Biomedical subjects

Peter Achenbach

Publications and source records attributed to Peter Achenbach.

8 recordsLinked to original sources

PubMed2026

International consensus guidance for general population screening for islet autoantibodies to diagnose early-stage type 1 diabetes: a nominal group technique process.

Type 1 diabetes is an autoimmune disease that targets and destroys insulin-producing beta cells in the pancreatic islets. The incidence of type 1 diabetes is rising globally. At the clinical diagnosis of type 1 diabetes, between 20% and 67% of children and adolescents present with diabetic ketoacidosis (DKA) requiring hospitalisation, and one-third of these require intensive care. Type 1 diabetes can be detected in early stages, prior to the insulin-requiring clinical diagnosis, through screening for islet autoantibodies (IAbs). Identifying individuals with early-stage type 1 diabetes, combined with monitoring of and education on disease progression, prevents DKA and results in a milder clinical onset. This allows for timely insulin initiation in outpatient settings and improved long-term glucose management. Early diagnosis also enables access to novel disease-modifying therapies that can delay the clinical onset of diabetes. In this international consensus, we provide guidance on the principles and practice of implementing general population screening for IAbs to diagnose early-stage type 1 diabetes. We also outline the minimum requirements for establishing effective population screening programmes to diagnose early-stage type 1 diabetes through IAb detection. This consensus statement has been endorsed by the following professional associations: Advanced Technologies & Treatments for Diabetes (ATTD); Association of Diabetes Care and Education Specialists (ADCES); Association Belge Du Diabète; Associazione Medici Diabetologi (AMD); Australian Diabetes Society (ADS); Belgian Diabetes Liga; Breakthrough T1D; Czech Diabetes Society (ČDS); EASD; Finnish Diabetes Association (FDS); Fondazione Italiana Diabete (FID); International Diabetes Federation (IDF)-Europe; International Society of Paediatric and Adolescent Diabetes (ISPAD); Paediatric Endocrinology Nursing Society (PENS); Polish Diabetes Society; Portuguese Diabetes Association (APDP); Sociedade Portuguesa de Diabetologia (SPD); Società Italiana di Diabetologia (SID); Société Francophone du Diabète (SFD) and Type 1 Diabetes Exchange (T1D Exchange).

Consensus report↗

PubMed2006

Combined testing of antibody titer and affinity improves insulin autoantibody measurement: Diabetes Antibody Standardization Program.

The aim of the workshop was to assess whether four laboratories could reproducibly measure insulin autoantibody (IAA) affinity in coded sera from non-diabetic relatives of patients with type 1 diabetes, newly diagnosed patients, and healthy blood donors, and whether combining affinity with autoantibody titer could improve concordance and performance of IAA assays. IAA affinity was measured by competitive binding using constant amounts of Tyr14A [125I] human insulin and increasing quantities of unlabeled human insulin. There was high concordance between laboratories in distinguishing high, moderate, and low affinity IAA, although IAA binding to insulin varied with assay format. Multiple islet autoantibody-positive and patient sera were identified by high affinity IAA regardless of laboratory-designated IAA status. Combining affinity and titer significantly improved sensitivity, specificity, and concordance of IAA measurement. This workshop has demonstrated that different laboratories are able to reproduce IAA affinity results and that considering IAA affinity is likely to improve the diagnostic performance of IAA assays.

Adolescent↗

PubMed2005

Predicting type 1 diabetes.

Predicting type 1 diabetes mellitus (T1DM) is a prerequisite for disease prevention. Prediction is currently performed on three levels, which include the genetic susceptibility for disease, the identification of preclinical T1DM by way of circulating islet autoantibodies, and the use of metabolic tests to stage preclinical disease into late or early prediabetes. Combinations of genetic markers such as HLA genotype, INS genotype, and if and how much family history of T1DM is present can stratify disease risk more than 1000-fold, and can be used for selection of first-degree relatives of patients with T1DM for primary intervention trials. Measurement of autoantibodies in genetically at-risk subjects identifies future cases of T1DM. Further stratification of diabetes risk in autoantibody-positive subjects can be made on the basis of autoantibody characteristics that correspond to the magnitude of the autoantibody response.

Autoantibodies↗

PubMed2005

Diabetes-related antibodies in euglycemic subjects.

