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Trabucchi A, Bombicino SS, Sabljic AV, Marfía JI, Targovnik AM, Iacono RF, Miranda MV, Valdez SN. Development of an immunoassay for the simultaneous detection of GADA and ZnT8A in autoimmune diabetes using a ZnT8/GAD65 chimeric molecule. Front Immunol 2023; 14:1219857. [PMID: 37600804 PMCID: PMC10435855 DOI: 10.3389/fimmu.2023.1219857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/19/2023] [Indexed: 08/22/2023] Open
Abstract
Introduction The combined presence of autoantibodies to the 65 kDa isoform of glutamic acid decarboxylase (GADA) and to the islet-specific cation efflux transporter ZnT8 (ZnT8A) in serum is the best predictive sign of the loss of immune tolerance and the clinical manifestation of autoimmune diabetes mellitus (DM). The screening of GADA and ZnT8A could help to reach to a correct diagnosis and to start an early and adequate treatment. The aim of the study was to develop an immunoassay for the simultaneous detection of these autoantibodies using a chimera molecule that includes the immunodominant regions of ZnT8 and GAD65, expressed by baculovirus-insect cells system. Materials and Methods ZnT8/GAD65 was expressed using the Bac to Bac™ baculovirus expression system. The recombinant chimera was purified by an His6-tag and identified by SDS-PAGE and western blot analysis, and by an indirect ELISA using specific antibodies against ZnT8 and GAD65. A fraction of ZnT8/GAD65 was biotinylated. A bridge ELISA (b-ELISA) was developed using ZnT8/GAD65 immobilized in polystyrene microplates, human sera samples from healthy individuals (n = 51) and diabetic patients (n = 49) were then incubated, and afterwards ZnT8/GAD65-biotin was added. Immune complexes were revealed with Streptavidin-Horseradish Peroxidase. Results were calculated as specific absorbance and expressed as standard deviation scores: SDs. Results ZnT8/GAD65 was efficiently produced, yielding 30 mg/L culture medium, 80% pure. This recombinant chimera retains the immunoreactive conformation of the epitopes that are recognized by their specific antibodies, so it was used for the development of a high sensitivity (75.51%) and specificity (98.04%) b-ELISA for the detection of ZnT8A and/or GADA, in a one-step screening assay. The ROC curves demonstrated that this method had high accuracy to distinguish between samples from healthy individuals and diabetic patients (AUC = 0.9488); the cut-off value was stablished at 2 SDs. Conclusions This immunoassay is useful either to confirm autoimmune diabetes or for detection in routine screening of individuals at risk of autoimmune DM. As DM is a slow progress disease, remaining asymptomatic for a long preclinical period, serological testing is of importance to establish a preventive treatment.
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Affiliation(s)
- Aldana Trabucchi
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Silvina Sonia Bombicino
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Adriana Victoria Sabljic
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Juan Ignacio Marfía
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Alexandra Marisa Targovnik
- Universidad de Buenos (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Biotecnología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Nanobiotecnología (NANOBIOTEC), Buenos Aires, Argentina
| | - Rubén Francisco Iacono
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - María Victoria Miranda
- Universidad de Buenos (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Biotecnología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Nanobiotecnología (NANOBIOTEC), Buenos Aires, Argentina
| | - Silvina Noemí Valdez
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
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Taka AM, Härkönen T, Vähäsalo P, Lempainen J, Veijola R, Ilonen J, Knip M. Heterogeneity in the presentation of clinical type 1 diabetes defined by the level of risk conferred by human leukocyte antigen class II genotypes. Pediatr Diabetes 2022; 23:219-227. [PMID: 34894365 DOI: 10.1111/pedi.13300] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/20/2021] [Accepted: 11/30/2021] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVES The association between human leukocyte antigen (HLA) class II genotypes and susceptibility to type 1 diabetes (T1D) is well established. This study aimed at examining whether there are differences in the presentation of T1D depending on the HLA genotype. RESEARCH DESIGN AND METHODS We divided the study participants (N = 5798) in the Finnish Pediatric Diabetes Register into two groups based on the T1D risk conferred by their HLA genotype (high and moderate-risk genotypes, Group 1 vs. other genotypes, Group 2). We then examined differences in clinical, metabolic, and immunological characteristics. Children included in the study were 0-14-year-old and diagnosed between January 2003 and December 2019. RESULTS Participants in Group 1 were younger at the time of diagnosis (P < 0.001) and had more frequently family members affected by T1D (P < 0.001). Diabetic ketoacidosis (DKA) was more frequent among participants in Group 2 (P = 0.014) who also had a longer duration of symptoms before diagnosis (P < 0.001) and higher hemoglobin A1c (P = 0.001) at diagnosis. The HLA genotype was not, however, directly related to the DKA frequency. The frequency of islet cell antibodies (P < 0.003), insulin autoantibodies (P < 0.001), and islet antigen 2 autoantibodies (P < 0.001) was higher in Group 1 whereas glutamic acid decarboxylase autoantibodies were more frequent (P < 0.001) in Group 2. Group 1 had more participants with multiple autoantibodies (P = 0.027) whereas antibody negativity was more frequent in Group 2 (P = 0.003). CONCLUSIONS These findings indicate disease heterogeneity in relation to both clinical disease presentation and humoral autoimmunity, in particular. This heterogeneity is, at least partly, defined by HLA Class II genotypes.
