Assessment of Enterovirus Antibodies during Early Childhood Using a Multiplex Immunoassay.

Enteroviruses are a group of positive single-stranded viruses that belong to the Picornaviridae family. They regularly infect humans and cause symptoms ranging from the common cold and hand-foot-and-mouth disease to life-threatening conditions, such as dilated cardiomyopathy and poliomyelitis. Enteroviruses have also been associated with chronic immune-mediated diseases, such as type 1 diabetes, celiac disease, and asthma. Studying these disease-pathogen connections is challenging due to the high prevalence of enterovirus infections in the population and the transient appearance of the virus during the acute infection phase, which limit the identification of the causative agent via methods based on the virus genome. Serological assays can detect the antibodies induced by acute and past infections, which is useful when direct virus detection is not possible. We describe in this immuno-epidemiological study how the antibody levels against VP1 proteins from eight different enterovirus types, representing all seven of the human infecting enterovirus species, vary over time. VP1 responses first significantly (P < 0.001) decline until 6 months of age, reflecting maternal antibodies, and they then start to increase as the infections accumulate and the immune system develops. All 58 children in this study were selected from the DiabImmnune cohort for having PCR-confirmed enterovirus infections. Additionally, we show that there is great, although not complete, cross-reactivity of VP1 proteins from different enteroviruses and that the response against 3C-pro could reasonably well reflect the recent Enterovirus infection history (ρ = 0.94, P = 0.017). The serological analysis of enterovirus antibodies in sera from children paves the way for the development of tools for monitoring the Enterovirus epidemics and associated diseases. IMPORTANCE Enteroviruses cause a wide variety of symptoms ranging from a mild rash and the common cold to paralyzing poliomyelitis. While enteroviruses are among the most common human pathogens, there is a need for new, affordable serological assays with which to study pathogen-disease connections in large cohorts, as enteroviruses have been linked to several chronic illnesses, such as type 1 diabetes mellitus and asthma exacerbations. However, proving causality remains an issue. In this study, we describe the use of an easily customizable multiplexed assay that is based on structural and nonstructural enterovirus proteins to study antibody responses in a cohort of 58 children from birth to 3 years of age. We demonstrate how declining maternal antibody levels can obscure the serological detection of enteroviruses before the age of six months and how antibody responses to nonstructural enterovirus proteins could be interesting targets for serodiagnosis.

Indoor green wall affects health-associated commensal skin microbiota and enhances immune regulation: a randomized trial among urban office workers.

Urbanization reduces microbiological abundance and diversity, which has been associated with immune mediated diseases. Urban greening may be used as a prophylactic method to restore microbiological diversity in cities and among urbanites. This study evaluated the impact of air-circulating green walls on bacterial abundance and diversity on human skin, and on immune responses determined by blood cytokine measurements. Human subjects working in offices in two Finnish cities (Lahti and Tampere) participated in a two-week intervention, where green walls were installed in the rooms of the experimental group. Control group worked without green walls. Skin and blood samples were collected before (Day0), during (Day14) and two weeks after (Day28) the intervention. The relative abundance of genus Lactobacillus and the Shannon diversity of phylum Proteobacteria and class Gammaproteobacteria increased in the experimental group. Proteobacterial diversity was connected to the lower proinflammatory cytokine IL-17A level among participants in Lahti. In addition, the change in TGF-ß1 levels was opposite between the experimental and control group. As skin Lactobacillus and the diversity of Proteobacteria and Gammaproteobacteria are considered advantageous for skin health, air-circulating green walls may induce beneficial changes in a human microbiome. The immunomodulatory potential of air-circulating green walls deserves further research attention.

A hexavalent Coxsackievirus B vaccine is highly immunogenic and has a strong protective capacity in mice and nonhuman primates.