Type 1 diabetes mellitus is preceded by autoimmunity against the insulin-producing islet beta cells. Autoantibodies against islet antigens such as insulin, glutamic acid decarboxylase, and the protein tyrosine phosphatase-like molecule IA-2 are found in most patients with type 1 diabetes and are now established markers for the clinical diagnosis and the preclinical phase of this disease. The development of islet autoantibodies and diabetes is influenced by genetic and environmental factors, and the detection and characterization of islet autoantibodies in euglycemic members of affected families identifies some individuals who have a markedly elevated risk for type 1 diabetes. This ability to accurately predict diabetes risk in non-diabetic subjects will prove very useful for targeted recruitment of participants of interventional studies aimed at preventing the progression to type 1 diabetes in subjects at risk.

Autoantibodies↗

PubMed2005

Natural history of type 1 diabetes.

The natural history of autoimmune type 1 diabetes in children is associated with the appearance of islet autoantibodies early in life, which is influenced by genetic and environmental factors. Once islet autoantibodies have developed, the progression to diabetes in antibody-positive individuals is determined by the age of antibody appearance and by the magnitude of the autoimmunity, in turn related to the age of the subject. Characteristics that describe the magnitude of the autoimmunity can stage progression to type 1 diabetes in islet autoantibody-positive subjects regardless of genetic background or age.

Autoantibodies↗

PubMed2004

Mature high-affinity immune responses to (pro)insulin anticipate the autoimmune cascade that leads to type 1 diabetes.

Children at risk for type 1 diabetes can develop early insulin autoantibodies (IAAs). Many, but not all, of these children subsequently develop multiple islet autoantibodies and diabetes. To determine whether disease progression is reflected by autoantibody maturity, IAA affinity was measured by competitive radiobinding assay in first and subsequent IAA-positive samples from children followed from birth in the BABYDIAB cohort. IAA affinity in first positive samples ranged from less than 10(6) l/mol to more than 10(11) l/mol. High affinity was associated with HLA DRB1*04, young age of IAA appearance, and subsequent progression to multiple islet autoantibodies or type 1 diabetes. IAA affinity in multiple antibody-positive children was on average 100-fold higher than in children who remained single IAA positive or became autoantibody negative. All high-affinity IAAs required conservation of human insulin A chain residues 8-13 and were reactive with proinsulin. In contrast, most lower-affinity IAAs were dependent on COOH-terminal B chain residues and did not bind proinsulin. These data are consistent with the concept that type 1 diabetes is associated with sustained early exposure to (pro)insulin in the context of HLA DR4 and show that high-affinity proinsulin-reactive IAAs identify children with the highest diabetes risk.

Amino Acid Sequence↗

PubMed2004

Stratification of type 1 diabetes risk on the basis of islet autoantibody characteristics.

Family history of type 1 diabetes and autoantibodies to the islet antigens insulin (IAA), glutamate decarboxylase (GADA), and the protein tyrosine phosphatase-like protein IA-2 (IA-2A) are strong predictors of type 1 diabetes, but the rate of progression to diabetes in multiple islet autoantibody-positive relatives varies widely. We asked whether detailed characterization of islet autoantibodies that included determination of titer, epitope specificity, and IgG subclass would improve diabetes prediction in a large cohort of autoantibody-positive relatives. The study shows a strong association between risk and high titer, broad antibody responses to IA-2 and insulin. The highest risks were associated with high-titer IA-2A and IAA, IgG2, IgG3, and/or IgG4 subclass of IA-2A and IAA, and antibodies to the IA-2-related molecule IA-2beta. Using models based on these antibody characteristics, autoantibody-positive relatives can be classified into groups with risks of diabetes ranging from 7 to 89% within 5 years.

Adolescent↗

PubMed2002

Spontaneous peripheral T-cell responses to the IA-2beta (phogrin) autoantigen in young nonobese diabetic mice.

Phogrin (IA-2beta), a major autoantigen in type 1 diabetes in man is recognized by peripheral T cells in the nonobese diabetic (NOD) mouse. CD4(+) T-cell clones derived from immunized NOD animals elicit islet destruction in a disease transfer model. Spontaneous proliferative responses to the protein and derived peptide epitopes were detected in peripheral lymph node cells (LNC) of unprimed NOD mice but not BALB/c controls as early as 4 weeks of age at a time point when insulitis in NOD animals is minimal. Responses to irradiated NOD islet cells but not irradiated NOD spleen cells were observed for both male and female NOD animals. Insulin, phogrin and phogrin-peptide 7 (aa 755-777) but not phogrin-peptide 2 (aa 640-659) or tetanus toxin peptide were recognized as antigens. Islet cell-reactive and phogrin peptide 7-specific CD4(+) T-cell lines were generated from splenocytes of unprimed 4-week-old NOD females and shown to secrete Th1-type cytokines. The results show that the phogrin molecule is targeted early in the course of disease in NOD animals at a time when circulating autoantibodies are absent and insulitis is minimal.

Animals↗