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Affiliation(s)
- Antti-Mathias Taka
- Pediatric Research Center, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Taina Härkönen
- Pediatric Research Center, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Paula Vähäsalo
- Department of Pediatrics, PEDEGO Research Unit, Medical Research Center, University of Oulu, Oulu, Finland.,Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland
| | - Johanna Lempainen
- Immunogenetics Laboratory, Institute of Biomedicine, University of Turku, Turku, Finland.,Department of Pediatrics, University of Turku and Turku University Hospital, Turku, Finland.,Clinical Microbiology, Turku University Hospital, Turku, Finland
| | - Riitta Veijola
- Department of Pediatrics, PEDEGO Research Unit, Medical Research Center, University of Oulu, Oulu, Finland.,Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland
| | - Jorma Ilonen
- Immunogenetics Laboratory, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Mikael Knip
- Pediatric Research Center, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.,Research Program for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Tampere Center for Child Health Research, Tampere University Hospital, Tampere, Finland
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Sabljic AV, Bombicino SS, Marfía JI, Guerra LL, Steinhardt AP, Faccinetti NI, Iacono RF, Poskus E, Trabucchi A, Valdez SN. Novel Flow Cytometric Immunoassay for Detection of Proinsulin Autoantibodies in Diabetes Mellitus Employing a Recombinant Autoantigen Expressed in E. coli. Front Immunol 2021; 12:648021. [PMID: 33889155 PMCID: PMC8056981 DOI: 10.3389/fimmu.2021.648021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 03/17/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Insulin and proinsulin autoantibodies (IAA/PAA) are usually the first markers to appear in patients with type 1 Diabetes Mellitus (T1DM) and their prevalence ranges from 10 to 60% in the child-adolescent population. The reference method for IAA/PAA detection is the Radioligand Binding Assay (RBA), a highly specific and sensitive technique, but expensive and polluting. The aim of this work was to develop a novel flow cytometric microsphere-based immunoassay (FloCMIA) for PAA detection, employing recombinant human proinsulin (PI), as an alternative method to RBA, less expensive and harmful to the environment. Materials and Methods Human PI was expressed as Thioredoxin fusion protein (TrxPI) in E. coli and a fraction was biotinylated. A double paratope model was used in which samples were incubated with TrxPI-biotin and microspheres adsorbed with TrxPI. The immune complexes were revealed using Streptavidin-Phycoerythrin. The geometric mean of the signals was analyzed, and the results were expressed as Standard Deviation scores (SDs). Sera from 100 normal human control and from 111 type 1 diabetic patients were evaluated by FloCMIA. To correlate the novel assay with RBA, 51 diabetic patients were selected, spanning a wide range of PAA reactivity by RBA. Results The study of ROC curves allowed choosing a cut-off value of 3.0 SDs and the AUC was 0.705, indicating that FloCMIA has fair ability to distinguish between samples from each group. A prevalence of 50% for PAA was obtained in the population of diabetic patients studied. The specificity was 96% and the analytical sensitivity (percentage of patients RBA positive, also positive by FloCMIA) was 69%. There was a substantial agreement between methods (kappa statistic=0.700). Conclusions A novel immunoassay based on flow cytometry that uses easy-to produce recombinant PI was developed. This assay constitutes an innovative and cost-effective alternative to RBA for the determination of PAA in patients' sera. The method developed here, presents good performance and a wide dynamic range together with a small required sample volume. Furthermore, these results make it possible to develop multiplex immunoassays that allow the combined detection of autoantibodies present in T1DM and other related autoimmune diseases.
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Affiliation(s)
- Adriana Victoria Sabljic
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Silvina Sonia Bombicino
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Juan Ignacio Marfía
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Luciano Lucas Guerra
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
| | - Alberto Penas Steinhardt
- Universidad Nacional de Lujan, Departamento de Ciencias Básicas, Laboratorio de Genómica Computacional, Buenos Aires, Argentina
| | - Natalia Inés Faccinetti
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
| | - Rubén Francisco Iacono
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Edgardo Poskus
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Aldana Trabucchi
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
| | - Silvina Noemí Valdez
- Universidad de Buenos Aires (UBA), Facultad de Farmacia y Bioquímica, Departamento de Microbiología, Inmunología, Biotecnología y Genética, Cátedra de Inmunología, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET) Universidad de Buenos Aires, Instituto de Estudios de la Inmunidad Humoral “Prof. Ricardo A. Margni” (IDEHU), Buenos Aires, Argentina