Coxsackievirus B (CVB) enteroviruses are common human pathogens known to cause severe diseases including myocarditis, chronic dilated cardiomyopathy, and aseptic meningitis. CVBs are also hypothesized to be a causal factor in type 1 diabetes. Vaccines against CVBs are not currently available, and here we describe the generation and preclinical testing of a novel hexavalent vaccine targeting the six known CVB serotypes. We show that the vaccine has an excellent safety profile in murine models and nonhuman primates and that it induces strong neutralizing antibody responses to the six serotypes in both species without an adjuvant. We also demonstrate that the vaccine provides immunity against acute CVB infections in mice, including CVB infections known to cause virus-induced myocarditis. In addition, it blocks CVB-induced diabetes in a genetically permissive mouse model. Our preclinical proof-of-concept studies demonstrate the successful generation of a promising hexavalent CVB vaccine with high immunogenicity capable of preventing CVB-induced diseases.

A preclinical assessment to repurpose drugs to target type 1 diabetes-associated type B coxsackieviruses.

AIM: To screen several antiviral drugs systematically for their efficacy against type B coxsackieviruses. METHODS: Ten drugs with different antiviral mechanisms were analysed for their efficacy against prototype strains of type B coxsackieviruses in A549 cells. Cell viability was quantified in fixed cells using a colorimetric assay. Median effective dose was interpolated from the triplicated experiments and the dose-response curves were generated for each drug-virus combination. Drug cytotoxicity was similarly quantified and selectivity indices calculated. RESULTS: Hizentra, pleconaril, fluoxetine, norfluoxetine, ribavirin, favipiravir, and guanidine hydrochloride were able to abrogate infection by all tested viruses, with the exception of complete inefficacy of pleconaril against coxsackievirus B3 and favipiravir against coxsackievirus B2. The effective doses for Hizentra, enviroxime, ribavirin, favipiravir, and pleconaril were clearly below their therapeutic serum concentrations, while the effective concentrations of fluoxetin, norfluoxetine and itraconazole exceeded their therapeutic serum concentrations. Lovastatin and azithromycin did not efficiently block type B coxsackieviruses. CONCLUSION: Hizentra, enviroxime, pleconaril, ribavirin, and favipiravir are effective against type B coxsackieviruses in vitro in their therapeutic serum concentrations. These antiviral drugs are therefore attractive candidates for type 1 diabetes prevention/treatment trials. They can also be used in other clinical conditions caused by type B coxsackieviruses.

High prevalence of selected viruses and parasites and their predictors in Malawian children.

Enteric pathogens have been related to child undernutrition. Whereas there are lots of data on enteric bacterial microbiota and infections, much less is known about the incidence of prevalence of intestinal colonisation with viruses or important parasitic species. This study assessed the presence of selected viruses and parasites in stools of 469, 354, 468 Malawian children at 6, 12 and 18 months. We also assessed environmental predictors of the presence of viruses and parasites among 6-month infants. Microbial presence was documented using real-time polymerase chain reaction (PCR). Enteroviruses were identified in 68%, 80% and 81% of the stool samples at 6, 12 and 18 months children, rhinovirus in 28%, 18% and 31%, norovirus in 24%, 22% and 16%, parechovirus in 23%, 17% and 17%, rotavirus in 3%, 1% and 0.6%, Giardia lamblia in 9.6%, 23.5% and 26%, and Cryptosporidium (spp.) in 6%, 8% and 2% of the 6, 12 and 18 months stool samples. Dry season (May-October) was associated with a low infection rate of enterovirus, norovirus and Cryptosporidium (spp.). Higher father's education level, less number of person in the household and higher sanitation were associated with a low infection rate of enterovirus, norovirus and rotavirus, respectively. The results suggest that the prevalence of asymptomatic viral and parasitic infections is high among Malawian children and that the family's living conditions and seasonality influence the rate of infections.

Early childhood infections precede development of beta-cell autoimmunity and type 1 diabetes in children with HLA-conferred disease risk.

