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J Ilonen

Publications and source records attributed to J Ilonen.

At least 55 records · Page 3Linked to original sources

Responses of coxsackievirus B4-specific T-cell lines to 2C protein-characterization of epitopes with special reference to the GAD65 homology region.

Coxsackie B viruses (CBV) have been indicated as environmental triggers initiating autoimmune destruction of insulin-producing pancreatic beta-cells, and molecular mimicry might be the mechanism. A prime candidate for inducing cross-reactive immune responses is a homology sequence, PEVKEK, found both in CBV4 2C protein and in GAD65. To characterize the CBV4-specific T-cell epitopes, overlapping peptides covering the 2C protein were synthesized and CBV4-specific T-cell lines were established from healthy and diabetic subjects. The T-cell epitopes were dependent on the HLA-DR genotype of the T-cell donor, but no difference between diabetic and healthy subjects could be detected. Peptide p4, which included the PEVKEK sequence, contained an HLA-DR1-restricted T-cell epitope. Three randomly selected CBV4-specific T-cell lines, which responded to peptide p4, failed to recognize GAD65 protein or GAD65 peptides containing the PEVKEK sequence. We conclude that the CBV4 2C protein is strongly immunogenic for T-cells and PEVKEK is included in a T-cell epitope. However, presentation of this epitope in the context of neutral HLA-DR1 allele does not support its role in pathogenesis of type 1 diabetes.

Adult↗

Cell membrane-associated measles virus components inhibit antigen processing.

Measles virus (MV)-induced immune suppression is an important reason for MV-associated mortality and morbidity. Despite numerous studies, the mechanisms of immune suppression still remain poorly defined. In the present study we analyzed the effect of MV components on the T-cell recognition of specific non-MV antigens. We demonstrated that even inactivated MV could inhibit the presentation of unprocessed protein antigen to specific T cells, whereas MV did not affect the responses of specific T cells to representative synthetic peptide epitopes derived from complex antigens. The inhibition was induced by MV-infected cell membranes. The kinetics of the MV-dependent inhibition suggested an impaired antigen processing in mononuclear cells as addition of MV-infected cell debris 4 h after the beginning of cell cultures no longer inhibited T-cell responsiveness.

Antigen Presentation↗

HLA haplotype analysis in Finnish patients with rheumatoid arthritis.

OBJECTIVE: To further characterize the HLA gene products that play an important role in the pathogenesis of rheumatoid arthritis (RA). METHODS: One hundred thirty-four haplotypes from 67 Finnish RA patients and 77 control haplotypes were analyzed for HLA-DRB1 loci, associated alleles of the HLA-DQB1 locus, alleles of the type 2 transporter-associated antigen processing (TAP2) genes, and HLA-B27. In addition, a panel of microsatellite markers within the HLA class I and class III regions was studied. RESULTS: The frequency of HLA-DRB1*04 in the haplotypes of RA patients was found to be 34% (45 of 134) compared with 14% (10 of 72) in control haplotypes (P = 0.004). The frequency of HLA-DRB1*13 was decreased in RA haplotypes (4%, or 5 of 134) in contrast to control haplotypes (24%, or 17 of 72) (P = 0.000031). The decrease in DRB1*13 was not secondary to the increase in DRB1*04, since it was also found among DRB1*04-negative haplotypes (P < 0.001). The DRB1*13-associated DQB1*0604 allele was similarly decreased in RA haplotypes (P = 0.025). The TAP2I allele of I/J dimorphism was increased in RA patients (85%, or 114 of 134) as compared with controls (69%, or 49 of 71) (P = 0.011). Of the tumor necrosis factor (TNF) microsatellite alleles, TNFa6 and TNFb5 were found to be increased in RA haplotypes (for a6 27% versus 5% in controls [P = 0.00043], and for b5 43% versus 26% in controls [P = 0.037]). CONCLUSION: Both protection-associated and susceptibility-associated alleles can be found among HLA class II genes, and the results suggest that loci outside DR/DQ may contribute to the pathogenesis of RA.