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Knip M, Åkerblom HK, Al Taji E, Becker D, Bruining J, Castano L, Danne T, de Beaufort C, Dosch HM, Dupre J, Fraser WD, Howard N, Ilonen J, Konrad D, Kordonouri O, Krischer JP, Lawson ML, Ludvigsson J, Madacsy L, Mahon JL, Ormisson A, Palmer JP, Pozzilli P, Savilahti E, Serrano-Rios M, Songini M, Taback S, Vaarala O, White NH, Virtanen SM, Wasikowa R. Effect of Hydrolyzed Infant Formula vs Conventional Formula on Risk of Type 1 Diabetes: The TRIGR Randomized Clinical Trial. JAMA 2018; 319:38-48. [PMID: 29297078 PMCID: PMC5833549 DOI: 10.1001/jama.2017.19826] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
IMPORTANCE Early exposure to complex dietary proteins may increase the risk of type 1 diabetes in children with genetic disease susceptibility. There are no intact proteins in extensively hydrolyzed formulas. OBJECTIVE To test the hypothesis that weaning to an extensively hydrolyzed formula decreases the cumulative incidence of type 1 diabetes in young children. DESIGN, SETTING, AND PARTICIPANTS An international double-blind randomized clinical trial of 2159 infants with human leukocyte antigen-conferred disease susceptibility and a first-degree relative with type 1 diabetes recruited from May 2002 to January 2007 in 78 study centers in 15 countries; 1081 were randomized to be weaned to the extensively hydrolyzed casein formula and 1078 to a conventional formula. The follow-up of the participants ended on February 28, 2017. INTERVENTIONS The participants received either a casein hydrolysate or a conventional adapted cow's milk formula supplemented with 20% of the casein hydrolysate. The minimum duration of study formula exposure was 60 days by 6 to 8 months of age. MAIN OUTCOMES AND MEASURES Primary outcome was type 1 diabetes diagnosed according to World Health Organization criteria. Secondary outcomes included age at diabetes diagnosis and safety (adverse events). RESULTS Among 2159 newborn infants (1021 female [47.3%]) who were randomized, 1744 (80.8%) completed the trial. The participants were observed for a median of 11.5 years (quartile [Q] 1-Q3, 10.2-12.8). The absolute risk of type 1 diabetes was 8.4% among those randomized to the casein hydrolysate (n = 91) vs 7.6% among those randomized to the conventional formula (n = 82) (difference, 0.8% [95% CI, -1.6% to 3.2%]). The hazard ratio for type 1 diabetes adjusted for human leukocyte antigen risk group, duration of breastfeeding, duration of study formula consumption, sex, and region while treating study center as a random effect was 1.1 (95% CI, 0.8 to 1.5; P = .46). The median age at diagnosis of type 1 diabetes was similar in the 2 groups (6.0 years [Q1-Q3, 3.1-8.9] vs 5.8 years [Q1-Q3, 2.6-9.1]; difference, 0.2 years [95% CI, -0.9 to 1.2]). Upper respiratory infections were the most common adverse event reported (frequency, 0.48 events/year in the hydrolysate group and 0.50 events/year in the control group). CONCLUSIONS AND RELEVANCE Among infants at risk for type 1 diabetes, weaning to a hydrolyzed formula compared with a conventional formula did not reduce the cumulative incidence of type 1 diabetes after median follow-up for 11.5 years. These findings do not support a need to revise the dietary recommendations for infants at risk for type 1 diabetes. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00179777.
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Affiliation(s)
| | - Mikael Knip
- University of Helsinki, Helsinki, Finland
- Helsinki University Hospital, Helsinki, Finland
| | | | - Eva Al Taji
- Charles University, 3rd Faculty of Medicine, Prague, Czech Republic
| | | | - Jan Bruining
- Sophia Children's Hospital, Rotterdam, the Netherlands
| | - Luis Castano
- Cruces University Hospital-UPV/EHU-CIBERDEM/CIBERER, Barakaldo, Spain
| | - Thomas Danne
- Kinder-und Jugendkrankenhaus Auf Der Bult, Hannover, Germany
| | | | | | - John Dupre
- University of Western Ontario, London, Ontario, Canada
| | | | | | - Jorma Ilonen
- University of Turku and Turku University Hospital, Turku, Finland
| | - Daniel Konrad
- University Children's Hospital Zürich, Zürich, Switzerland
| | - Olga Kordonouri
- Kinder-und Jugendkrankenhaus Auf Der Bult, Hannover, Germany
| | | | | | | | | | | | | | | | | | | | - Manuel Serrano-Rios
- Spanish Biomedical Research Centre in Diabetes and Associated Metabolic Disorders (CIBERDEM), Madrid, Spain
| | - Marco Songini
- St Michelle Hospital /Azienda Ospedaliera Brotzu-Diabetes Unit, Cagliari, Italy
| | | | - Outi Vaarala
- University of Helsinki, Helsinki, Finland
- Respiratory, Inflammation and Autoimmunity, Innovative Medicine, AstraZeneca, Gothenburg, Sweden
| | - Neil H White
- Washington University School of Medicine, St Louis, Missouri
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Guerra LL, Faccinetti NI, Trabucchi A, Rovitto BD, Sabljic AV, Poskus E, Iacono RF, Valdez SN. Novel prokaryotic expression of thioredoxin-fused insulinoma associated protein tyrosine phosphatase 2 (IA-2), its characterization and immunodiagnostic application. BMC Biotechnol 2016; 16:84. [PMID: 27881117 PMCID: PMC5122161 DOI: 10.1186/s12896-016-0309-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 10/21/2016] [Indexed: 11/11/2022] Open