BACKGROUND: The etiology of type 1 diabetes (T1D) is largely unknown. Infections and microbial exposures are believed to play a role in the pathogenesis and in the development of islet autoimmunity in genetically susceptible individuals. OBJECTIVE: To assess the relationships between early childhood infections, islet autoimmunity, and progression to T1D in genetically predisposed children. METHODS: Children with human leukocyte antigen (HLA)-conferred disease susceptibility (N=790; 51.5% males) from Finland (n = 386), Estonia (n = 322), and Russian Karelia (n = 82) were observed from birth up to the age of 3 years. Children attended clinical visits at the age of 3, 6, 12, 18, 24, and 36 months. Serum samples for analyzing T1D-associated autoimmune markers were collected and health data recorded during the visits. RESULTS: Children developing islet autoimmunity (n = 46, 5.8%) had more infections during the first year of life (3.0 vs 3.0, mean rank 439.1 vs 336.2; P = .001) and their first infection occurred earlier (3.6 vs 5.0 months; P = .005) than children with no islet autoimmunity. By May 2016, 7 children (0.9%) had developed T1D (progressors). Compared with non-diabetic children, T1D progressors were younger at first infection (2.2 vs 4.9 months; P = .004) and had more infections during the first 2 years of life (during each year 6.0 vs 3.0; P = .001 and P = .027, respectively). By 3 years of age, the T1D progressors had twice as many infections as the other children (17.5 vs 9.0; P = .006). CONCLUSIONS: Early childhood infections may play an important role in the pathogenesis of T1D. Current findings may reflect either differences in microbial exposures or early immunological aberrations making diabetes-prone children more susceptible to infections.

Coxsackie-adenovirus receptor expression is enhanced in pancreas from patients with type 1 diabetes.

OBJECTIVES: One of the theories connecting enterovirus (EV) infection of human islets with type 1 diabetes (T1D) is the development of a fertile field in the islets. This implies induction of appropriate proteins for the viral replication such as the coxsackie-adenovirus receptor (CAR). The aim of this study was to investigate to what extent CAR is expressed in human islets of Langerhans, and what conditions that would change the expression. DESIGN: Immunohistochemistry for CAR was performed on paraffin-embedded pancreatic tissue from patients with T1D (n=9 recent onset T1D, n=4 long-standing T1D), islet autoantibody-positive individuals (n=14) and non-diabetic controls (n=24) individuals. The expression of CAR was also examined by reverse transcription PCR on microdissected islets (n=5), exocrine tissue (n=5) and on explanted islets infected with EV or exposed to chemokines produced by EV-infected islet cells. RESULTS: An increased frequency of patients with T1D and autoantibody-positive individuals expressed CAR in the pancreas (p<0.039). CAR staining was detected more frequently in pancreatic islets from patients with T1D and autoantibody-positive subjects (15/27) compared with (6/24) non-diabetic controls (p<0.033). Also in explanted islets cultured in UV-treated culture medium from coxsackievirus B (CBV)-1-infected islets, the expression of the CAR gene was increased compared with controls. Laser microdissection of pancreatic tissue revealed that CAR expression was 10-fold higher in endocrine compared with exocrine cells of the pancreas. CAR was also expressed in explanted islets and the expression level decreased with time in culture. CBV-1 infection of explanted islets clearly decreased the expression of CAR (p<0.05). In contrast, infection with echovirus 6 did not affect the expression of CAR. CONCLUSIONS: CAR is expressed in pancreatic islets of patients with T1D and the expression level of CAR is increased in explanted islets exposed to proinflammatory cytokines/chemokines produced by infected islets. T1D is associated with increased levels of certain chemokines/cytokines in the islets and this might be the mechanism behind the increased expression of CAR in TID islets.

Human parechovirus and the risk of type 1 diabetes.

Human parechoviruses (HPeVs) are RNA viruses associated mainly with mild gastrointestinal and respiratory infections in children and also cause neonatal sepsis and CNS infections. Human enteroviruses, close relatives of HPeVs, associate with the development of type 1 diabetes. In this study, the potential role of HPeV infections in promoting beta cell autoimmunity was investigated by analyzing stool samples of 54 prediabetic case and 134 healthy control children for the presence of HPeV RNA and comparing the derived infection frequencies. All 188 children were participants of the Finnish prospective Diabetes Prediction and Prevention study. Viral RNA was screened for using an HPeV-specific RT-PCR method coupled to liquid hybridization of the PCR product. The overall HPeV infection frequency did not differ between prediabetic case and control children. However, case boys had more HPeV positive samples in the 6-month period before becoming autoantibody positive, when compared to the matching time-period in controls (P < 0.01). HPeV infection at a young age does not appear to play a major role in the development of beta-cell autoimmunity. In boys, however, HPeVs showed time-dependent association with the first detection of diabetes-associated autoantibodies. Thus, in boys, HPeV infections cannot be excluded as a gender-specific risk factor which promotes the development of type 1 diabetes.

