Glutamic acid decarboxylase and islet cell antibodies in healthy Estonian children.

The prevalence of antibodies to the 65 kDa isoform of glutamic acid decarboxylase (GADA) was compared with that of islet cell antibodies (ICA) in 614 non-diabetic Estonian children (314 males) aged 3-18 years representing the general population. GADA were analyzed with a radioligand assay, and ICA with a standard immunofluorescence method with a detection limit of 2.5 Juvenile Diabetes Foundation (JDF) units.

Seasonal variation in the incidence of Type 1 diabetes mellitus during 1983 to 1992 in the countries around the Baltic Sea.

Aim: To examine seasonal patterns of incidence of Type 1 diabetes mellitus incidence in children aged 0-14 years in Finland, Sweden, Estonia, Latvia and Lithuania during 1983-1992 (1987-1992 for Finland).

Methods: The study used a method that models incidence data using combinations of sine waves to model seasonal variation around a possible linear trend.

Results: In Finland, a significant pattern was found for combined sexes and age groups 0-9 and 10-14 years.

Distribution of insulin-dependent diabetes mellitus (IDDM)-related HLA alleles correlates with the difference in IDDM incidence in four populations of the Eastern Baltic region.

The high incidence of insulin-dependent diabetes mellitus (IDDM) in Finland contrasts strikingly with the low rates in the neighbouring populations of countries in the Eastern Baltic region: Estonia, Latvia and Russia. To evaluate the possible contribution of genetic factors to these differences, the frequencies of HLA-DQB1 alleles and relevant DQB1-DQA1 or DQB1-DRB1 haplotypes associated with IDDM risk or protection were analysed among IDDM patients and control subjects from these four populations. An increased frequency of HLA-DQB1*0302, DQB1*02-DQA1*05 and DQB1*0302-DRB1*0401 was observed in subjects with IDDM in all studied populations, whereas the prevalence of DQB1*0301 and DQB1*0602 and/or *0603 was decreased among patients.

The effect of HLA-B allele on the IDDM risk defined by DRB1*04 subtypes and DQB1*0302.

The genes encoding the HLA-DQ heterodimer molecules, DQB1 and DQA1, have been found to have the strongest association with IDDM risk, although there is cumulative evidence for the effect of other gene loci within the major histocompatibility complex gene region. After the HLA-DQ locus, the HLA-DR locus has been suggested most often as contributing to the disease susceptibility. In this study we analyzed at the population level the effect of DR4 subtypes and class I, HLA-B alleles, on IDDM risk when the influence of the DQ locus was stratified.

HLA-DQB1*0304-DRB1*0408 haplotype associated with insulin-dependent diabetes mellitus in populations in the eastern Baltic region.

The rare HLA-DQB1*0304 allele was found increased among IDDM patients in the populations of the eastern Baltic region. Its frequency among IDDM patients was 4.5% (20/443) compared to 1.