[Diagnostic efficacy of glutamic acid decarboxylase antibody and islet cell antibody in type I diabetes mellitus].
OBJECTIVE
To investigate the diagnostic efficacy of glutamic acid decarboxylase antibody (GAD65-Ab) and islet cell antibody (ICA) in type I diabetes mellitus.


METHODS
104 cases of type I diabetes mellitus and 102 normal controls were recruited, GAD65-Ab was determined with radioligand assay and ICA with ELISA. The diagnostic efficacy of GAD65-Ab and ICA was analysed by receiver-operating characteristic (ROC) curve with sensitivity, specificity and curve area.


RESULTS
(1) The optimal cut-off point of GAD65-Ab was at 0.30, while that of ICA was at 0.45. The area under the curve of GAD65-Ab and ICA were 0.835 and 0.715 respectively. Compared with 0.5, the area under curve of GAD65-Ab and ICA was higher (P < 0.0001). The area under curve of GAD65-Ab was higher than that of ICA(P < 0.01). (2) In type I diabetes mellitus patients, the positivity of GAD65-Ab was not correlated to the age of onset and duration of the disease, while the positivity of ICA was correlated to the age of onset and duration.


CONCLUSIONS
Type I diabetes mellitus can be diagnosed with GAD65-Ab and ICA. The diagnostic efficacy of GAD65-Ab is higher than that of ICA. In patients of type I diabetes mellitus with adult-onset and duration more than one year, the diagnostic efficacy of GAD65-Ab is higher than that of ICA, while in patients of type I diabetes mellitus with adolescent-onset and duration less than one year, the diagnostic efficacy of ICA is higher than that of GAD65-Ab.
Ouyang
L
L
Department of Endocrinology, First Affiliated Hospital, Guangxi Medical University, Nanning 530021, China.
Wang
J
J
Zhu
X
X
D000293:Adolescent; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis*; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve
D001323:Autoantibodies; C024211:islet cell antibody; D005968:Glutamate Decarboxylase