Abstract
Background The insulinoma associated protein tyrosine phosphatase 2 (IA-2) is one of the immunodominant autoantigens involved in the autoimmune attack to the beta-cell in Type 1 Diabetes Mellitus. In this work we have developed a complete and original process for the production and recovery of the properly folded intracellular domain of IA-2 fused to thioredoxin (TrxIA-2ic) in Escherichia coli GI698 and GI724 strains. We have also carried out the biochemical and immunochemical characterization of TrxIA-2icand design variants of non-radiometric immunoassays for the efficient detection of IA-2 autoantibodies (IA-2A). Results The main findings can be summarized in the following statements: i) TrxIA-2ic expression after 3 h of induction on GI724 strain yielded ≈ 10 mg of highly pure TrxIA-2ic/L of culture medium by a single step purification by affinity chromatography, ii) the molecular weight of TrxIA-2ic (55,358 Da) could be estimated by SDS-PAGE, size exclusion chromatography and mass spectrometry, iii) TrxIA-2ic was properly identified by western blot and mass spectrometric analysis of proteolytic digestions (63.25 % total coverage), iv) excellent immunochemical behavior of properly folded full TrxIA-2ic was legitimized by inhibition or displacement of [35S]IA-2 binding from IA-2A present in Argentinian Type 1 Diabetic patients, v) great stability over time was found under proper storage conditions and vi) low cost and environmentally harmless ELISA methods for IA-2A assessment were developed, with colorimetric or chemiluminescent detection. Conclusions E. coli GI724 strain emerged as a handy source of recombinant IA-2ic, achieving high levels of expression as a thioredoxin fusion protein, adequately validated and applicable to the development of innovative and cost-effective immunoassays for IA-2A detection in most laboratories. Electronic supplementary material The online version of this article (doi:10.1186/s12896-016-0309-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Luciano Lucas Guerra
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Natalia Inés Faccinetti
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Aldana Trabucchi
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Bruno David Rovitto
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Adriana Victoria Sabljic
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Edgardo Poskus
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Ruben Francisco Iacono
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina
| | - Silvina Noemí Valdez
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Estudios de la Inmunidad Humoral "Prof. Ricardo A. Margni" (IDEHU), Facultad de Farmacia y Bioquímica, Buenos Aires, Argentina.
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Guerra LL, Trabucchi A, Faccinetti NI, Iacono RF, Ureta DB, Poskus E, Valdez SN. Flow cytometric microsphere-based immunoassay as a novel non-radiometric method for the detection of glutamic acid decarboxylase autoantibodies in type 1 diabetes mellitus. Analyst 2015; 139:3017-25. [PMID: 24783226 DOI: 10.1039/c3an02243a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first measurable sign of arising autoimmunity in type 1 diabetes mellitus is the detection of autoantibodies against beta-cell antigens, such as glutamic acid decarboxylase (GAD65). GAD65 autoantibodies (GADA) are usually measured by the Radioligand Binding Assay (RBA). The aim of this work was to develop protocols of flow cytometric microsphere-based immunoassays (FloCMIA) which involved glutamic acid decarboxylase fused to thioredoxin (TrxGAD65) adsorbed on polystyrene microspheres. Detection of bound GADA was accomplished by the use of anti-human IgG-Alexa Fluor 488 (protocol A), anti-human IgG-biotin and streptavidin-dichlorotriazinyl aminofluorescein (DTAF) (protocol B) or TrxGAD65-biotin and streptavidin-DTAF (protocol C). Serum samples obtained from 46 patients assayed for routine autoantibodies at Servicios Tecnológicos de Alto Nivel (STAN-CONICET) were analyzed by RBA, ELISA and three alternative FloCMIA designs. Protocol C exhibited the highest specificity (97.8%) and sensitivity (97.4%) and a wide dynamic range (1.00-134.40 SDs). Samples obtained from 40 new-onset diabetic patients were also analyzed to further evaluate the performance of protocol C. The latter protocol showed a sensitivity of 58.6% and a prevalence of 47.5%. Two patients resulted positive only by FloCMIA protocol C and its SDs were higher than those of RBA and ELISA, showing a significantly wide dynamic range. In conclusion, FloCMIA proved to be highly sensitive and specific, requiring a low sample volume; it is environmentally adequate, innovative and represents a cost-effective alternative to traditional GADA determination by RBA and/or ELISA, making it applicable to most medium-complexity laboratories.
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Affiliation(s)
- Luciano L Guerra
- Chair of Immunology, School of Pharmacy and Biochemistry, University of Buenos Aires (UBA), Humoral Immunity Institute Prof. Ricardo A. Margni (IDEHU), National Research Council (CONICET-UBA), Junín 956, C1113AAD, Buenos Aires, Argentina.
