Research Projects

The PEDIA group has experience from large scale international research projects focusing on humoral and cellular immunity, microbiome and environmental factors such as viruses and the role of diet in the development of beta-cell autoimmunity and type 1 diabetes.

Translational approaches to disease modifying therapy of type 1 diabetes: An innovative approach towards understanding and arresting type 1 diabetes (INNODIA)

The aim of INNODIA is to improve the understanding of how to predict and prevent the onset and progression of type 1 diabetes. Integral to this aim is clarifying the interaction between the environment and immune system, especially the beta cells. This study comprises 31 academic institutions and clinics, including the University of Helsinki, patient organizations and drug companies.

In the INNODIA study blood samples and data are collected on newly diagnosed patients with type 1 diabetes and their first degree relatives aged 1 to < 45 years. Patients with newly diagnosed type 1 diabetes were invited to come to a baseline study visit within 6 weeks from diagnosis, and are observed for 2 years. Unaffected family members are also screened for diabetes associated autoantibodies. Following the screening, autoantibody positive participants are invited to seven follow-up study visits over the subsequent 4 years.

The recruitment started in February 2017 in Cambridge, UK. In Finland, the recruitment started in August 2017, focusing on the Helsinki, Espoo and Oulu area. In April 2021 the recruitment of newly diagnosed patients with type 1 diabetes and their healthy family members have also been invited to the study in Turku. During spring 2021 the recruitment of healthy family members of the persons with type 1 diabetes has been expanded to Tampere, Lahti and Hämeenlinna regions. All diabetes autoantibody analyses within INNODIA are carried out in the PEDIA laboratory, University of Helsinki.

The recruitment of the newly diagnosed type 1 diabetics has been ended by the middle of November 2021 in all INNODIA study centers. Thank you for all the study participants! We are going to continue the recruitment of the healthy family members at the beginning of the year 2022. There is a break in recruitment at the end of the year 2021.

INNODIA is coordinated by University of Leuven  and University of Cambridge and funded by EU Horizon 2020 IMI2 Programme (Innovative Medicines Initiative), JDRF and Helmsley Charitable Trust.


TrialNet is an international network of leading academic institutions, physicians, scientists and healthcare teams dedicated to the prevention of type 1 diabetes.  TrialNet offers risk screening for relatives of people with type 1 diabetes and innovative intervention studies to explore ways to prevent clinical disease.

Pathway to Prevention Screening is the first step for all TrialNet prevention studies. Screening is offered free to relatives of people with type 1 diabetes to evaluate their risk of developing the disease. The screening can identify the early stages of type 1 diabetes years before any symptoms appear.  Those who are not family members and are known to have 1 or more islet antibodies are also eligible for screening. It also helps researchers learn more about how type 1 diabetes develops and plan new studies exploring ways to prevent it. 

One of the clinical studies is to test the drug Abatacept to find out whether it could delay or prevent progression of early stage type 1 diabetes to overt disease. The other study, LIFT is the long term follow-up for these individuals who are diagnosed with type 1 diabetes within TrialNet. Long-term follow up post-diagnosis may allow for addressing key gaps in our knowledge about the natural history of disease.

In Finland, the TrialNet coordinating center recruits relatives of patients with type 1 diabetes all around Finland together with the pediatric outpatient clinics.

In addition to the Finnish TrialNet center clinical centers are located in USA, Canada, Puerto Rico, Australia, New Zealand, Sweden, Germany, Italy and Great Britain. The international network is coordinated by the University of South Florida, Tampa, Florida, USA. TrialNet Finland is coordinated by University of Helsinki. The project is funded by JDRF and National Institute of Health (NIH).

Diabetes Register

The Finnish Pediatric Diabetes Register has been collecting data and blood samples from children diagnosed with any type of diabetes in the pediatric unit, and their first-degree family members since 2002. The holder of the register is Helsinki University Central Hospital, and it is led by Professor Mikael Knip.

The register covers more than 90% of children diagnosed with type 1 diabetes. By the end of 2018 over 8774 children with type 1 diabetes and more than 26,000 family members were included in the Diabetes Register. The Diabetes Register is collecting data on the family history of diabetes and autoimmune diseases, and the clinical status and metabolic decompensation of newly diagnosed children at the time of diagnosis.

Newly diagnosed child or adolescent with any type of diabetes and her/his family members will be asked to give blood sample for diabetes register collection. Data and samples will be used for research of diabetes and its complications. If family wish, the results of genetic susceptibility to type 1 diabetes and diabetes associated autoantibodies will be reported.

