectable C-peptide levels. The primary outcome was the difference in glycated haemoglobin (HbA1c) levels at 24 weeks. Participants were followed for another 6 months off study drug. RESULTS: At week 24, the time of the primary outcome, the least squares (LS) mean HbA1c level was 7.76% (95% confidence interval [CI] 7.42, 8.10) in the exenatide ER group versus 8.0% (95% CI 7.64, 8.35) in the placebo group (P = 0.08). At week 12 the LS mean HbA1c levels were 7.71% (95% CI 7.37, 8.05) in the exenatide ER group versus 8.05% (95% CI 7.7, 8.4) in the placebo group (P = 0.01). The improvement at week 12 was driven mainly by those with detectable levels of C-peptide. Those treated with exenatide ER lost weight at 12 and 24 weeks compared to those treated with placebo (P <0.001 and P = 0.007). The total insulin dose was lower, but not when corrected for body weight, and was not affected by residual insulin production. Adverse events were more frequent with exenatide ER, but hypoglycaemia was not increased. CONCLUSION: Treatment with exenatide ER may have short-term benefits in some individuals with T1D who are overweight or who have detectable levels of C-peptide, but short-term improvements were not sustained.


Assuntos
Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Diabetes Mellitus Tipo 1/tratamento farmacológico , Exenatida , Hemoglobinas Glicadas/análise , Humanos , Hipoglicemiantes/uso terapêutico , Insulina , Peçonhas/uso terapêutico
5.
Diabetologia ; 62(4): 655-664, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30569273

RESUMO

AIMS/HYPOTHESIS: The long-term effects of successful immune therapies for treatment of type 1 diabetes have not been well studied. The Autoimmunity-Blocking Antibody for Tolerance (AbATE) trial evaluated teplizumab, an Fc receptor non-binding humanised anti-CD3 monoclonal antibody in individuals with new-onset type 1 diabetes, and ended in 2011. Clinical drug-treated responders showed an increased frequency of 'partially exhausted' CD8+ T cells. We studied the clinical, immunological and metabolic status of participants after an average follow-up of 7 years. METHODS: Participants with detectable C-peptide at year 2 of AbATE returned for follow-up. C-peptide responses were assessed by 4 h mixed-meal tolerance test. Autoantibodies and HbA1c levels were measured and average daily insulin use was obtained from patient logs. Peripheral blood mononuclear cells were analysed by flow cytometry and cytokine release. RESULTS: Fifty-six per cent of the original participants returned. Three of the original control group who did not return had lost all detectable C-peptide by the end of the 2 year trial. The C-peptide responses to a mixed-meal tolerance test were similar overall in the drug vs control group of participants but were significantly improved, with less loss of C-peptide, in drug-treated responders identified at 1 year. However, the improvements in C-peptide response were not associated with lower HbA1c levels or insulin use. Drug-treated responders showed a significantly increased frequency of programmed cell death protein 1-positive central memory and anergic CD8+ T cells at follow-up. CONCLUSIONS/INTERPRETATION: These findings suggest there is reduced decline in C-peptide and persistent immunological responses up to 7 years after diagnosis of diabetes in individuals who respond to teplizumab. TRIAL REGISTRATION: ClinicalTrials.gov NCT02067923; the protocol is available at www.immunetolerance.org (ITN027AI).


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Adolescente , Adulto , Área Sob a Curva , Autoimunidade , Peptídeo C/sangue , Complexo CD3/imunologia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Criança , Citocinas/metabolismo , Feminino , Seguimentos , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/metabolismo , Ilhotas Pancreáticas/citologia , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto , Indução de Remissão , Resultado do Tratamento , Adulto Jovem
6.
Int J Mol Sci ; 20(16)2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31398795