Arthritis, Rheumatoid↗

Short-term exclusive breastfeeding predisposes young children with increased genetic risk of Type I diabetes to progressive beta-cell autoimmunity.

AIMS/HYPOTHESIS: This study aimed to establish the relation between early infant nutrition and signs of beta-cell autoimmunity in young children. METHODS: We identified and observed from birth 2949 infants with increased genetic risk of Type I (insulin-dependent) diabetes mellitus (HLA DQB1*02/ *0302 or DQB1*0302/x, x = other than *02, *0301 or *0602) and monitored them for islet cell antibodies at 3 to 6 month intervals. If an infant seroconverted to islet cell antibody positivity, all of his or her samples were also analysed for autoantibodies to insulin, GAD65 (GADA) and to the protein tyrosine phosphatase related IA-2 molecule (IA-2A). Our case-control study comprises the first 65 children who seroconverted to islet cell antibody positivity before the age of 4 years and 390 control children who were islet cell antibody-negative (six control children/ case). We monitored the duration of exclusive and total breastfeeding and the age at which cows' milk was introduced. RESULTS: Infants who had been breastfed exclusively for at least 4 months had lower risk of seroconversion to positivity for IA-2A or all four autoantibodies [odds ratio (OR) 0.24; 95 % CI 0.06-0.94 and OR 0.17; 95 % CI 0.03-0.86, respectively] than those infants who had been breastfed exclusively for less than 2 months. The risk of seroconversion to positivity for IA-2A or all four autoantibodies was higher in those younger than 2 months (OR 4.37; 95 % CI 1.33-14.42 and OR 5.02; 95 % CI 1.27-19.89) or aged 2 to 3.9 months (OR 5.50; 95 % CI 1.21-25.04 and 6.19; 95% CI 1.10-34.84) when they first received cows' milk than in those aged 4 months or older. CONCLUSIONS/INTERPRETATION: These observations suggest that short-term breastfeeding and the early introduction of cows' milk-based infant formula predispose young children who are genetically susceptible to Type I diabetes to progressive signs of beta-cell autoimmunity.

Aging↗

Feasibility of genetic and immunological prediction of type I diabetes in a population-based birth cohort.

AIMS/HYPOTHESIS: Population-wide genetic screening of susceptibility to multifactorial diseases will become relevant as knowledge of the pathogenesis of these diseases increases and preventive interventions are identified. METHODS: Feasibility and acceptance of neonatal genetic screening for Type I (insulin-dependent) diabetes mellitus susceptibility and adherence of the at-risk children to frequent autoantibody follow-up were studied. Screening was offered to all families. The infants with HLA-DQB1 genotypes *02/*0302 and *0302/x (x not equal to *02, *0301, *0602) were invited to autoantibody follow-up. The children who developed signs of beta-cell autoimmunity were invited to a separate prevention trial. RESULTS: The parents of 31,526 babies born between November 1994 and April 1999 (94.4% of those eligible) agreed to genetic screening. We found that 4651 infants (14.8%) had increased genetic risk (2.5 to 15 times that of the general population) for Type I (insulin-dependent) diabetes mellitus, and 80% of them joined the autoantibody surveillance. At the age of 1, 2, 3 and 4 years, 74, 69, 68 and 76% of the at-risk children, respectively, attended the follow-up. A total of 17 of the 22 children (77%) who were born during the study period and have developed diabetes carry the risk genotypes we currently use for screening. CONCLUSIONS/INTERPRETATION: Population-based screening of genetic susceptibility for Type I diabetes, linked with a possibility to participate later in a prevention trial, is highly accepted in Finland and identifies about 75% of those developing diabetes at an early age. Families adhere well to the frequent measurement of signs of beta-cell autoimmunity in the children at-risk.

