Fluctuations in GAD65 antibodies after clinical diagnosis of IDDM in young children.
OBJECTIVE
To investigate whether the presence of GAD antibodies at onset of IDDM correlates to a more aggressive rate of beta-cell destruction after clinical onset.


METHODS
We studied GAD antibodies at onset of disease, after 1 year, and after 6 years in 33 consecutively referred children (mean age 8.08, range 1.7-16.3). In a subset of 11 patients, GAD antibodies were studied very frequently. The correlation between GAD antibodies and clinical parameters, including glycosylated hemoglobin, residual insulin secretion, and insulin dosage, was evaluated.


RESULTS
GAD antibody titers were highly variable. Four patients became GAD antibody positive weeks to years after clinical onset. Other patients switched between testing positive and negative for GAD antibodies shortly after clinical onset. No correlation was found between the presence of GAD antibodies and the rate of beta-cell destruction, but patients with high GAD antibody indexes at onset had significantly higher glycosylated hemoglobin levels.


CONCLUSIONS
GAD antibodies at clinical onset do not predict the rate of beta-cell destruction in young children with newly diagnosed IDDM. The highly variable GAD antibody levels suggest variation of the autoimmune process.
Batstra
M R
MR
Department of Pediatrics, Sophia Children's Hospital, Rotterdam, The Netherlands.
Pina
M
M
Quan
J
J
Mulder
P
P
de Beaufort
C E
CE
Bruining
G J
GJ
Aanstoot
H J
HJ
D001323:Autoantibodies / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002096:C-Peptide / Q000097:blood; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000188:drug therapy / Q000276:immunology*; D005500:Follow-Up Studies; D005969:Glutamate Dehydrogenase / Q000276:immunology*; D006801:Humans; D007223:Infant; D007332:Insulin Infusion Systems; D008137:Longitudinal Studies; D013997:Time Factors
D001323:Autoantibodies; D015415:Biomarkers; D002096:C-Peptide; D005969:Glutamate Dehydrogenase