More information about this study: Study Nurse Sirpa Nolvi (e-mail:


Early Dietary Intervention and Later Signs of Beta-Cell Autoimmunity (EDIA)

The EDIA study is a clinical trial aimed at comparing the effects of weaning to two different formulas, i.e. an extensively hydrolyzed formula vs. a conventional formula on intestinal permeability, gut microbiota, Th17 immunity, as well as serum metabolome and proteome. The hypothesis is that and extensively hydrolyzed casein formula decreases intestinal permeability, down-regulates IL-17 immunity and proinflammatory lysophoshatidylcholines in serum, and stabilizes lactobacilli levels in the gut microbiota when compared to a conventional cow’s milk formula.

The parent of infants to be born in the area of Tampere University Hospital were invited during pregnancy to take part in the EDIA study. The recruitment was started in March 2013 and the last recruited infant was born in August 2015. The study population comprised 82 newborn infants with HLA-conferred susceptibility to type 1 diabetes. The infants were followed until the age of 12 months, where after the families were offered continued follow-up within the DIPP study.

The mothers were encouraged to exclusively breastfeed their infants as long as possible. The timing of weaning and introduction of study formula was left to the mother. The infants were randomized to be weaned to one of the two study formulas: the extensively hydrolyzed casein formula or the conventional cow’s milk formula. Foods containing cow’s milk proteins, beef, and veal were excluded from the diet during the 9-month intervention period. The first results will be available in year 2018.

EDIA Study was coordinated by University of Helsinki and sponsored by NIDDK; National Institute of Health as well as Finska Läkaresällskapet and Medicinska Understödsföreningen Liv och Hälsa r.f.


Trial to Reduce IDDM in the Genetically at Risk (TRIGR)

TRIGR study was the largest double-blind randomized clinical trial of 2159 infants with HLA-conferred disease susceptibility and a first-degree relative with type 1 diabetesever aimed at primary prevention of type 1 diabetes.  The study set out to determine whether delayed exposure to cow´s milk proteins being the first complex proteins that a baby is normally exposed to, will reduce the risk of developing type 1 diabetes later in life. The hypothesis was that weaning to an extensively hydrolyzed formula decreases the cumulative incidence of diabetes-associated autoantibodies and type 1 diabetes.

TRIGR subjects were recruited from May 2002 to January 2007 in 78 study centers in 15 countries (Finland, Sweden, Estonia, Germany, The Netherlands, Luxembourg, Switzerland, Poland, Hungary, Czech Republic, Spain, Italy, Australia, United States and Canada). The mothers were recommended to breastfeed as long as possible. Whenever breast milk was not available in sufficient amounts the mother was asked to give her baby the study formula being either an extensively hydrolyzed casein formula or a conventional cow's milk-based formula. The minimum duration of the study formula exposure was 60 days by 6.8 months of age.

The first end-point results in 2014 showed, there was no difference by the age of 7 years in the appearance of diabetes-associated autoantibodies between the casein formula and conventional cow´s milk formula groups (Knip M et al, JAMA 2014).The second end-point results, comparing the risk of type 1 diabetes between the study groups, were published in the first 2018 issue of the Journal of the American Medical Association (JAMA). Weaning to an extensively hydrolyzed casein formula during infancy did not result in a reduction in the incidence of type 1 diabetes compared to regular intact cow's milk-based formula after 11.5 years of follow up. All children were observed until February 2017, at which time the participants were 10-14 years old.  Accordingly, there is no evidence to revise the current dietary recommendations for infants carrying high genetic risk for type 1 diabetes.

The TRIGR study was coordinated by University of Helsinki and sponsored by the National Institute of Health (NIH), JDRF, European Union (EU), European Foundation for the Study of Diabetes (EFSD) and Academy of Finland.


Pathogenesis of type 1 diabetes-testing the hygiene hypothesis (DIABIMMUNE)

The DIABIMMUNE study aims at assessing the role of environmental factors focusing on the role of hygiene in the development of allergies and immune-mediated diseases, type 1 diabetes in particular. The populations in Finland, Estonia and Russian Karelia have relatively similar distributions of HLA genotypes predispoising to autoimmunity but a marked difference in the incidence of type 1 diabetes and in the prevalence of allergies, asthma and celiac disease. This EU-sponsored study comprised 12 academic partners, including the University of Helsinki, which functioned as the coordinating center.