Alleles↗

Enterovirus antibody levels during the first two years of life in prediabetic autoantibody-positive children.

AIMS/HYPOTHESIS: We evaluated the role of enterovirus infections in the pathogenesis of Type I (insulin-dependent) diabetes mellitus by monitoring enterovirus antibody levels in prediabetic children who turned positive for diabetes-associated autoantibodies in a prospective birth cohort study. METHODS: Serial serum samples taken during prospective observation starting at birth were analysed for IgG and IgA class antibodies against enterovirus antigens including purified coxsackievirus B4, echovirus 11, poliovirus 1 and a synthetic enterovirus peptide antigen using enzyme immunoassay. Maternal samples taken at the end of the third month of pregnancy were also studied. Analyses were done from 21 childen who developed autoantibodies and from 104 autoantibody-negative control children who were matched for the time of birth, gender and HLA susceptibility alleles. For comparison, adenovirus antibodies were also analysed from all samples collected. RESULTS: IgG class enterovirus antibody levels were high in maternal samples and in cord blood in both case and control children. After birth the IgG levels decreased reaching a nadir at the age of 6 months. No IgA class antibodies were detected at birth but started to emerge postnatally. Antibody levels did not differ between the autoantibody positive and the control children during the first 6 months of life. From 6 months to 24 months of age, the autoantibody positive children had higher IgG and IgA levels against coxsackievirus B4, echovirus 11 and the synthetic enterovirus peptide antigens than control children but poliovirus 1 and adenovirus antibodies were closely similar in the two groups. The difference between children with autoantibodies and control children was predominantly seen among boys and among those with the HLA-DQB1*0302/x genotype. CONCLUSIONS/INTERPRETATION: Our data show that children who seroconverted for diabetes-associated auto-antibodies develop stronger humoral immune responses to coxsackievirus B4, echovirus 11 and a synthetic enterovirus peptide antigen than children who remained negative for autoantibodies. Poliovirus antibodies induced by uniform vaccinations did not differ between the prediabetic and control children suggesting that the regulation of antibody responses to enteroviruses is not disturbed. Accordingly, the results imply a stronger enterovirus exposure in prediabetic children supporting the role of enteroviruses in the pathogenesis of Type I diabetes.

Antibodies, Viral↗

Prevalence of coeliac disease in siblings of patients with Type I diabetes is related to the prevalence of DQB1*02 allele.

AIMS/HYPOTHESIS: Coeliac disease is more prevalent among patients with Type I (insulin-dependent) diabetes mellitus and coeliac disease-related antibodies have been reported to increase in frequency in their first-degree relatives. Our aim was to find out if coeliac disease is more common among siblings of children with Type I diabetes than in the normal population. METHODS: IgA endomysium antibodies were measured by indirect immunofluorescence in 550 subjects (mean age 11.8 years, range 3.1-26.9 years) with a sibling with Type I diabetes. We performed jejunal biopsy on as many subjects with positive antibodies as agreed. HLA-DQB1 genotyping was done in 427 subjects. RESULTS: Endomysium antibodies were positive in nine subjects (1.6 %). Jejunal biopsy was diagnostic for coeliac disease in five out of seven patients. An additional patient with coeliac disease, one already on a gluten-free diet, was identified by questionnaire. The prevalence of coeliac disease was 1.1 %. Five of six patients with coeliac disease had HLA-DQB1*02 allele, compared with 118 of 421 of those without coeliac disease (p = 0.009). The sixth patient was positive for HLA-DQB1*0302 allele, which was also found in 241 of 421 of those without coeliac disease (p = 0.4). CONCLUSION/INTERPRETATION: We found the prevalence of coeliac disease among siblings of children with Type I diabetes to be similar to figures reported from recent population-based studies and to be correlated with the prevalence of coeliac disease associated HLA-DQB1 alleles. We propose that routine screening for coeliac disease among all first-degree relatives of patients with Type I diabetes is not warranted.