RESUMO

Islet autoantibody (iAb)-positive individuals have a high risk of progression to type 1 diabetes (T1D), although the rate of progression is highly variable and factors involved in the rate of progression are largely unknown. The ratio of unmethylated/methylated insulin DNA levels (unmethylated INS ratio) has been shown to be higher in participants at high risk of T1D compared to healthy controls. We aimed to evaluate whether an unmethylated INS ratio may be a useful biomarker of beta cell death and rate of progression to T1D. In TrialNet participants who were followed in the Pathway to Prevention Study and progressed to diabetes (n = 57, median age of onset 15.3 years), we measured unmethylated INS ratio and autoantibodies by electrochemiluminescence (ECL) assays (ECL-IAA, ECL-GADA, and ECL-IA2) and radioimmunoassays (RIA) (mIAA, GADA, IA2A, and ZnT8A) longitudinally for 24 months prior to diagnosis. Linear models were used to test the association between unmethylated INS ratio and the age at T1D diagnosis and unmethylated INS ratio and iAb over time. Close to diabetes onset, the unmethylated INS ratio was associated with mIAA (p = 0.003), ECL-IAA (p = 0.002), and IA2A (p = 0.01) levels, but not with GADA, ECL-GADA, ECL-IA2, or ZnT8A levels. No significant associations were found at baseline (24 months prior to T1D diagnosis). Only mIAA levels were significantly associated with an unmethylated INS ratio over time, with a 0.24 change in the ratio for each 0.1 change in mIAA z-score (p = 0.02). Adjusting for a baseline unmethylated INS ratio, an increased rate of change in unmethylated INS ratio from baseline to diabetes onset was associated with a five-year decrease in age at T1D diagnosis (p = 0.04).


Assuntos
Diabetes Mellitus Tipo 1/etiologia , Diabetes Mellitus Tipo 1/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Adolescente , Idade de Início , Autoanticorpos/sangue , Autoanticorpos/imunologia , Biomarcadores , Morte Celular , Criança , Progressão da Doença , Suscetibilidade a Doenças , Feminino , Humanos , Células Secretoras de Insulina/imunologia , Masculino , Metilação , Risco , Adulto Jovem
7.
Diabetologia ; 61(3): 658-670, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29196783

RESUMO

AIMS/HYPOTHESIS: Validated biomarkers are needed to monitor the effects of immune intervention in individuals with type 1 diabetes. Despite their importance, few options exist for monitoring antigen-specific T cells. Previous reports described a combinatorial approach that enables the simultaneous detection and quantification of multiple islet-specific CD8+ T cell populations. Here, we set out to evaluate the performance of a combinatorial HLA-A2 multimer assay in a multi-centre setting. METHODS: The combinatorial HLA-A2 multimer assay was applied in five participating centres using centralised reagents and blinded replicate samples. In preliminary experiments, samples from healthy donors were analysed using recall antigen multimers. In subsequent experiments, samples from healthy donors and individuals with type 1 diabetes were analysed using beta cell antigen and recall antigen multimers. RESULTS: The combinatorial assay was successfully implemented in each participating centre, with CVs between replicate samples that indicated good reproducibility for viral epitopes (mean %CV = 33.8). For beta cell epitopes, the assay was very effective in a single-centre setting (mean %CV = 18.4), but showed sixfold greater variability across multi-centre replicates (mean %CV = 119). In general, beta cell antigen-specific CD8+ T cells were detected more commonly in individuals with type 1 diabetes than in healthy donors. Furthermore, CD8+ T cells recognising HLA-A2-restricted insulin and glutamate decarboxylase epitopes were found to occur at higher frequencies in individuals with type 1 diabetes than in healthy donors. CONCLUSIONS/INTERPRETATION: Our results suggest that, although combinatorial multimer assays are challenging, they can be implemented in multiple laboratories, providing relevant T cell frequency measurements. Assay reproducibility was notably higher in the single-centre setting, suggesting that biomarker analysis of clinical trial samples would be most successful when assays are performed in a single laboratory. Technical improvements, including further standardisation of cytometry platforms, will likely be necessary to reduce assay variability in the multi-centre setting.


