Capillary whole blood measurement of islet autoantibodies

OBJECTIVE - Islet cell antibody (ICA) measurements in serum are used for la rge-scale screening to identify subjects who are at high risk of developing type 1 diabetes. The aim of this study was to adapt measurements to capill ary whole blood samples to facilitate and reduce screening costs. RESEARCH DESIGN IND METHODS - GAD65, IA-2, and combined GAD65/IA-2 antibody tests were performed on patients with type 1 diabetes, first-degree relati ves of patients, and control subjects, and results from serum, plasma, whol e venous blood, and capillary whole blood lysates were compared. Measuremen ts obtained in serum and eluates from dried capillary blood spots from 36 I CA(+) first-degree relatives were also compared. RESULTS - GAD65, IA-2, and combined GAD65/IA-2 antibody levels were complet ely concordant with measurements obtained from serum, plasma, whole venous blood, and capillary whole blood lysates. Antibody levels obtained in eluat es from dried capillary blood spots were lower than corresponding serum sam ples, and weak antibodies were not detected. CONCLUSIONS - Initial screening for diabetes risk can be performed using on e drop of capillary whole blood without further processing to separate seru m. This method should be considered as a way to simplify and reduce costs o f screening programs.