D. Maugendre et al., Combined analysis of long-term anti-beta-cell humoral reactivity in type 1diabetes with and without thyroid disease, DIABETE MET, 25(1), 1999, pp. 28-33
The prevalence and levels of islet-cel[ antibodies (ICA) decrease in the ye
ars following diabetes onset but may persist, particularly in patients with
concomitant autoimmune disease. The aim of this cross-sectional study was
to investigate the frequencies, associations and levels of the major anti-b
eta-cell antibodies in long-standing diabetic patients (median duration : 1
4 years; range 5-47 years) with and without autoimmune thyroid disease (ATD
) in order to consider the specific anti-pancreatic immunologic features as
sociated with endocrine autoimmunity. Both ICA and glutamic acid decarboxyl
ase (GAD) antibody (GAD-A) frequencies were increased in diabetic patients
with ATD (38 vs 23 %, p = 0.03 and 70 vs 21 %, p < 10(-4) respectively). Al
though IA2-A frequency tended to be higher in diabetic patients with ATD, n
o significant difference was seen (37 vs 26 %, p = 0.14). GAO median level
was significantly higher in the diabetic group with ATD (15 vs 5 units, p <
10(-4)). [AZ-A and ICA median levels were similar in both groups. Regardle
ss of the combined analysis performed (ICA/GAD-A, ICA/IA2-A or GAD-A/IA2-A)
, the prevalence of combined antibody positivity was higher in diabetic pat
ients with than without ATD. In bath diabetic populations, ICA and GA-DA we
re significantly associated (p < 10-4), and their levels were correlated (r
= 0.42, p < 10(-4) and r = 0.584, p < 10(-4) respectively). No significant
correlation was seen between IA2-A levels and either ICA or GAD-A titres.
It is concluded that Type 1 diabetes mellitus with ATD is characterised by
increased persistent humoral islet-related reactivity, particularly directe
d towards GAD.