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Antígeno HLA-A2/metabolismo , Adulto , Biomarcadores/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Humanos , Insulina/metabolismo , Células Secretoras de Insulina/metabolismo , Masculino , Adulto Jovem
9.
J Autoimmun ; 89: 82-89, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29233566

RESUMO

Autoimmune thyroid disease (AITD), including Hashimoto's thyroiditis (HT) and Graves' disease (GD), is the most common autoimmune disorder in the United States, affecting over 20 million people. At the time of diagnosis, both HD and GD are characterized by the accumulation of B and T lymphocytes in the thyroid gland and production of autoantibodies targeting the thyroid, indicating that a breach in tolerance of autoreactive lymphocytes has occurred. However, few studies have sought to understand the underlying pathogenesis of AITD that ultimately leads to production of autoantibodies and loss of thyroid function. In this study, we analyzed the phenotype of thyroid antigen-reactive B cells in the peripheral blood of recent onset and long standing AITD patients. We found that in recent onset patients thyroid antigen-reactive B cells in blood no longer appear anergic, rather they express CD86, a marker of activation. This likely reflects activation of these cells leading to their production of autoantibodies. Hence, this study reports the early loss of anergy in thyroid antigen-reactive B cells, an event that contributes to development of AITD.


Assuntos
Linfócitos B/imunologia , Doença de Graves/imunologia , Linfócitos T/imunologia , Glândula Tireoide/imunologia , Tireoidite Autoimune/imunologia , Autoanticorpos/imunologia , Antígeno B7-2/metabolismo , Células Cultivadas , Anergia Clonal , Epitopos , Feminino , Humanos , Tolerância Imunológica , Ativação Linfocitária , Masculino
10.
Proc Natl Acad Sci U S A ; 112(14): 4429-34, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25831495

RESUMO

Certain class II MHC (MHCII) alleles in mice and humans confer risk for or protection from type 1 diabetes (T1D). Insulin is a major autoantigen in T1D, but how its peptides are presented to CD4 T cells by MHCII risk alleles has been controversial. In the mouse model of T1D, CD4 T cells respond to insulin B-chain peptide (B:9-23) mimotopes engineered to bind the mouse MHCII molecule, IA(g7), in an unfavorable position or register. Because of the similarities between IA(g7) and human HLA-DQ T1D risk alleles, we examined control and T1D subjects with these risk alleles for CD4 T-cell responses to the same natural B:9-23 peptide and mimotopes. A high proportion of new-onset T1D subjects mounted an inflammatory IFN-γ response much more frequently to one of the mimotope peptides than to the natural peptide. Surprisingly, the control subjects bearing an HLA-DQ risk allele also did. However, these control subjects, especially those with only one HLA-DQ risk allele, very frequently made an IL-10 response, a cytokine associated with regulatory T cells. T1D subjects with established disease also responded to the mimotope rather than the natural B:9-23 peptide in proliferation assays and the proliferating cells were highly enriched in certain T-cell receptor sequences. Our results suggest that the risk of T1D may be related to how an HLA-DQ genotype determines the balance of T-cell inflammatory vs. regulatory responses to insulin, having important implications for the use and monitoring of insulin-specific therapies to prevent diabetes onset.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Inflamação/metabolismo , Insulina/genética , Insulina/metabolismo , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Autoanticorpos/metabolismo , Criança , Citocinas/metabolismo , Feminino , Genótipo , Antígenos HLA-DQ/genética , Humanos , Interferon gama/metabolismo , Interleucina-10/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos NOD , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação , Receptores de Antígenos de Linfócitos T/metabolismo , Homologia de Sequência de Aminoácidos , Adulto Jovem
11.
J Acoust Soc Am ; 143(6): 3418, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29960477

RESUMO

The role of the ossicular joints in the mammalian middle ear is still debated. This work tests the hypothesis that the two synovial joints filter potentially damaging impulsive stimuli by transforming both the peak amplitude and width of these impulses before they reach the cochlea. The three-dimensional (3D) velocity along the ossicular chain in unaltered cadaveric human temporal bones (N = 9), stimulated with acoustic impulses, is measured in the time domain using a Polytec (Waldbronn, Germany) CLV-3D laser Doppler vibrometer. The measurements are repeated after fusing one or both of the ossicular joints with dental cement. Sound transmission is characterized by measuring the amplitude, width, and delay of the impulsive velocity profile as it travels from the eardrum to the cochlea. On average, fusing both ossicular joints causes the stapes velocity amplitude and width to change by a factor of 1.77 (p = 0.0057) and 0.78 (p = 0.011), respectively. Fusing just the incudomalleolar joint has a larger effect on amplitude (a factor of 2.37), while fusing just the incudostapedial joint decreases the stapes velocity on average. The 3D motion of the ossicles is altered by fusing the joints. Finally, the ability of current computational models to predict this behavior is also evaluated.