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Knip M, Åkerblom HK, Becker D, Dosch HM, Dupre J, Fraser W, Howard N, Ilonen J, Krischer JP, Kordonouri O, Lawson ML, Palmer JP, Savilahti E, Vaarala O, Virtanen SM. Hydrolyzed infant formula and early β-cell autoimmunity: a randomized clinical trial. JAMA 2014; 311:2279-87. [PMID: 24915259 PMCID: PMC4225544 DOI: 10.1001/jama.2014.5610] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
IMPORTANCE The disease process leading to clinical type 1 diabetes often starts during the first years of life. Early exposure to complex dietary proteins may increase the risk of β-cell autoimmunity in children at genetic risk for type 1 diabetes. Extensively hydrolyzed formulas do not contain intact proteins. OBJECTIVE To test the hypothesis that weaning to an extensively hydrolyzed formula decreases the cumulative incidence of diabetes-associated autoantibodies in young children. DESIGN, SETTING, AND PARTICIPANTS A double-blind randomized clinical trial of 2159 infants with HLA-conferred disease susceptibility and a first-degree relative with type 1 diabetes recruited from May 2002 to January 2007 in 78 study centers in 15 countries; 1078 were randomized to be weaned to the extensively hydrolyzed casein formula and 1081 were randomized to be weaned to a conventional cows' milk-based formula. The participants were observed to April 16, 2013. INTERVENTIONS The participants received either a casein hydrolysate or a conventional cows' milk formula supplemented with 20% of the casein hydrolysate. MAIN OUTCOMES AND MEASURES: Primary outcome was positivity for at least 2 diabetes-associated autoantibodies out of 4 analyzed. Autoantibodies to insulin, glutamic acid decarboxylase, and the insulinoma-associated-2 (IA-2) molecule were analyzed using radiobinding assays and islet cell antibodies with immunofluorescence during a median observation period of 7.0 years (mean, 6.3 years). RESULTS The absolute risk of positivity for 2 or more islet autoantibodies was 13.4% among those randomized to the casein hydrolysate formula (n = 139) vs 11.4% among those randomized to the conventional formula (n = 117). The unadjusted hazard ratio for positivity for 2 or more autoantibodies among those randomized to be weaned to the casein hydrolysate was 1.21 (95% CI, 0.94-1.54), compared with those randomized to the conventional formula, while the hazard ratio adjusted for HLA risk, duration of breastfeeding, vitamin D use, study formula duration and consumption, and region was 1.23 (95% CI, 0.96-1.58). There were no clinically significant differences in the rate of reported adverse events between the 2 groups. CONCLUSIONS AND RELEVANCE Among infants at risk for type 1 diabetes, the use of a hydrolyzed formula, when compared with a conventional formula, did not reduce the incidence of diabetes-associated autoantibodies after 7 years. These findings do not support a benefit from hydrolyzed formula. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00179777.
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Affiliation(s)
| | | | | | | | - John Dupre
- University of Western Ontario, London, Canada
| | | | | | | | | | - Olga Kordonouri
- Kinder- und Jugendkrankenhaus AUF DER BULT, Hannover, Germany
| | | | | | | | - Outi Vaarala
- National Institute for Health and Welfare, Helsinki, Finland
| | - Suvi M Virtanen
- National Institute for Health and Welfare, Helsinki, Finland
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Marrero D, Pan Q, Barrett-Connor E, de Groot M, Zhang P, Percy C, Florez H, Ackermann R, Montez M, Rubin RR. Impact of diagnosis of diabetes on health-related quality of life among high risk individuals: the Diabetes Prevention Program outcomes study. Qual Life Res 2013; 23:75-88. [PMID: 23709097 DOI: 10.1007/s11136-013-0436-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/14/2013] [Indexed: 01/24/2023]
Abstract
PURPOSE The purpose of this study is to assess if diagnosis of type 2 diabetes affected health-related quality of life (HRQoL) among participants in the Diabetes Prevention Program/Diabetes Prevention Program Outcome Study and changes with treatment or diabetes duration. METHODS 3,210 participants with pre-diabetes were randomized to metformin (MET), intensive lifestyle intervention (ILS), or placebo (PLB). HRQoL was assessed using the SF-36 including: (1) 8 SF-36 subscales; (2) the physical component (PCS) and mental component summary (MCS) scores; and (3) the SF-6D. The sample was categorized by diabetes free versus diagnosed. For diagnosed subgroup, mean scores in the diabetes-free period, at 6 months, 2, 4 and 6 years post-diagnosis, were compared. RESULTS PCS and SF-6D scores declined in all participants in all treatment arms (P < .001). MCS scores did not change significantly in any treatment arm regardless of diagnosis. ILS participants reported a greater decrease in PCS scores at 6 months post-diagnosis (P < .001) and a more rapid decline immediately post-diagnosis in SF-6D scores (P = .003) than the MET or PLB arms. ILS participants reported a significant decrease in the social functioning subscale at 6 months (P < .001) and two years (P < .001) post-diagnosis. CONCLUSIONS Participants reported a decline in measures of overall health state (SF-6D) and overall physical HRQoL, whether or not they were diagnosed with diabetes during the study. There was no change in overall mental HRQoL. Participants in the ILS arm with diabetes reported a more significant decline in some HRQoL measures than those in the MET and PLB arms that developed diabetes.
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Affiliation(s)
- D Marrero
- Indiana University School of Medicine, Indianapolis, IN, USA,
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Patelarou E, Girvalaki C, Brokalaki H, Patelarou A, Androulaki Z, Vardavas C. Current evidence on the associations of breastfeeding, infant formula, and cow's milk introduction with type 1 diabetes mellitus: a systematic review. Nutr Rev 2012; 70:509-19. [PMID: 22946851 DOI: 10.1111/j.1753-4887.2012.00513.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Current evidence provides contradictory results in regards to the associations of breastfeeding or early introduction of cow's milk and formula with the development of type 1 diabetes (T1D). The aim of this systematic review was to evaluate the type of feeding, duration of breastfeeding, time of introduction of formula or cow's milk, and the potential impact on developing T1D. The literature search was conducted based on the standards outlined in the MOOSE Guidelines for Meta-Analyses and Systematic Reviews of Observational Studies and yielded a total of 161 studies, 28 of which were included in this review. Twenty seven of the included studies were case-control and one was a prospective cohort study. Eight of the studies indicated breastfeeding has a protective role against the development of T1D. Seven additional studies emphasized that a short period or absence of breastfeeding could be a risk factor for T1D development. The results of this systematic review indicate a short duration and/or a lack of breastfeeding may constitute a risk factor for the development of T1D later in life.
