Many international studies are currently looking for ways to reverse or slow the pathogenesis of type 1 diabetes. Interest is especially focused on changing the diet of infants who are found at risk. Efforts to develop screening methods for type 1 diabetes run in parallel to this work. It is important that when improved treatment for type 1 diabetes becomes available, the means of identifying high risk subjects is also in place.

Autoantibodies such as GAD65, IA-2 and IAA have shown to be truly predictive for type 1 diabetes. However as a method of screening their use alone is impractical. It would be both time-consuming and expensive to work with blood samples taken at regular intervals up to adolescence from all apparently healthy young children. The autoantibody tests will therefore be more suitable for use in conjunction with genetic screening tests that will first detect those children who are most at risk and who could most benefit from autoantibody monitoring. Genetic screening using DNA probe assays will be able to reduce the number of children to be followed down to 5 to 15 % of the whole copulation.

PerkinElmer probes specific for various HLA and non–HLA alleles are currently used for research to discover the genes involved in conferring a genetic risk of, or protection from developing type 1 diabetes. The HLA markers comprise DQB1, DQA1 and DRB1. In addition, non HLA markers, CTLA-4 and insulin gene polymorphisms have been associated with susceptibility to Type 1 Diabetes. Once the DNA in a blood sample is amplified, the presence of the particular alleles is determined by a hybridization reaction using allele-specific, short oligonucleotides labelled with lanthanide chelates. Employing the same sensitive DELFIA® technology as PerkinElmer’s serology tests, the probe assays are less technically demanding than traditional solutions and support large sample volume throughput, enabling quicker, more effective research.

In the future it is hoped that tests such as PerkinElmer’s probe assays will become available for diagnostic use. Children discovered to be carrying the alleles known to be associated with risk can then be monitored for the presence of the autoantibodies every three months during their first two years and then every six months up to the age of 15 years. Often insulin autoantibodies (IAA) are the first markers to appear and they are present in the vast majority of young children destined to develop type 1 diabetes. It has been shown that better predictive value is obtained if there are two or more different autoantibodies circulating in the blood.

PerkinElmer autoantibody kits, currently available as research products, include DELFIA GAD65 Ab, DELFIA IA-2 Ab and DELFIA IAA. The assays provide an easy-to-perform, non-isotopic method for quantification of the autoantibodies in serum samples.

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