Assuntos
Estimulação Acústica/métodos , Ossículos da Orelha/fisiologia , Audição , Articulações/fisiologia , Adulto , Idoso , Fenômenos Biomecânicos , Cadáver , Simulação por Computador , Ossículos da Orelha/anatomia & histologia , Feminino , Humanos , Articulações/anatomia & histologia , Fluxometria por Laser-Doppler , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Movimento (Física) , Amplitude de Movimento Articular , Som , Fatores de Tempo , Vibração
12.
Diabetologia ; 60(11): 2139-2147, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28770323

RESUMO

Type 1 diabetes is an autoimmune disease arising from the destruction of pancreatic insulin-producing beta cells. The disease represents a continuum, progressing sequentially at variable rates through identifiable stages prior to the onset of symptoms, through diagnosis and into the critical periods that follow, culminating in a variable depth of beta cell depletion. The ability to identify the very earliest of these presymptomatic stages has provided a setting in which prevention strategies can be trialled, as well as furnishing an unprecedented opportunity to study disease evolution, including intrinsic and extrinsic initiators and drivers. This niche opportunity is occupied by Type 1 Diabetes TrialNet, an international consortium of clinical trial centres that leads the field in intervention and prevention studies, accompanied by deep longitudinal bio-sampling. In this review, we focus on discoveries arising from this unique bioresource, comprising more than 70,000 samples, and outline the processes and science that have led to new biomarkers and mechanistic insights, as well as identifying new challenges and opportunities. We conclude that via integration of clinical trials and mechanistic studies, drawing in clinicians and scientists and developing partnership with industry, TrialNet embodies an enviable and unique working model for understanding a disease that to date has no cure and for designing new therapeutic approaches.


Assuntos
Autoimunidade/imunologia , Diabetes Mellitus Tipo 1/imunologia , Doenças Autoimunes/imunologia , Humanos
13.
Pediatr Diabetes ; 18(2): 136-142, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-26854192

RESUMO

BACKGROUND: Minnesota is home to the largest Somali population in USA, and pediatric diabetes teams are seeing increasing numbers of Somali children with diabetes. OBJECTIVE: To assess the immune basis of diabetes in Somali children in the Twin Cities, Minnesota. METHODS: A total of 31 Somali children ≤19 yr were treated for type 1 diabetes (T1D) at the University of Minnesota Masonic Children's Hospital and Children's Hospitals and Clinics of Minnesota underwent analysis of human leukocyte antigen (HLA) alleles (n = 30) and diabetes autoantibodies [glutamic acid decarboxylase (GAD65), islet antigen 2 (IA-2), zinc transporter 8 (ZnT8); n = 31]. HLA alleles were analyzed in 49 Somalis without diabetes (controls). Anti-transglutaminase autoantibodies (TGA) for celiac disease were also measured. RESULTS: In Somali children with T1D aged 13.5 ± 5 yr (35% female, disease duration 6.5 ± 3.6 yr), the most common HLA allele was DRB1*03:01 (93%, compared with 45% of Somali controls), followed by DRB1*13:02 (27%). There was a relatively low frequency of DR4 (13%). Controls showed a similar pattern. All 31 participants were positive for at least one diabetes autoantibody. Insulin antibodies were positive in 84% (all were on insulin). Excluding insulin antibodies, 23 (74%) subjects tested positive for at least one other diabetes autoantibody; 32% had 1 autoantibody, 32% had 2 autoantibodies, and 10% had 3 autoantibodies. GAD65 autoantibodies were found in 56% of subjects, IA-2 in 29%, and ZnT8 in 26%. Four (13%) were TGA positive. CONCLUSION: The autoantibody and HLA profiles of Somali children with diabetes are consistent with autoimmune diabetes. Their HLA profile is unique with an exceptionally high prevalence of DRB1*03:01 allele and relative paucity of DR4 alleles compared with African Americans with T1D.