Adolescent↗

Cytokine expression in unstimulated PBMC of children with type 1 diabetes and subjects positive for diabetes-associated autoantibodies.

The aim of this study was to evaluate possible changes in the circulating levels of interferon (IFN)-gamma, interleukin (IL)-4 and transforming growth factor (TGF)-beta in association with the autoimmune process leading to type 1 diabetes. Expression levels of mRNAs specific for each cytokine were determined in peripheral blood mononuclear cells (PBMC) by a multiplex reverse transcription-polymerase chain reaction (RT-PCR) followed by hybridization reactions with lanthanide-labelled probes and detection by time-resolved fluorometry. Newly diagnosed diabetic children had lower levels of IFN-gamma, IL-4 and TGF-beta 1 signals compared to their age- and sex-matched controls (P < 0.02, P < 0.005 and P < 0.005, respectively) and also the autoantibody-positive subjects had significantly lower levels of IL-4 and TGF-beta 1 in comparison with their matched controls (P = 0.0013 and P = 0.012). No significant differences were observed when comparing matched pairs of diabetic children and autoantibody-positive subjects. Our results suggest a systemic bias towards reduced production of T-helper cell type 2 cytokines (IL-4 and TGF-beta 1) during the autoimmune process, but there was also a reduced level of IFN-gamma expression in the periphery at the onset of clinical diabetes.

Autoantibodies↗

No evidence of abnormal regulation of antibody response to coxsackievirus B4 antigen in prediabetic children.

Enterovirus infections are a potential environmental trigger of the autoimmune process leading to clinical type 1 diabetes. It has been suggested that the risk of virus-induced beta-cell damage might be connected with a defect in humoral immune responsiveness to enteroviruses. In the present study we assessed whether such a defect in IgG responsiveness to coxsackievirus B4 antigen existed in young children who developed diabetes-associated autoantibodies during prospective observation from birth until the age of 18 months. IgG levels and maturation of antibody avidity were analysed in 21 children with autoantibodies and 41 control children who had experienced an equal number of enterovirus infections and were additionally matched for age, sex and HLA-DQB1 risk alleles for type 1 diabetes but had not produced diabetes-associated autoantibodies. IgG levels to coxsackievirus B4 were high in cord serum reflecting the presence of maternal antibodies. Mean IgG levels gradually decreased but began to increase after the age of 6 months, showing no significant difference between autoantibody positive and control children. The avidity of antibodies was strong in cord serum and decreased gradually during the first year of life when maternal antibodies disappeared. The avidity indices, which varied considerably from child to child, did not differ between the autoantibody-positive and -negative subjects. In conclusion, our data suggest that children affected by a beta-cell damaging autoimmune process show normal responses to coxsackievirus B4 antigens.

Antibodies, Viral↗

Differences between female and male patients with familial rheumatoid arthritis.

OBJECTIVE: To determine whether there are genetic differences between female and male patients with familial rheumatoid arthritis (RA). METHODS: 45 men and 119 women from 78 families with RA who all had at least one first degree relative with RA were compared. HLA-DRB1 alleles were analysed, including DRB1*04 subtypes and associations of DRB1*04 haplotypes with DQB1*0301 or DQB1*0302 alleles, the age of the patients at disease onset, the presence of rheumatoid factor (RF), joint erosions, and rheumatoid nodules. RESULTS: HLA-DRB1*13 allele (the subtype allele of DR6, reported to be protective against the development of RA) was found in 14/119 (12%) of female but in none of the male patients (p=0.036). The HLA-DR4 allele was found slightly more often in men than women patients with familial RA (31/45 (69%) v 75/119 (63%), NS). Men were also more often RF positive than women (44/45 (98%) v 98/117 (84%); p=0.031). On the other hand, the mean age at onset of RA was significantly lower in the female group (40.4 years) than in men (46.6 years, p=0.0044). CONCLUSION: The results indicate that there is stronger genetic background in familial male than female patients with RA in the genetic susceptibility defined by the studied HLA antigens. However, the earlier age of onset of the disease in female group and the increased proportion of women with RA indicate that there are additional sex related predisposing factors enhanced in familial cases.