Next-generation sequencing for viruses in children with rapid-onset type 1 diabetes.

AIMS/HYPOTHESIS: Viruses are candidate causative agents in the pathogenesis of autoimmune (type 1) diabetes. We hypothesised that children with a rapid onset of type 1 diabetes may have been exposed to such agents shortly before the initiation of islet autoimmunity, possibly at high dose, and thus study of these children could help identify viruses involved in the development of autoimmune diabetes. METHODS: We used next-generation sequencing to search for viruses in plasma samples and examined the history of infection and fever in children enrolled in The Environmental Determinants of Diabetes in the Young (TEDDY) study who progressed to type 1 diabetes within 6 months from the appearance of islet autoimmunity, and in matched islet-autoantibody-negative controls. RESULTS: Viruses were not detected more frequently in plasma from rapid-onset patients than in controls during the period surrounding seroconversion. In addition, infection histories were found to be similar between children with rapid-onset diabetes and control children, although episodes of fever were reported less frequently in children with rapid-onset diabetes. CONCLUSIONS/INTERPRETATION: These findings do not support the presence of viraemia around the time of seroconversion in young children with rapid-onset type 1 diabetes.

Enterovirus infections in early childhood and the risk of atopic disease--a nested case-control study.

BACKGROUND: Enterovirus infections in childhood have been associated with a reduced risk of atopy in cross-sectional studies. OBJECTIVE: To study the relation between enterovirus infections in the first 2 years of life and atopic disease with IgE sensitization in a prospective study setting. METHODS: This was a nested case-control study among children who had been followed from birth. Neutralizing antibodies against 12 enterovirus serotypes were analysed at the age of 2 years from 71 atopic children and 142 non-atopic control children. Atopy was defined as having an atopic disease and IgE antibodies against at least one aeroallergen by the age of 5 years. RESULTS: Cumulative exposure to different enterovirus serotypes was inversely associated with atopy [odds ratio (OR) 0.73; 95% confidence interval (CI): 0.56-0.96]. The most pronounced protection was seen when echoviruses were analysed as a separate group (OR 0.63; 95%CI: 0.46-0.88). CONCLUSIONS AND CLINICAL RELEVANCE: We propose that exposure to several different enteroviruses in early childhood is inversely associated with atopic diseases. Our results support the hypothesis that repeated microbial infections in early life may protect from atopic sensitization and atopic diseases.

Introduction of complementary foods in infancy and atopic sensitization at the age of 5 years: timing and food diversity in a Finnish birth cohort.

OBJECTIVE: To study the associations between timing and diversity of introduction of complementary foods during infancy and atopic sensitization in 5-year-old children. METHODS: In the Finnish DIPP (type 1 diabetes prediction and prevention) birth cohort (n = 3781), data on the timing of infant feeding were collected up to the age of 2 years and serum IgE antibodies toward four food and four inhalant allergens measured at the age of 5 years. Logistic regression was used for the analyses. RESULTS: Median duration of exclusive and total breastfeeding was 1.4 (interquartile range: 0.2-3.5) and 7.0 (4.0-11.0) months, respectively. When all the foods were studied together and adjusted for confounders, short duration of breastfeeding decreased the risk of sensitization to birch allergen; introduction of oats <5.1 months and barley <5.5 months decreased the risk of sensitization to wheat and egg allergens, and oats additionally associated with milk, timothy grass, and birch allergens. Introduction of rye <7.0 months decreased the risk of sensitization to birch allergen. Introduction of fish <6 months and egg ≤11 months decreased the risk of sensitization to all the specific allergens studied. The introduction of <3 food items at 3 months was associated with sensitization to wheat, timothy grass, and birch allergens; the introduction of 1-2 food items at 4 months and ≤4 food items at 6 months was associated with all endpoints, but house dust mite. These results were particularly evident among high-risk children when the results were stratified by atopic history, indicating the potential for reverse causality. CONCLUSIONS: The introduction of complementary foods was consecutively done, and with respect to the timing of each food, early introduction of complementary foods may protect against atopic sensitization in childhood, particularly among high-risk children. Less food diversity as already at 3 months of age may increase the risk of atopic sensitization.