Assuntos
Diabetes Mellitus Tipo 1/etnologia , Diabetes Mellitus Tipo 1/genética , Antígeno HLA-DR3/genética , Adolescente , Estudos de Casos e Controles , Criança , Cidades/epidemiologia , Diabetes Mellitus Tipo 1/imunologia , Feminino , Frequência do Gene , Predisposição Genética para Doença , Antígeno HLA-DR4/genética , Humanos , Masculino , Minnesota/epidemiologia , Somália/etnologia , Adulto Jovem
14.
Diabetologia ; 59(6): 1153-61, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27053235

RESUMO

AIMS/HYPOTHESIS: Type 1 diabetes results from T cell mediated destruction of beta cells. We conducted a trial of antithymocyte globulin (ATG) in new-onset type 1 diabetes (the Study of Thymoglobulin to ARrest T1D [START] trial). Our goal was to evaluate the longer-term safety and efficacy of ATG in preserving islet function at 2 years. METHODS: A multicentre, randomised, double-blind, placebo-controlled trial of 6.5 mg/kg ATG (Thymoglobulin) vs placebo in patients with new-onset type 1 diabetes was conducted at seven university medical centres and one Children's Hospital in the USA. The site-stratified randomisation scheme was computer generated at the data coordinating centre using permuted-blocks of size 3 or 6. Eligible participants were between the ages of 12 and 35, and enrolled within 100 days from diagnosis. Subjects were randomised to 6.5 mg/kg ATG (thymoglobulin) vs placebo in a 2:1 ratio. Participants were blinded, and the study design included two sequential patient-care teams: an unblinded study-drug administration team (for the first 8 weeks), and a blinded diabetes management team (for the remainder of the study). Endpoints assessed at 24 months included meal-stimulated C-peptide AUC, safety and immunological responses. RESULTS: Fifty-eight patients were enrolled; at 2 years, 35 assigned to ATG and 16 to placebo completed the study. The pre-specified endpoints were not met. In post hoc analyses, older patients (age 22-35 years) in the ATG group had significantly greater C-peptide AUCs at 24 months than placebo patients. Using complete preservation of baseline C-peptide at 24 months as threshold, nine of 35 ATG-treated participants (vs 2/16 placebo participants) were classified as responders; nine of 11 responders (67%) were older. All participants reported at least one adverse event (AE), with 1,148 events in the 38 ATG participants vs 415 in the 20 placebo participants; a comparable number of infections were noted in the ATG and placebo groups, with no opportunistic infections nor difficulty clearing infections in either group. Circulating T cell subsets depleted by ATG partially reconstituted, but regulatory, naive and central memory subsets remained significantly depleted at 24 months. Beta cell autoantibodies did not change over the 24 months in the ATG-treated or placebo participants. At 12 months, ATG-treated participants had similar humoral immune responses to tetanus and HepA vaccines as placebo-treated participants, and no increased infections. CONCLUSIONS/INTERPRETATION: A brief course of ATG substantially depleted T cell subsets, including regulatory cells, but did not preserve islet function 24 months later in the majority of patients with new-onset type 1 diabetes. ATG preserved C-peptide secretion in older participants, which may warrant further study. TRIAL REGISTRATION: ClinicalTrials.gov NCT00515099 PUBLIC DATA REPOSITORY: START datasets are available in TrialShare www.itntrialshare.org FUNDING: National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH). The trial was conducted by the Immune Tolerance Network (ITN).