The DIABIMMUNE study started in 2008 in three centers: Espoo (Finland), Tartu (Estonia) and Petrozavodsk (Russian Karelia). The study comprises two cohorts: a birth cohort (BC) and a young children cohort (YCC). In the birth cohort, infants were followed from birth till the age of 3 years. The enrolment criteria in the BC cohort was a HLA genotype conferring increased risk for autoimmunity, while the participants in the YCC were from the general population, recruited at the age of 3 years and observed till the age of  5 years. Altogether there were more than 800 infants in the BC- and over 3600 young children in the YCC cohort. Samples were collected to analyze type 1 diabetes and celiac disease autoantibodies, allergies, function of regulatory T cell, infections and gut microbiome. In addition, information about diet, allergies, infections and use of drugs was collected. The recruitment and the follow-up have been completed but the analysis of the collected samples and data is continuing.

The analysis of the intestinal microbiome showed a decrease in the microbial diversity after seroconversion to autoantibody positivity in those children who progressed to clinical diseases (Kostic AD et al. Cell Host & Microbe 2015). Predominance of Bacteroides species, which are weak immune stimulators, was common in Finnish and Estonian children, whereas LPS procuding E.coli with a strong immunostimulatory potency was more abundant in Russian Karelian children than in Finnish and Estonian peers (Vatanen T et al. Cell 2016).

DIABIMMUNE was sponsored by EU FP7 program as well as Finska Läkaresällskapet and Medicinska Understödsföreningen Liv och Hälsa r.f.


The diabetes prediction and prevention study (DIPP)

The DIPP study was launched in 1994 in three Finnish university hospitals (Turku, Tampere, Oulu). The purpose of the DIPP project is to study the risk factors and pathomechanisms of type 1 diabetes in order to find new prevention and treatment methods. There are several ancillary studies clarifying potential environmental and gene-environmental factors contributing to the induction of beta-cell autoimmunity and overt diabetes.

In the DIPP study, newborn infants are screened for HLA-conferred susceptibility to type 1 diabetes, and those with increased genetic risk are asked to join the follow-up program with study center visits every 3-12 months. Diabetes-associated autoantibodies (ICA, IAA, GADA and IA-2A) are analysed from all samples in the DIPP laboratory, University of Oulu. ZnT8A are analyzed from DIPP samples in the PEDIA laboratory, University of Helsinki. In addition to autoantibody analysis from serum samples, data on infections, diet, allergies, and vaccinations are collected at every visit.

Since 1994, over 220, 000 have been screened, and close to 18,000 families and their infants with increased HLA risk for type 1 diabetes have joined the follow-up study.

Results from the DIPP study suggest that viral infections and dietary factors may affect the development of type 1 diabetes. Enterovirus infections have been implicated as a definite risk factor for type 1 diabetes (Hyöty 2016). Recent data indicate that Coxsackie B1 virus functions as a trigger of the disease process in a considerable proportion of children who progress to clinical type 1 diabetes. Gut microbiome studies have shown that bacterial diversity diminishes, and bacteria composition is dominated by non-butyrate-producing species in children that later present with clinical type diabetes (Giongo et al. 2011). Recent results suggest that fatty acids, derived primarily from fish in maternal diet during pregnancy or lactation, may protect infants against pre-type 1 diabetes. Breastfeeding and fatty acids obtained from breast milk showed also a protective association (Niinistö et al. 2017). Early introduction of solid foods before the age 4 months was associated with increased risk to develop pre-diabetes before the age of 3 years (Hakola et al. 2017).


Academy of Finland Centre of Excellence in Molecular Systems Immunology and Physiology Research (SyMMyS)

The overall objective of SyMMyS, Academy of Finland Centre of Excellence in Molecular Systems Immunology and Physiology Research (2012-2017), is to understand the molecular mechanisms that control the immune system as well as the interactions between the immune system and other physiological systems in health and disease, and to translate this knowledge into novel treatment and prevention strategies of inflammatory and immune-mediated disorders, with specific focus on type 1 diabetes.

The studies help establish interactions between the metabolic regulation and the immune system. Along the way, we evaluate the role of metabolism in early stages of autoimmune diseases as well as molecular mechanisms controlling T-cell differentiation.

T-cell plasticity

Plasticity of Th17 cells as a marker of aggressive beta-cell destruction

Although beta-cell autoantibodies are useful for the identification of the children at risk of type 1 diabetes, the prediction of the progression from beta-cell autoimmunity to clinical diabetes is not straightforward, and the time from the induction of autoantibodies, i.e. seroconversion, to clinical diabetes varies from months to several years in autoantibody-positive children. Accordingly biomarkers of aggressive beta-cell destruction are needed.

In this project we study whether phenotypic instability of Th17 cells could be used for prediction of aggressive beta-cell destruction and for the identification of individuals at high risk for clinical diabetes. The identification of those children who progress from beta-cell autoimmunity to clinical disease is not important only for prediction of progression, but also for the selection of cases to be recruited for clinical trials. Furthermore, the plasticity of IL-17 immunity as a biomarker for beta-cell destruction could also be used for monitoring the effects of interventions and for the prediction of the residual beta-cell function after the diagnosis of type 1 diabetes.