Early seroconversion and rapidly increasing autoantibody concentrations predict prepubertal manifestation of type 1 diabetes in children at genetic risk.

AIMS/HYPOTHESIS: The aim of the study was to investigate the timing of the appearance of autoantibodies associated with type 1 diabetes between birth and puberty, the natural fate of these autoantibodies and the predictive power of autoantibody concentrations for early progression to clinical diabetes. METHODS: Children were recruited to the Type 1 Diabetes Prediction and Prevention Project, an ongoing study based on HLA-conferred genetic risk. Autoantibodies against islet cells, insulin, GAD65 and islet antigen 2 were analysed at 3-12 month intervals, starting from birth. RESULTS: During the follow-up, 1,320 children (18.4% of the cohort of 7,165 children) were autoantibody positive in at least one sample. Altogether, 184 autoantibody-positive children progressed to type 1 diabetes. Seroconversion occurred at an early age in the progressors (median 1.5 years), among whom 118 (64%) and 150 (82%) seroconverted to autoantibody positivity before the age of 2 and 3 years, respectively. The incidence of seroconversion peaked at 1 year of age. Compared with other autoantibody-positive children, the median autoantibody levels were already markedly higher 3 to 6 months after the seroconversion in children who later progressed to diabetes. CONCLUSIONS/INTERPRETATION: Early initiation of autoimmunity and rapid increases in autoantibody titres strongly predict progression to overt diabetes before puberty, emphasising the importance of early life events in the development of type 1 diabetes.

The association between prior infection with five serotypes of Coxsackievirus B and incident type 2 diabetes mellitus in the EPIC-Norfolk study.

AIMS/HYPOTHESIS: Infections with Coxsackieviruses have been linked to beta cell dysfunction. Given the importance of beta cell dysfunction in the aetiology of type 2 diabetes, we hypothesised that prior infection with Coxsackieviruses B would increase the risk of type 2 diabetes. The aims of the study were to estimate cross-sectional associations between potential predictors of previous infection and seropositivity for Coxsackievirus B serotypes 1-5 (CBV1-5), and then to assess the association between seropositivity and incident type 2 diabetes. METHODS: Using a case-cohort design nested within the European Prospective Investigation of Cancer (EPIC)-Norfolk study, we ascertained n = 603 cases of incident type 2 diabetes. From within the entire cohort we identified a random subcohort of n = 835, without diabetes at baseline. The presence of Coxsackievirus B neutralising antibodies against serotypes 1-5 was assessed using a plaque neutralisation assay. Weighted Cox regression was used to examine the association between presence of antibodies to CBV1-5 and the development of type 2 diabetes. RESULTS: Seropositivity in the subcohort for CBV1-5 was 50%, 67%, 66%, 75% and 45%, respectively. After adjustment for age, sex, BMI, physical activity and family history of diabetes, the presence of antibodies against CBV1-5 was not associated with incident type 2 diabetes, over a mean follow-up of 5.7 years (HR [95% CIs] 0.94 [0.72,1.25], 0.92 [0.68, 1.23], 1.33 [0.98,1.81], 1.16 [0.83,1.61] and 1.03 [0.77,1.39] for CBV1-5, respectively). CONCLUSIONS/INTERPRETATION: The presence of antibodies against any of five serotypes of Coxsackievirus B was not associated with incident type 2 diabetes.

Interaction of enterovirus infection and cow's milk-based formula nutrition in type 1 diabetes-associated autoimmunity.