Adult↗

The first signs of beta-cell autoimmunity appear in infancy in genetically susceptible children from the general population: the Finnish Type 1 Diabetes Prediction and Prevention Study.

Little is known about the timing of the etiological events and the preclinical process of type 1 diabetes during the first years of life in the general population. In this population-based prospective birth cohort study, the appearance of diabetes-associated autoantibodies as a sign of beta-cell autoimmunity and the development of type 1 diabetes were monitored from birth. Of 25,983 newborn infants, 2,448 genetically susceptible children were monitored for islet cell antibodies (ICA) at 3- to 6-month intervals. If an infant seroconverted to ICA positivity, all his/her samples were also analyzed for insulin autoantibodies (IAA), antibodies to the 65-kDa isoform of glutamic acid decarboxylase, and antibodies to the protein tyrosine phosphatase-related IA-2 molecule. Fifteen children of those who carried the high-risk genotype (2.7%) and 23 of those who carried the moderate-risk genotype (1.2%; P = 0.019) tested positive for ICA at least once. Among those who showed positivity for at least 2 antibodies during the observation period (25 of 38), IAA appeared as the first or among the first antibodies in 22 children (88%) and emerged earlier than the other antibodies (P < 0.019 or less). The first autoantibodies appeared in the majority of the children in the fall and winter (30 of 38 vs. 8 of 38 in the spring and summer, P < 0.001). These observations suggest that young children in the general population with a strong human-leukocyte-antigen-DQ-defined genetic risk of type 1 diabetes show signs of beta-cell autoimmunity proportionally more often than those with a moderate genetic risk. IAA emerge as the first detectable antibody more commonly than any other antibody specificity, implying that insulin may be the primary antigen in most cases of human type 1 diabetes associated with the DR4-DQB1*0302 haplotype. The seasonal variation in the emergence of the first signs of beta-cell autoimmunity suggests that infectious agents may play a role in the induction of such autoimmunity.

Autoantibodies↗

Induction of interferon-gamma and IL-4 production by mitogen and specific antigens in peripheral blood lymphocytes of Type 1 diabetes patients.

A functional imbalance in cytokine production resulting in dominance of Th1 over Th2 type response has been suggested to play a critical role in the pathogenesis of type 1 diabetes. In this study the cellular responses to pokeweed mitogen and a panel of specific antigens were analysed by measuring the production of IFN-gamma and IL-4 cytokines at the levels of mRNA expression (expression index=antigen/medium) and protein secretion in culture supernatants. Two enterovirus preparates were included due to the suggested significance of these viruses in the aetiology of type 1 diabetes. The study included 22 children with newly-diagnosed type 1 diabetes, 15 children with longer duration of disease and 20 healthy children. Comparisons were made between age- and sex-matched groups. Newly diagnosed diabetic patients had significantly higher IFN-gamma mRNA expression index (p<0.02) but also higher IL-4 mRNA expression index (p<0.05) in tetanus toxoid stimulated peripheral blood mononuclear cells compared to healthy controls. Also the diabetic patients studied 3-72 months after the diagnosis of type 1 diabetes showed a tendency to higher IFN-gamma mRNA expression index compared to controls (0.05<p<0.1). Enhanced mitogen-stimulated IFN-gamma mRNA expression index was observed in children with newly-diagnosed type 1 diabetes when compared to subjects with longer duration of diabetes (p<0.05). No significant differences were observed in IFN-gamma produced into the culture supernatants. In conclusion, imbalance in both IFN-gamma and IL-4 mRNA levels was demonstrated between diabetic patients and healthy subjects.