Assuntos
Soro Antilinfocitário/uso terapêutico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Adolescente , Adulto , Soro Antilinfocitário/efeitos adversos , Peptídeo C/metabolismo , Criança , Método Duplo-Cego , Humanos , Imunidade Humoral/efeitos dos fármacos , Imunidade Humoral/fisiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Subpopulações de Linfócitos T/metabolismo , Resultado do Tratamento , Adulto Jovem
15.
Curr Diab Rep ; 16(10): 97, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27558810

RESUMO

Type 1 diabetes (T1D) results from the immune-mediated destruction of insulin-producing ß cells located within the pancreatic islets of Langerhans. The autoimmune process leads to a deficiency in insulin production and resultant hyperglycemia requiring lifelong treatment with insulin administration. T1D continues to dramatically increase in incidence, especially in young children. Substantial knowledge surrounding human disease pathogenesis exists, such that T1D is now predictable with the measurement of antibodies in the peripheral blood directed against insulin and other ß cell proteins. With the ability to predict, it naturally follows that T1D should be preventable. As such, over the last two decades, numerous well-controlled clinical trials have been completed attempting to prevent diabetes onset or maintain residual ß cell function after clinical onset, all providing relatively disappointing results. Here, we review the T1D prevention efforts, the current landscape of clinical therapies, and end with a discussion regarding the future outlook for preventing T1D.


Assuntos
Diabetes Mellitus Tipo 1/fisiopatologia , Células Secretoras de Insulina/fisiologia , Ensaios Clínicos Controlados como Assunto , Diabetes Mellitus Tipo 1/imunologia , Diabetes Mellitus Tipo 1/prevenção & controle , Humanos , Insulina/uso terapêutico
17.
Sensors (Basel) ; 15(9): 22798-810, 2015 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-26371007

RESUMO

Fully implantable hearing devices (FIHDs) have been developed as a new technology to overcome the disadvantages of conventional acoustic hearing aids. The implantable microphones currently used in FIHDs, however, have difficulty achieving high sensitivity to environmental sounds, low sensitivity to body noise, and ease of implantation. In general, implantable microphones may be placed under the skin in the temporal bone region of the skull. In this situation, body noise picked up during mastication and touching can be significant, and the layer of skin and hair can both attenuate and distort sounds. The new approach presently proposed is a microphone implanted at the tympanic membrane. This method increases the microphone's sensitivity by utilizing the pinna's directionally dependent sound collection capabilities and the natural resonances of the ear canal. The sensitivity and insertion loss of this microphone were measured in human cadaveric specimens in the 0.1 to 16 kHz frequency range. In addition, the maximum stable gain due to feedback between the trans-tympanic microphone and a round-window-drive transducer, was measured. The results confirmed in situ high-performance capabilities of the proposed trans-tympanic microphone.


Assuntos
Implantes Cocleares , Auxiliares de Audição , Membrana Timpânica/cirurgia , Humanos , Desenho de Prótese , Osso Temporal/cirurgia
18.
J Autoimmun ; 50: 38-41, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24239002

RESUMO

Chromogranin A (ChgA) is a beta cell secretory granule protein and a peptide of ChgA, WE14, was recently identified as a ligand for diabetogenic CD4 T cell clones derived from the NOD mouse. In this study we compared responses of human CD4 T cells from recent onset type 1 diabetic (T1D) and control subjects to WE14 and to an enzymatically modified version of this peptide. T cell responders to antigens were detected in PBMCs from study subjects by an indirect CD4 ELISPOT assay for IFN-γ. T1D patients (n = 27) were recent onset patients within one year of diagnosis, typed for HLA-DQ8. Controls (n = 31) were either 1st degree relatives with no antibodies or from the HLA-matched general population cohort of DAISY/TEDDY. A second cohort of patients (n = 11) and control subjects (n = 11) was tested at lower peptide concentrations. We found that WE14 is recognized by T cells from diabetic subjects vs. controls in a dose dependent manner. Treatment of WE14 with transglutaminase increased reactivity to the peptide in some patients. This work suggests that ChgA is an important target antigen in human T1D subjects and that post-translational modification may play a role in its reactivity and relationship to disease.


