Autoimmune disorders such as ATD and CD are relatively common in diabetic children and serological screening studies evaluating the prevalence of CD in patients with T1D have gained momentum in recent years. Rozsai et al (10
) reported EMA positivity of 6.6% in 196 T1D patients. Among these, 1.5% were symptomatic CD cases. The highest association rate (16.4%) was reported by Barera et al (20
). These authors used antigliadin antibody and EMA tests as screening methods (21
). Cherubini et al (22
) reported EMA positivity in 180 cases with T1D and their 116 healthy male siblings as 6.6% and 5.2%, respectively, emphasizing the need for serological screening for CD in siblings of T1D patients.
In our study, the association rate for CD in T1D patients was 7.8%, a rate which conforms to reported data. One of these three patients was completely asymptomatic, one demonstrated extraintestinal symptoms such as short stature and pubertal delay, and the third had uncontrolled diabetes.
Investigations have been focused on the effect of administering a gluten−free diet based on a diagnosis of CD on the metabolic control of diabetes (23
). A diet initiated upon determination of CD in a child with T1D and suffering from malnutrition is expected to lead to weight gain and reduction in the number of hypoglycemic episodes. A decrease in hypoglycemic attacks in pediatric cases with T1D associated with CD after starting a gluten−free diet had been observed by several investigators (21
). However, there are also studies reporting no change in the incidence of hypoglycemia and ketoacidosis by gluten−free diet in children with T1D (24
). We found improvement in the metabolic control in only one CD patients.
The DR3/DQ2 tissue type determined in one of our patients () favors the co−existence of LADC and CD (19
). It has been reported that the CD−related antibodies increase in frequency in the first−degree relatives of T1D patients (25
). Studies have clearly shown that there is a significantly higher incidence of HLA B8, DR3 and DQW2 in CD. The common genetic background may play a role in the immune response mechanism (1
). Recent studies have shown that HLADQ polymorphisms (HLA−DQA1 DQB1) significantly modify the risk of ATD in children with T1D (3
). In our study, 39% T1D patients had DQ8 and 29% had DQ2 genotypes that are known as risk factors in CD.
Characteristics of patients with T1D and CD
Many patients with T1D are euthyroid at the time of diagnosis of ATD. However, overt or subclinical hypothyroidism was reported in 17−58 % of diabetic patients with positive thyroid autoantibodies (26
). In our study, two cases had subclinical hypothyroidism and ten cases were euthyroid.
In conclusion, as also proposed in the literature, we suggest that patients with T1D should be investigated annually for antibodies related to CD and ATD, regardless of presence or absence of symptoms. The number of patients in this study is inadequate to draw a conclusion on the association of HLA genotyping and autoimmune disorders; however, it should be kept in mind that certain HLA groups are prone to autoimmune disorders.