BACKGROUND: Enteral virus infections and early introduction of cow's milk (CM)-based formula are among the suggested triggers of type 1 diabetes (T1D)-associated autoimmunity, although studies on their role have remained contradictory. Here, we aimed to analyse whether interactions between these factors might clarify the controversies. MATERIALS: The study population comprised 107 subjects developing positivity for at least two T1D-associated autoantibodies and 446 control subjects from the Finnish diabetes prediction and prevention cohort. Enterovirus, rotavirus, adenovirus, respiratory syncytial virus and bovine insulin-binding antibodies were analysed from prospective serum samples at 3-24 months of age. Data on infant cow's milk exposure were available for 472 subjects: 251 subjects were exposed to cow's milk before 3 months of age and 221 subjects later in infancy. RESULTS: Signs of an enterovirus infection by 12 months of age were associated with the appearance of autoimmunity among children who were exposed to cow's milk before 3 months of age. Cox regression analysis revealed a combined effect of enterovirus infection and early cow's milk exposure for the development of ICA and any of the biochemically defined autoantibodies (p = 0.001), of IAA (p = 0.002), GADA (p = 0.001) and IA-2A (p = 0.013). CONCLUSIONS: The effect of enterovirus infection on the appearance of T1D-associated autoimmunity seems to be modified by exposure to cow's milk in early infancy suggesting an interaction between these factors. Moreover, these results provide an explanation for the controversial findings obtained when analysing the effect of any single one of these factors on the appearance of T1D-associated autoimmunity.

DETECTION OF LACTOBACILLI IN MONTHLY MAIL-IN STOOL SAMPLES FROM 3-18 MONTHS OLD INFANTS AT GENETIC RISK FOR TYPE 1 DIABETES.

The feasibility to detect lactobacilli in mail-in infant stools collected monthly from 3-18 months old children was investigated. The aim was to determine total lactobacilli and Lactobacillus plantarum (L. plantarum) content (ng/g feces) in 50 infants each from Colorado (648 samples), Finland (624 samples) and Sweden (685 samples) who participated in the TEDDY (The Environmental Determinants of Diabetes in the Young) study. Total lactobacilli content varied markedly between 5 and 16,800 ng/g feces in the three clinical sites within and between individuals especially in infants. L.plantarum also varied markedly intra- and inter-individually from <0.5 - 736 ng/g feces. A higher variability of total lactobacilli was found before 10 months of age than after in the three different clinical sites. Sweden had the lowest total lactobacilli content compared to Colorado and Finland while the L.plantarum content was higher in Sweden. Mail-in stool samples from infants should prove useful in analyzing probiotics in childhood.

Interaction between CD14-159C>T polymorphism and Helicobacter pylori is associated with serum total immunoglobulin E.

BACKGROUND: Total serum IgE is regulated by both environmental and genetic factors. Association and linkage studies have suggested a role of CD14-159C>T polymorphism in the regulation of serum total IgE, but the results have been contradictory. It seems that gene-environment interactions are involved in this regulation. OBJECTIVE: The aim of this study was to examine the possible gene-environment interactions among Toxoplasma gondii, Helicobacter pylori, CD14-159C>T and Toll-like receptor (TLR) 4+896A>G polymorphism on serum total IgE. For this study, we expanded the scope of our earlier comparison of allergic sensitization and microbial load between Finland and Russian Karelia by studying the CD14-159C>T and TLR4+896A>G polymorphism in a cohort of Russian Karelian children. METHODS: For this study, CD14-159C>T and TLR4+896A>G polymorphisms were analysed in 264 healthy Russian Karelian children. Serum total IgE levels and H. pylori and T. gondii antibodies were also measured. RESULTS: We constructed a multiway anova model to analyse the gene-environment interactions among T. gondii seropositivity, H. pylori seropositivity, CD14-159C>T and TLR4+896A>G polymorphisms on serum total IgE. The model showed that there was an interaction between the CD14-159 allele T carrier status and H. pylori antibodies on serum total IgE (P=0.004). No other interactions were found. CONCLUSION: Our results further emphasize the role of gene-environment interaction in the regulation of serum total IgE.

Analysis of pancreas tissue in a child positive for islet cell antibodies.