In this project, children at genetic risk and multiple autoantibodies and children with recent-onset type 1 diabetes are followed for 2 years and Th17 immunity is monitored at 6-month intervals. The relationship between Th17 immunity and metabolic parameters reflecting beta-cell function are analyzed to gain an insight into the clinical relevance of up-regulation of Th17 immunity. The project was started in 2015 and the first results will be published in 2018. Professor Outi Vaarala has functioned as the Principal Investigator for this project sponsored by JDRF.

Inhibition of T-cell plasticity by RORgT inhibitors

Th17 cells show substantial phenotypic plasticity and in addition to IL-17 they are able to secrete other effector cytokines as well.  Animal studies suggest that the plasticity of the Th17 cells and the development of IL-17/ IFN-γ or IL-17/GM-CSF co-producers in particular is associated with the pathogenicity of Th17 cells.

Recently, we reported increased IFN-γ mRNA expression in Th17 cells in children with late pre-clinical T1D and impaired glucose tolerance or clinical type 1 diabetes. Therefore, the up-regulation of Th17 immunity and simultaneous expression of IFN-γ and IL-17 by Th17 cells could contribute to the destruction of beta cells and the development of beta-cell autoimmunity and clinical T1D. Moreover, up-regulation of Th17 immunity is associated with the disease pathogenesis in multiple sclerosis. Th17 differentiation is driven by STAT3 and SMAD signaling cascades, which activate the nuclear receptor RORgT, the master regulator of Th17 cells. Recently, blocking the function of RORgT was demonstrated to prevent disease pathogenesis in animal models of autoimmune diabetes and multiple sclerosis.

In this research project we study whether pharmacological inhibition of the function of transcription factor RORgT can inhibit the development of pathogenic Th17 and Tc17 cells with increased plasticity in vitro in children with recent-onset type 1 diabetes and adult patients with multiple sclerosis.

The project was started in  2016 and the first results will be published in 2018. The project was carried out in collaboration with professor Pentti Tienari and adjunct professor Päivi Miettinen from the Helsinki University Central Hospital (HUCH). The senior researcher Jarno Honkanen is the Principal Investigator of the project which was sponsored by AstraZeneca.


Gut and diabetes

Gut as an immune regulator in type 1 diabetes

Recent studies suggest that the composition of gut microbiota is altered in pre-diabetic children who have HLA-related risk of type 1 diabetes and beta-cell autoantibodies. According to the animal studies, changes in the gut microbiota modulate the development of autoimmune diabetes. Gut microbiota modulates the function of the immune system by its effects on the innate immune system, such as the intestinal epithelial cells and dendritic cells, which express microbial pattern-recognition receptors. Gut microbiota also affects the function of the adaptive immune system and development of T cell phenotype.

Here, we study the association of gut microbiota with the immunological alterations, such as up regulation of IL-17 immunity, development of T-cell plasticity and intestinal inflammation in the developments of type 1 diabetes. The immunological alterations and the composition of fecal microbiota are studied in the follow-up samples of children at risk of type 1 diabetes in order to understand the temporal association between these factors. The ultimate aim in the project is to identify bacterial species or strains as candidate regulators of immunological changes in type 1 diabetes, and to develop prevention strategies of beta-cell destruction targeting gut microbiota and intestinal mucosal immunity.

The project was started in 2014 and the first results will be published in 2018. Professor Outi Vaarala is the Principal Investigator. The study is sponsored by the Academy of Finland, the Finnish Diabetes Research Foundation and European Foundation for the Study of Diabetes (EFSD).


Effect of early diet and virus infections on immune regulation and the development islet autoimmunity (DIVIA)

The study will yield important new information about the main environmental candidate risk factors in the pathogenesis of type 1 diabetes (T1D) utilizing the setup of TRIGR (dietary intervention). The aim is to evaluate associations and interactions between n-3 fatty acids, vitamin D, cow’s milk and viral infections with indicators of immune regulation and inflammation as well as induction of islet autoimmunity. In this project LID performs multiplexed Luminex analysis of concentrations of circulating cytokines, chemokines and growth factors in the serum samples collected in early childhood from the children that have participated the TRIGR study. The project was started in 2016 and will be completed by the end of 2019. Principal investigator of TRIGR-DIVIA is professor Suvi Virtanen from the National Institute for Health and Welfare. The project is a collaboration between the National Institute for health and welfare, University of Helsinki, University of Tampere and University of South Florida.