Adolescent↗

Solid-phase PCR with hybridization and time-resolved fluorometry for detection of HLA-B27.

BACKGROUND: Preactivated solid surfaces provide new possibilities for multiple consecutive reactions in a microtiter plate format. In this study, a combination of PCR and subsequent hybridization in the same microtiter well was applied for the detection of HLA-B27 alleles. METHODS: A multiplex solid-phase PCR to amplify the HLA-B27 alleles together with beta-actin as an amplification control gene was performed on the NucleoLink (Nunc) surface. PCR was followed by hybridization and detection with time-resolved fluorescence. For the covalent capture of the PCR primers onto the solid support via a 1-(3-dimethylamino-propyl)-3-ethylcarbodiimide hydrochloride-mediated reaction, different 5'-end modifications of oligonucleotides were tested [amination, phosphorylation, and a poly(dT)10 linker]. RESULTS: For covalent immobilization of the primers, amination of the 5' end combined with use of the poly(dT)10 linker was superior. At least 19.5% of the primer added per well was attached via a stable bond. When the standard time-resolved, fluorescence-based HLA-B27 detection system was compared with the newly developed method in a sample series of 82 genomic DNAs and the corresponding dried-blood spots, all results were in full agreement. CONCLUSIONS: The new solid-phase PCR approach can be applied for multiple-target DNA detection. PCR followed by hybridization can be accomplished in a few hours using precoated strips and dried-blood spot PCR templates.

5' Untranslated Regions↗

Novel fusion proteins in the analysis of diabetes-associated autoantibodies to GAD65 and IA-2.

Assays to detect autoantibodies to glutamic acid decarboxylase (GAD65) and the protein tyrosine phosphatase-like molecule IA-2, which are both present in pancreatic islets, have been used in the diagnosis and prediction of type 1 diabetes. In this study a novel fusion protein combining the entire GAD65 molecule with the 40 kDa intracellular domain of IA-2 (GAD-IA-2) was constructed to detect autoantibodies to both antigens by one single assay. For the same purpose a truncated version of this fusion protein which contained the entire GAD65 linked to the 203 carboxy-terminal amino acids of IA-2 (GAD-dIA-2) was made. A panel of 34 diabetic sera which represented unequivocally positive or negative antibody responses to GAD65 and/or IA-2 as well as 20 serum samples from healthy controls were tested in a radioligand binding assay with the constructed fusion proteins as antigens. Nine of the samples from patients with type 1 diabetes reacted with GAD65 while being negative for IA-2. Six sera were positive for IA-2 only, 11 were double positive, and 8 negative for both antibodies using the standard in vitro transcription translation assay with single antigens. The full-length, as well as the truncated fusion protein detected all samples positive for antibodies either to GAD65 or IA-2 or both, except for one GAD65 antibody positive sample. All samples from healthy controls tested negative in all assays. We conclude that the principle of a combinatorial molecule where a fusion protein expresses both GAD65 and IA-2 epitopes is feasible, and such a fusion protein can be used instead of the single antigens to reduce time and costs of large-scale screening for clinical purposes.

Adolescent↗

Stability of autoantibodies and their relation to genetic and metabolic markers of Type I diabetes in initially unaffected schoolchildren.

