Capillary whole blood measurement of islet autoantibodies.
OBJECTIVE
Islet cell antibody (ICA) measurements in serum are used for large-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 capillary whole blood samples to facilitate and reduce screening costs.


METHODS
GAD65, IA-2, and combined GAD65/IA-2 antibody tests were performed on patients with type 1 diabetes, first-degree relatives of patients, and control subjects, and results from serum, plasma, whole venous blood, and capillary whole blood lysates were compared. Measurements obtained in serum and eluates from dried capillary blood spots from 36 ICA+ first-degree relatives were also compared.


RESULTS
GAD65, IA-2, and combined GAD65/IA-2 antibody levels were completely concordant with measurements obtained from serum, plasma, whole venous blood, and capillary whole blood lysates. Antibody levels obtained in eluates from dried capillary blood spots were lower than corresponding serum samples, and weak antibodies were not detected.


CONCLUSIONS
Initial screening for diabetes risk can be performed using one drop of capillary whole blood without further processing to separate serum. This method should be considered as a way to simplify and reduce costs of screening programs.
Bazzigaluppi
E
E
Department of Medicine, Istituto Scientifico San Raffaele, Milan, Italy.
Bonfanti
R
R
Bingley
P J
PJ
Bosi
E
E
Bonifacio
E
E
D001323:Autoantibodies / Q000097:blood*; D001800:Blood Specimen Collection / Q000379:methods; D002196:Capillaries; D002648:Child; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000235:genetics* / Q000276:immunology*; D005190:Family; D005968:Glutamate Decarboxylase / Q000276:immunology; D006801:Humans; D007515:Islets of Langerhans / Q000276:immunology; D012016:Reference Values; D012044:Regression Analysis
D001323:Autoantibodies; C024211:islet cell antibody; D005968:Glutamate Decarboxylase