Research of anti-GAD and anti-IA2 autoantibodies by ELISA test in a series of Moroccan pediatric patients with diabetes type 1.

INTRODUCTION: Type I diabetes (T1D) is an autoimmune disease with a prediabetic, asymptomatic period characterized by the selective destruction of insulin-producing ß cells. During the pre-clinical phase, various auto-antibodies are generated against several beta cell antigens such as anti glutamate acid decarboxylase (Anti-GAD), anti tyrosine phosphatase (Anti-IA2). Today, the coupled detection of Anti-IA2 with that of Anti-GAD proves its great importance in the diagnosis and prediction of type 1 diabetes. The combined positivity for both antibodies has a specificity and a positive predictive value of 100%. OBJECTIVES: In this work, we evaluate the diagnostic value of anti-GAD and anti-IA2 antibodies in a series based on 78 Moroccan subjects initially under 16, suspected T1D. RESULTS AND DISCUSSION: Our series consists mainly of 74% of newly diagnosed patients for T1D and 26% of confirmed diagnostic patients, of whom 52% are females. The mean age of diagnosis is 7 ± 4 years, the mean of HbA1c at the time of diagnosis is 11.63 ± 2.16%, and the percentage of family history in our series is 69%. The proportion of positive results for anti-IA2 antibodies and anti-GAD antibodies are, respectively, 76.92% and 62.82%, and 52.56% of patients are positive for both auto-antibodies. This study confirms that anti-GAD and anti-IA2 auto-antibodies assays can detect patients early and the autoantibodies can persist several years after diagnosis of type 1 diabetes. CONCLUSION: This study confirmed the diagnosis and classification of T1D (type 1A) in 87.18% of patients, and we reported that the prevalence of anti-GAD and anti-IA2 is higher in girls than in boys.

[Thyroiditis and gluten intolerance: extrapancreatic auto-immune diseases associated with type 1 diabetes]. / Thyroïdite et intolérance au gluten: maladies auto-immmunes extrapancréatiques associées au diabète de type 1.

OBJECTIVES: This study aimed at evaluating the screening of thyroïditis and coeliac disease, in a population of children and adolescents with type 1 diabetes, and at comparing the appearance of antibodies specific for these 2 diseases as a function of age. PATIENTS AND METHODS: The study included 370 children and adolescents, 179 girls and 191 boys, aged 13.8 +/- 4.4 yr and with diabetes for 7.1 +/- 3.8 yr. Auto-immune thyroïditis was screened using antimicrosomal and antithyroglobulin auto-antibodies, at a mean rhythm of 3 tests per patient (1 every 2 yr), associated with dosages of TSH and FT4. Coeliac disease was screened using antigliadin (+/- antiendomysium) auto-antibodies, at a mean rhythm of 2 tests per patient, and was confirmed by duodenojejunal biopsy. Antithyroïd auto-antibodies were correlated with age following the "censured data analysis" type approach. RESULTS: Antithyroïd autoantibodies were found in 42 patients (11.4%), of whom 9 were treated for hypothyroïdism and 1 for Basedow disease, and coeliac disease autoantibodies were found in 9 patients (3.2% of tested patients). The cumulated frequency of antithyroïd auto-antibodies increased regularly with age and was significantly higher in girls, reaching 28% in girls and 12% in boys around 18 yr of age. As a consequence of this evolution, antithyroïd auto-antibodies were frequently found at the time of diagnosis of diabetes when it declared after 10 yr of age, while they often became positive secondarily when diabetes occurred before 10 yr of age. Coeliac disease specific auto-antibodies appeared much earlier and were found at the time of diagnosis of diabetes or at the first screening test. CONCLUSION: Antithyroïd autoantibodies are increasingly frequent with age in children with type 1 diabetes, and become very elevated in girls. The rhythm for screening should be adapted to this evolution of autoantibodies with age, which is very different between thyroïditis and coeliac disease.