AIMS/HYPOTHESIS: Type 1 diabetes is caused by an immune-mediated process, reflected by the appearance of autoantibodies against pancreatic islets in the peripheral circulation. Detection of multiple autoantibodies predicts the development of diabetes, while positivity for a single autoantibody is a poor prognostic marker. The present study assesses whether positivity for a single autoantibody correlates with pathological changes in the pancreas. METHODS: We studied post mortem pancreatic tissue of a child who repeatedly tested positive for islet cell antibodies (ICA) in serial measurements. Paraffin sections were stained with antibodies specific for insulin, glucagon, somatostatin, interferon alpha, CD3, CD68, cyclooxygenase-2 (COX-2), beta-2-microglobulin, coxsackie B and adenovirus receptor (CAR), natural killer and dendritic cells. Apoptosis was detected using Fas-specific antibody and TUNEL assay. Enterovirus was searched for using immunohistochemistry and in situ hybridisation, as well as enterovirus-specific RT-PCR from serum samples. RESULTS: The structure of the pancreas did not differ from normal. The number of beta cells was not reduced and no signs of insulitis were observed. Beta-2-microglobulin and CAR were strongly produced in the islets, but not in the exocrine pancreas. Enterovirus protein was detected selectively in the islets by two enterovirus-specific antibodies, but viral RNA was not found. CONCLUSIONS/INTERPRETATION: These observations suggest that positivity for ICA alone, even when lasting for more than 1 year, is not associated with inflammatory changes in the islets. However, it is most likely that the pancreatic islets were infected by an enterovirus in this child.

Detection of enteroviruses in the intestine of type 1 diabetic patients.

Enterovirus infections have been diagnosed more frequently in type 1 diabetic patients than in the healthy population, and enteroviruses have also been found in the pancreas of diabetic patients. Primary replication of the virus occurs in the gut, but there are no previous studies evaluating possible presence of virus in the intestine of diabetic patients. The purpose of this study was to investigate if enteroviruses can be found in small intestinal tissue of type 1 diabetic patients. Formalin-fixed, paraffin-embedded upper intestinal biopsy samples were analysed for the presence of enterovirus using in situ hybridization and immunohistochemistry. Enterovirus was detected by in situ hybridization in six (50%) of the type 1 diabetic patients (n = 12) but in none of the control subjects (n = 10, P = 0.015). Immunohistochemistry identified enterovirus in nine (75%) of the patients and one (10%) control subject (P = 0.004). The presence of the virus was confirmed by reverse transcription-polymerase chain reaction in one of the four patients from whom a frozen and unfixed sample was available. Intestinal morphology was normal in all study subjects. The results suggest that a substantial proportion of type 1 diabetic patients have an ongoing enterovirus infection in gut mucosa, possibly reflecting persistent enterovirus infection. This observation opens new avenues for further studies on the possible role of enteroviruses in human type 1 diabetes.

Human herpes virus 6 and multiple sclerosis: a Finnish twin study.

OBJECTIVE: To investigate the possible association of human herpes virus 6- (HHV6) infection and multiple sclerosis (MS). BACKGROUND: Despite intensive investigations of genetic and environmental factors, the etiopathogenesis of MS remains unknown. HHV6 is a possible candidate in that it is neurotropic, able to induce demyelination and become latent and be reactivated. We had access to The Finnish National Twin Cohort, which provided a unique opportunity to study the association between HHV6 and MS in genetically homogenous patients. METHODS: Thirty-four serum samples from 17 MS twin pairs and 12 cerebrospinal fluid (CSF) samples from six MS twin pairs were tested by PCR specific for HHV6. Immunoglobulin (Ig) G and M response against HHV6 in serum and CSF were analysed using ELISA method. The samples were collected during a remission of the disease. RESULTS: No HHV6 DNA was found in any serum (n=34) or CSF (n=12) samples. Eighty-eight percent of the twins with MS and 86% of the healthy twin siblings were positive for IgG in serum. One twin with MS was also positive for IgM in serum, whereas none of the healthy twins was IgM positive. All CSF samples were negative for IgG and IgM in both groups. CONCLUSIONS: During a clinical remission of MS the detection of antibodies against HHV6 in CSF and HHV6 DNA in serum, CSF supernatant or CSF leukocytes is unlikely. However, the results do not exclude a possibility of HHV6 reactivation during MS exacerbation or acute HHV6 infection being one of the triggering agents in development of MS long before its clinical manifestation.