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Affiliation(s)
- Evridiki Patelarou
- University Hospital of Heraklion, Department of Social Medicine, University of Crete, Greece.
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10
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Abstract
Type 1 diabetes is an autoimmune disease that gradually destructs insulin-producing beta cells. Over the years, clinicians' knowledge regarding the immunopathogenesis of this disease has greatly increased. Immunotherapies that can change the course of immune-mediated destruction and preserve and possibly regenerate the pancreatic beta cells seem to be promising in preclinical trials but so far have been unsuccessful in human studies. This article reviews the important immune interventions for type 1 diabetes that have been tried so far targeting the different stages of disease development and provides an insight into what the future might hold.
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Affiliation(s)
- Smita Gupta
- Diabetes and Endocrinology Consultants, 8435 Clearvista Place, Suite 101 Indianapolis, IN 46256, USA.
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11
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Arkkola T, Kautiainen S, Takkinen HM, Kenward MG, Nevalainen J, Uusitalo U, Simell O, Ilonen J, Knip M, Veijola R, Virtanen SM. Relationship of maternal weight status and weight gain rate during pregnancy to the development of advanced beta cell autoimmunity in the offspring: a prospective birth cohort study. Pediatr Diabetes 2011; 12:478-84. [PMID: 21129139 DOI: 10.1111/j.1399-5448.2010.00703.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE This study set out to examine how maternal initial body mass index (BMI) and weight gain during pregnancy associate with advanced beta cell autoimmunity in the offspring. SUBJECTS A population-based birth cohort of 4093 children with increased human leukocyte antigen (HLA)-conferred susceptibility to type 1 diabetes (T1D) and their mothers were recruited between 1997 and 2002 in two university hospital regions in Finland. METHODS The children were monitored for T1D-associated autoantibodies at 3- to 12-month intervals. Advanced beta cell autoimmunity was defined as repeated positivity for islet cell antibodies and at least one of the other three autoantibodies (antibodies to insulin, glutamate decarboxylase and islet antigen 2). Mothers were asked to record the results of the weight measurements during their first and last visits to the antenatal clinic. The initial BMI and weight gain rate were calculated for each woman. RESULTS Altogether, 175 children developed advanced beta cell autoimmunity or T1D during the follow-up. Maternal BMI before pregnancy or weight gain during pregnancy was not associated with the end-point. Maternal vocational education was associated with child's smaller risk of developing advanced beta cell autoimmunity.
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Affiliation(s)
- Tuula Arkkola
- Department of Pediatrics, University of Oulu, FI-90014 Oulu, Finland.
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Knip M, Virtanen SM, Seppä K, Ilonen J, Savilahti E, Vaarala O, Reunanen A, Teramo K, Hämäläinen AM, Paronen J, Dosch HM, Hakulinen T, Akerblom HK. Dietary intervention in infancy and later signs of beta-cell autoimmunity. N Engl J Med 2010; 363:1900-8. [PMID: 21067382 PMCID: PMC4242902 DOI: 10.1056/nejmoa1004809] [Citation(s) in RCA: 224] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Early exposure to complex dietary proteins may increase the risk of beta-cell autoimmunity and type 1 diabetes in children with genetic susceptibility. We tested the hypothesis that supplementing breast milk with highly hydrolyzed milk formula would decrease the cumulative incidence of diabetes-associated autoantibodies in such children. METHODS In this double-blind, randomized trial, we assigned 230 infants with HLA-conferred susceptibility to type 1 diabetes and at least one family member with type 1 diabetes to receive either a casein hydrolysate formula or a conventional, cow's-milk-based formula (control) whenever breast milk was not available during the first 6 to 8 months of life. Autoantibodies to insulin, glutamic acid decarboxylase (GAD), the insulinoma-associated 2 molecule (IA-2), and zinc transporter 8 were analyzed with the use of radiobinding assays, and islet-cell antibodies were analyzed with the use of immunofluorescence, during a median observation period of 10 years (mean, 7.5). The children were monitored for incident type 1 diabetes until they were 10 years of age. RESULTS The unadjusted hazard ratio for positivity for one or more autoantibodies in the casein hydrolysate group, as compared with the control group, was 0.54 (95% confidence interval [CI], 0.29 to 0.95), and the hazard ratio adjusted for an observed difference in the duration of exposure to the study formula was 0.51 (95% CI, 0.28 to 0.91). The unadjusted hazard ratio for positivity for two or more autoantibodies was 0.52 (95% CI, 0.21 to 1.17), and the adjusted hazard ratio was 0.47 (95% CI, 0.19 to 1.07). The rate of reported adverse events was similar in the two groups. CONCLUSIONS Dietary intervention during infancy appears to have a long-lasting effect on markers of beta-cell autoimmunity--markers that may reflect an autoimmune process leading to type 1 diabetes. (ClinicalTrials.gov number, NCT00570102.).
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Affiliation(s)
- Mikael Knip
- Hospital for Children and Adolescents, University of Helsinki and Helsinki University Central Hospital, Helsinki, Finland.