AIMS/HYPOTHESIS: To study temporal changes in positivity for autoantibodies associated with Type I (insulin-dependent) diabetes mellitus and the relations between these antibodies, HLA-DQB1-risk markers and first-phase insulin response (FPIR) in non-diabetic schoolchildren. METHODS: The stability of the antibody status over 2 years was assessed in 104 schoolchildren initially positive for islet cell antibodies (ICA) or antibodies to the 65,000 M(r) isoform of the glutamic acid decarboxylase (GADA) or both and in 104 antibody-negative control children matched for sex, age and place of residence. All children were also studied for their first-phase insulin response and HLA-DQB1 alleles on the second occasion. RESULTS: On the second occasion 3 of the 98 initially ICA-positive children, 3/13 of those positive for antibodies to the IA-2 protein (IA-2A), 1/17 GADA-positive and 2/7 of those positive for insulin autoantibodies (IAA) tested negative for these antibodies. Children with IA-2A, GADA, IAA and multiple (> or = 2) antibodies had significantly lower first-phase insulin responses than the control children. In contrast, these responses did not differ between subjects with and without specific HLA-DQB1-risk alleles or genotypes. Of the six subjects with a considerably reduced first-phase insulin response three had multiple antibodies on both occasions but none of them had a DQB1 genotype conferring increased diabetes risk. Two subjects progressed to Type I diabetes within 3.4 years of follow-up, both of them having multiple antibodies and a considerably reduced first-phase insulin response but neither of them having a DQB1-risk genotype. CONCLUSIONS/INTERPRETATION: Positivity for diabetes-associated autoantibodies is a relatively stable phenomenon in unaffected schoolchildren, although conversion to seronegativity can occur occasionally. Our observations also indicate that DQB1 alleles associated with decreased susceptibility to Type I diabetes do not protect from impaired beta-cell function or from progression to overt disease in initially unaffected schoolchildren.

Adolescent↗

Impaired insulin secretion in non-diabetic offspring of probands with latent autoimmune diabetes mellitus in adults.

AIMS/HYPOTHESIS: This study was undertaken to investigate metabolic and genetic characteristics of latent autoimmune diabetes in adults (LADA). METHODS: We evaluated insulin secretory capacity with oral and intravenous glucose tolerance tests (early insulin response) and hyperglycaemic clamp (insulin secretory capacity) and the rates of whole body glucose uptake with the euglycaemic clamp, HLA-DQB1 genotypes (time-resolved fluorescence) and islet cell antibodies (ICA) (immunofluorescence) and antibodies to glutamic acid decarboxylase (GAD) (radio-immunoprecipitation) in 36 non-diabetic offspring (LADA-offspring) of patients with Type II (non-insulin-dependent) diabetes mellitus who tested positive for ICA and/or GAD antibodies during the 10-year follow-up from the diagnosis and in 19 healthy control subjects without a family history of diabetes. RESULTS: The early insulin response during the first 10 min of an intravenous glucose tolerance test was about 40% lower in the LADA-offspring than in the control group (p = 0.008). Insulin secretory capacity in the hyperglycaemic clamp was also about 30% lower in the LADA-offspring (p = 0.048). The rates of whole body glucose uptake were similar in both groups. The frequency of low risk HLA-DQB1 genotypes was higher in the LADA-offspring than among Finnish healthy blood donors (p = 0.033). The risk conferring genotypes were associated with the lowest tertile of insulin secretory capacity in the LADA-offspring (p = 0.032). There were no associations between the autoantibodies and early insulin response or insulin secretory capacity within the study groups. CONCLUSION/INTERPRETATION: We conclude that LADA is a familial disease involving most likely gene defects leading to a slow progressive beta-cell destruction and insulin deficiency.

Adipose Tissue↗

Intercellular adhesion molecule-1 (ICAM-1) K469E polymorphism: no association with type 1 diabetes among Finns.

The intercellular adhesion molecule-1 (ICAM-1) has an important role in the process of lymphocyte migration and activation, and is supposed to be involved in the pathogenesis of type 1 diabetes. We studied A/G (K469E) polymorphism of the ICAM-1 gene in 218 type 1 diabetes patients and 212 controls from Finland and found no association. We then studied transmission of the ICAM-1 alleles in 102 Finnish families using a transmission disequilibrium test (TDT). Alleles A and G were transmitted to the affected offspring in 50% each. Stratification by the HLA-DQB1-DQA1 genotypes, sex and age at onset did not reveal association. Our data demonstrate that in the Finnish population K469E polymorphism of the ICAM-1 gene is not associated with type 1 diabetes.

Adolescent↗