Arvo building, Lecture room F025, address: Lääkärinkatu 1.
Doctoral defence of M.Sc. Sami Oikarinen
The field of science of the dissertation is Virology.
The opponent is Professor Antonio Toniolo (University of Insubria, Italy). Professor Heikki Hyöty acts as the custos.
The language of the dissertation defence is English.
Association between enterovirus infections and type 1 diabetes in different countries
The present study evaluates a possible connection between enterovirus (EV) infections and type 1 diabetes (T1D) focusing on the following research questions: 1) The association between enterovirus infections and T1D was evaluated in different stages of the T1D process, 2) the specific role of the six coxsackie B viruses (CBVs) was studied in the development of T1D and 3) these associations were evaluated in six different countries.
The research population consisted of three independent case-control cohorts collected from various countries. One cohort, from Finland, included children who were followed from birth until the diagnosis of T1D. Another cohort, from the USA, included children followed from the appearance of T1D associated autoantibodies until the development of T1D. A third series included newly diagnosed T1D patients from Finland, Sweden, the UK, France and Greece. In total, these cohorts included 337 children who developed T1D, 90 autoantibody positive children and 389 autoantibody negative non-diabetic control children. Enterovirus infections were diagnosed using RT-PCR to detect enterovirus RNA in serum and stool samples. In addition, enterovirus specific antibodies were measured from serum samples using ELISA and plaque neutralization assays.
Enterovirus infections were more common in children who developed T1D than in control children. This difference was most marked during the time period of six months prior to seroconversion to T1D associated autoantibodies. In addition, autoantibody positive children who developed T1D had more enterovirus infections than children who did not develop the disease. However, the enterovirus RNA was not detected at the onset of clinical T1D in serum or stool samples.
When the risk association of six different CBV serotypes with T1D was analyzed in Finland, Sweden, the UK, France and Greece, CBV1 infections were more common in case children than in the control group. This finding was similar in all five study populations. The prevalence of antibodies against CBV2-6 did not differ between case and control groups.
The results of this study support the hypothesis that enterovirus infections may contribute to the development of T1D. CBV1 may especially have a specific role in triggering and accelerating the disease process. However, confirmation of causality between the enterovirus infections and the disease needs additional studies, such as intervention trials with vaccinations or antiviral drugs.
The dissertation is published in the publication series of Acta Universitatis Tamperensis; 2228, Tampere University Press, Tampere 2016. ISBN 978-952-03-0270-2, ISSN 1455-1616. The dissertation is also published in the e-series Acta Electronica Universitatis Tamperensis; 1728, Tampere University Press 2016. ISBN 978-952-03-0271-9, ISSN 1456-954X.
Sami Oikarinen, Tel. +358 50 328 1500, Sami.Oikarinen@uta.fi