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13
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Knip M, Korhonen S, Kulmala P, Veijola R, Reunanen A, Raitakari OT, Viikari J, Akerblom HK. Prediction of type 1 diabetes in the general population. Diabetes Care 2010; 33:1206-12. [PMID: 20508230 PMCID: PMC2875424 DOI: 10.2337/dc09-1040] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To evaluate the utility of GAD antibodies (GADAs) and islet antigen-2 antibodies (IA-2As) in prediction of type 1 diabetes over 27 years in the general population and to assess the 6-year rates of seroconversion. RESEARCH DESIGN AND METHODS A total of 3,475 nondiabetic subjects aged 3-18 years were sampled in 1980, and 2,375 subjects (68.3%) were resampled in 1986. All subjects were observed for development of diabetes to the end of 2007. GADAs and IA-2As were analyzed in all samples obtained in 1980 and 1986. RESULTS A total of 34 individuals (1.0%; 9 developed diabetes) initially had GADAs and 22 (0.6%; 9 developed diabetes) IA-2As. Seven subjects (0.2%) tested positive for both autoantibodies. The positive seroconversion rate over 6 years was 0.4% for GADAs and 0.2% for IA-2As, while the inverse seroconversion rates were 33 and 57%, respectively. Eighteen subjects (0.5%) developed type 1 diabetes after a median pre-diabetic period of 8.6 years (range 0.9-20.3). Initial positivity for GADAs and/or IA-2As had a sensitivity of 61% (95% CI 36-83) for type 1 diabetes. Combined positivity for GADAs and IA-2As had both a specificity and a positive predictive value of 100% (95% CI 59-100). CONCLUSIONS One-time screening for GADAs and IA-2As in the general childhood population in Finland would identify approximately 60% of those individuals who will develop type 1 diabetes over the next 27 years, and those subjects who have both autoantibodies carry an extremely high risk for diabetes. Both positive and inverse seroconversions do occur over time reflecting a dynamic process of beta-cell autoimmunity.
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Affiliation(s)
- Mikael Knip
- Hospital for Children and Adolescents, University of Helsinki, Helsinki, Finland.
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15
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Collins CD, Purohit S, Podolsky RH, Zhao HS, Schatz D, Eckenrode SE, Yang P, Hopkins D, Muir A, Hoffman M, McIndoe RA, Rewers M, She JX. The application of genomic and proteomic technologies in predictive, preventive and personalized medicine. Vascul Pharmacol 2006; 45:258-67. [PMID: 17030152 DOI: 10.1016/j.vph.2006.08.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2006] [Revised: 08/05/2006] [Accepted: 08/05/2006] [Indexed: 11/17/2022]
Abstract
The long asymptomatic period before the onset of chronic diseases offers good opportunities for disease prevention. Indeed, many chronic diseases may be preventable by avoiding those factors that trigger the disease process (primary prevention) or by use of therapy that modulates the disease process before the onset of clinical symptoms (secondary prevention). Accurate prediction is vital for disease prevention so that therapy can be given to those individuals who are most likely to develop the disease. The utility of predictive markers is dependent on three parameters, which must be carefully assessed: sensitivity, specificity and positive predictive value. Specificity is important if a biomarker is to be used to identify individuals either for counseling or for preventive therapy. However, a reciprocal relationship exists between sensitivity and specificity. Thus, successful biomarkers will be highly specific without sacrificing sensitivity. Unfortunately, biomarkers with ideal specificity and sensitivity are difficult to find for many diseases. One potential solution is to use the combinatorial power of a large number of biomarkers, each of which alone may not offer satisfactory specificity and sensitivity. Recent technological advances in genetics, genomics, proteomics, and bioinformatics offer a great opportunity for biomarker discovery. The newly identified biomarkers have the potential to bring increased accuracy in disease diagnosis and classification, as well as therapeutic monitoring. In this review, we will use type 1 diabetes (T1D) as an example, when appropriate, to discuss pertinent issues related to high throughput biomarker discovery.
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Affiliation(s)
- C D Collins
- Center for Biotechnology and Genomic Medicine, Medical College of Georgia, 1120 15th Street, CA4124, Augusta, GA 30912-2400, United States
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16
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Virtanen SM, Kenward MG, Erkkola M, Kautiainen S, Kronberg-Kippilä C, Hakulinen T, Ahonen S, Uusitalo L, Niinistö S, Veijola R, Simell O, Ilonen J, Knip M. Age at introduction of new foods and advanced beta cell autoimmunity in young children with HLA-conferred susceptibility to type 1 diabetes. Diabetologia 2006; 49:1512-21. [PMID: 16596359 DOI: 10.1007/s00125-006-0236-1] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2005] [Accepted: 02/14/2006] [Indexed: 12/24/2022]
Abstract
AIMS/HYPOTHESIS Evidence for the role of infant feeding in the development of beta cell autoimmunity is inconsistent. We set out to study the effects of breastfeeding and of age at introduction of supplementary foods on the development of beta cell autoimmunity. SUBJECTS AND METHODS A prospective birth cohort of 3,565 infants with HLA-DQB1-conferred susceptibility to type 1 diabetes was recruited between 1996 and 2001 from two university hospital areas in Finland. Blood samples were collected at 3- to 12-month intervals to measure antibodies against islet cells, insulin, glutamate dehydroxylase and islet antigen 2. The families kept a record on the age at introduction of new foods, and for each visit completed a structured dietary questionnaire. The endpoint was repeated positivity for islet cell antibodies together with at least one of the other three antibodies. RESULTS The overall or exclusive duration of breastfeeding was not associated with the risk of developing the endpoint. An early age at introduction of fruits and berries (< or =4 months) was related to increased risk of developing positivity for the endpoint (hazard ratio [95% CI] for earliest tertile 2.02 [1.03-3.95] and for midtertile 1.97 [1.06-3.64] compared with latest tertile >4 months). Also, introducing roots between 3 and 3.9 months (midtertile) was related to increased risk of the endpoint (hazard ratio [95% CI] for the earliest tertile 1.04 [0.57-1.90] and for midtertile 1.82 [1.19-2.79] compared with latest tertile). These associations were independent of several putative socio-demographic and perinatal confounding factors. CONCLUSIONS/INTERPRETATION Our findings suggest that an early age at introduction of fruits and berries and roots associates independently with beta cell autoimmunity, contradicting earlier findings from smaller birth cohort studies.
