Proficiency Testing of Human Leukocyte Antigen-DR and Human Leukocyte Antigen-DQ Genetic Risk Assessment for Type 1 Diabetes Using Dried Blood Spots

Background:The plurality of genetic risk for developing type 1 diabetes mellitus (T1DM) lies within the genes that code for the human leukocyte antigens (HLAs). Many T1DM studies use HLA genetic risk assessment to identify higher risk individuals, and they often conduct these tests on dried blood spots (DBSs) like those used for newborn bloodspot screening. One such study is The Environmental Determinants of Diabetes in the Young (TEDDY), a long-term prospective study of environmental risk factors. To provide quality assurance for T1DM studies that employ HLA genetic risk assessment, the Centers for Disease Control and Prevention (CDC) conducts both a voluntary quarterly Proficiency testing (VQPT) program available to any laboratory and a mandatory annual Proficiency testing (PT) challenge for TEDDY laboratories.Methods:Whole blood and DBS samples with a wide range of validated HLA-DR and HLA-DQ genotypes were sent to the participating laboratories. Results were evaluated on the basis of both the reported...