Assuntos
Antígenos CD4/imunologia , Cromogranina A/imunologia , Diabetes Mellitus Tipo 1/genética , Peptídeos/imunologia , Adolescente , Adulto , Autoantígenos/genética , Autoantígenos/imunologia , Antígenos CD4/genética , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/patologia , Criança , Cromogranina A/genética , Cromogranina A/farmacologia , Diabetes Mellitus Tipo 1/imunologia , Feminino , Expressão Gênica , Antígenos HLA-DQ/genética , Antígenos HLA-DQ/imunologia , Teste de Histocompatibilidade , Humanos , Masculino , Peptídeos/genética , Peptídeos/farmacologia , Cultura Primária de Células , Transglutaminases/metabolismo , Transglutaminases/farmacologia
19.
Nord J Psychiatry ; 68(3): 213-8, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23750987

RESUMO

BACKGROUND: The Danish Medico-Legal Council provides the court with statements based on available psychiatric assessment reports to assist the law in the use of the Penal Code sections on mentally disordered offenders. AIMS: To analyse the impact of the Council on the courts' choice between punishment and treatment in cases of offenders falling under §69 of the Penal Code, i.e. mentally disordered, although not psychotic offenders. METHODS: In 298 cases of defendants who according to the Medico-Legal Council might fall under §69 the recommendations of the assessment reports, the recommendations of the Council and the final verdicts are compared; and assessment reports from forensic psychiatric centres are compared with those from other psychiatrists. RESULTS: The recommendations of the Medico-Legal Council were often, but not blindly followed by the courts. The probability for the Council to recommend some measure of treatment was about 50% for adult males, and higher for adolescents and for females. In court, however, the two genders as well as adolescents and adults alike all had the same probability, approximately 50%, of being sentenced with treatment instead of punishment. When measured by the final verdict, the Medico-Legal Council is of higher quality than the assessment reports, especially those from outside forensic psychiatry. CONCLUSION: The Council serves as a quality assurance of Danish forensic psychiatric assessments, and the Council's statements are by the court considered to represent the state of the art of these assessments.


Assuntos
Criminosos , Psiquiatria Legal/legislação & jurisprudência , Transtornos Psicóticos/terapia , Punição , Adolescente , Adulto , Dinamarca/epidemiologia , Feminino , Humanos , Modelos Logísticos , Masculino , Transtornos Mentais/epidemiologia , Transtornos Mentais/terapia , Psiquiatria , Transtornos Psicóticos/diagnóstico , Transtornos Psicóticos/epidemiologia , Adulto Jovem
20.
Diabetes ; 73(5): 743-750, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38295386

RESUMO

Hybrid insulin peptides (HIPs) formed through covalent cross-linking of proinsulin fragments to secretory granule peptides are detectable within murine and human islets. The 2.5HIP (C-peptide-chromogranin A [CgA] HIP), recognized by the diabetogenic BDC-2.5 clone, is a major autoantigen in the nonobese diabetic mouse. However, the relevance of this epitope in human disease is currently unclear. A recent study probed T-cell reactivity toward HIPs in patients with type 1 diabetes, documenting responses in one-third of the patients and isolating several HIP-reactive T-cell clones. In this study, we isolated a novel T-cell clone and showed that it responds vigorously to the human equivalent of the 2.5HIP (designated HIP9). Although the responding patient carried the risk-associated DRB1*04:01/DQ8 haplotype, the response was restricted by DRB1*11:03 (DR11). HLA class II tetramer staining revealed higher frequencies of HIP9-reactive T cells in individuals with diabetes than in control participants. Furthermore, in DR11+ participants carrying the DRB4 allele, HIP9-reactive T-cell frequencies were higher than observed frequencies for the immunodominant proinsulin 9-28 epitope. Finally, there was a negative correlation between HIP9-reactive T-cell frequency and age at diagnosis. These results provide direct evidence that this C-peptide-CgA HIP is relevant in human type 1 diabetes and suggest a mechanism by which nonrisk HLA haplotypes may contribute to the development of ß-cell autoimmunity.


Assuntos
Diabetes Mellitus Tipo 1 , Insulina , Humanos , Animais , Camundongos , Linfócitos T , Proinsulina , Peptídeo C , Cromogranina A , Peptídeos , Insulina Regular Humana , Epitopos , Fragmentos de Peptídeos
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