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Affiliation(s)
- S M Virtanen
- Department of Health Promotion and Chronic Disease Prevention, National Public Health Institute, Mannerheimintie 166, 00300, Helsinki, Finland.
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Knip M, Veijola R, Virtanen SM, Hyöty H, Vaarala O, Akerblom HK. Environmental triggers and determinants of type 1 diabetes. Diabetes 2005; 54 Suppl 2:S125-36. [PMID: 16306330 DOI: 10.2337/diabetes.54.suppl_2.s125] [Citation(s) in RCA: 340] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Type 1 diabetes is perceived as a chronic immune-mediated disease with a subclinical prodromal period characterized by selective loss of insulin-producing beta-cells in the pancreatic islets in genetically susceptible subjects. A series of evidence supports a critical role of exogenous factors in the development of type 1 diabetes, such as 1) the fact that <10% of individuals with HLA-conferred diabetes susceptibility do progress to clinical disease, 2) a pairwise concordance of type 1 diabetes of <40% among monozygotic twins, 3) a more than 10-fold difference in the disease incidence among Caucasians living in Europe, 4) a several-fold increase in the incidence over the last 50 years, and 5) migration studies indicating that the disease incidence has increased in population groups who have moved from a low-incidence to a high-incidence region. This article discusses the trigger-booster hypothesis claiming that the diabetic disease process is triggered by an exogenous factor with definite seasonal variation and driven by one or several other environmental determinants. In addition, there are a series of modifying factors affecting the fate and pace of the process. Accordingly, progression to clinical type 1 diabetes typically requires the unfortunate combination of genetic disease susceptibility, a diabetogenic trigger, and a high exposure to a driving antigen.
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Affiliation(s)
- Mikael Knip
- Hospital for Children and Adolescents, University of Helsinki, P.O. Box 281, FI-00029 HUCH, Helsinki, Finland.
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18
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Virtanen SM, Knip M. Nutritional risk predictors of beta cell autoimmunity and type 1 diabetes at a young age. Am J Clin Nutr 2004; 78:1053-67. [PMID: 14668264 DOI: 10.1093/ajcn/78.6.1053] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Type 1 diabetes is an immune-mediated disease characterized by a preclinical prodrome during which beta cell autoimmunity proceeds at a variable rate. Large geographic differences and a conspicuous increase in incidence, especially among young children since the 1950s, and the relatively low concordance in identical twins are factors that favor a critical role of environmental factors in the etiology of this disease. Only approximately 5% or fewer subjects with HLA-conferred genetic susceptibility to type 1 diabetes actually develop the clinical disease. Breastfeeding, nicotinamide, zinc, and vitamins C, D, and E have been reported as possibly protecting against type 1 diabetes, whereas N-nitroso compounds, cow milk, increased linear growth, and obesity may increase the risk. Thus far, only the significance of infant feeding, cow milk, and vitamin D have been studied in both case-control and cohort settings. The major shortcoming of most studies done so far is that only single dietary exposures have been assessed at single time points. Putative nutritional and other confounding factors have received little attention as have the limitations of the dietary methods used. There is little firm evidence of the significance of nutritional factors in the etiology of type 1 diabetes. The availability of good markers of preclinical type 1 diabetes and of genetic risk have decreased the sample sizes needed and made longitudinal cohort studies of the assessment of children's diets feasible.
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Affiliation(s)
- Suvi M Virtanen
- Department of Epidemiology and Health Promotion, National Public Health Institute, Mannerheimintie 166, FIN-00300 Helsinki, Finland.
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Abstract
The diagnosis of type 1 diabetes versus other forms of diabetes such as type 2 diabetes is paramount to guiding proper therapy. Several islet autoantibodies have been identified that serve to diagnose immune-mediated, type 1a diabetes in clinically ambiguous cases. These autoantibodies also serve to predict type 1 diabetes in nondiabetic individuals. The most useful islet autoantibodies include islet cell cytoplasmic autoantibodies, insulin autoantibodies, glutamic acid decarboxylase autoantibodies, and insulinoma-associated-2 autoantibodies. Once type 1 diabetes can be safely and reliably prevented, large-scale islet autoantibody screening programs of the general pediatric population may be warranted. It is controversial whether islet autoantibodies influence the course of type 1 diabetes following diagnosis.
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Affiliation(s)
- William E Winter
- Department of Pathology, Laboratory Medicine & Immunology, University of Florida, Gainesville, Florida 32610-0275, USA.
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