AUTOANTIBODIES TO GLUTAMIC-ACID DECARBOXYLASE AND INSULIN IN ISLET-CELL ANTIBODY-POSITIVE PRESYMPTOMATIC TYPE-1 DIABETES-MELLITUS - FREQUENCY AND SEGREGATION BY AGE AND GENDER
Pz. Zimmet et al., AUTOANTIBODIES TO GLUTAMIC-ACID DECARBOXYLASE AND INSULIN IN ISLET-CELL ANTIBODY-POSITIVE PRESYMPTOMATIC TYPE-1 DIABETES-MELLITUS - FREQUENCY AND SEGREGATION BY AGE AND GENDER, Diabetic medicine, 11(9), 1994, pp. 866-871
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Categorie Soggetti
Endocrynology & Metabolism","Medicine, General & Internal
The frequency of antibodies to glutamic acid decarboxylase (GAD) and i
nsulin (IAA) in presymptomatic Type 1 diabetes mellitus with a positiv
e test for antibodies to islet cell antigen (ICA) was examined. Thirty
-two persons positive for ICA (> 10 JDF units) were tested 2 to 48 mon
ths before their ascertained onset of Type 1 diabetes. ICA was quantit
ated by immunofluorescence as JDF units, anti-GAD by radioimmunoprecip
itation and anti-insulin by radioimmunoassay. There was a positive tes
t for anti-GAD in 25 (78 %), and for IAA in 23 (72 %), of the 32 predi
abetic ICA-positive subjects. Stratification according to age at the o
nset of diabetes showed differing frequencies of anti-GAD and IAA in t
he prediabetic stage. Thus the positivity rate for anti-GAD for 18 sub
jects older than 10 years at onset of diabetes was 83 %, and for 14 ag
ed 10 or younger at onset was 71 %; conversely, the rate for IAA for 1
8 subjects older than 10 at onset was 56 % and for 14 aged 10 or less
at time of onset was 93 % (p = 0.01). The frequency of anti-GAD was hi
gher in females (88 %) than males (71 %) whereas the frequency of IAA
was higher in males (82 %) than in females (60 %). Since autoantibodie
s to GAD and insulin occur in presymptomatic Type 1 diabetes with diff
erences in frequencies by age and gender, the stimuli to autoimmunity
may operate differently at different ages, and may also be gender-rela
ted.