Antibodies to Glutamic Acid Decarboxylase in Syrian and Jordanian Type 1 Diabetes Patients and their Siblings

Abstract

Background: Attempts to identify the earliest events in the autoimmune process in type 1 diabetes mellitus suggest that glutamic acid decarboxylase (GAD) is one of the first and most important autoantigens. We conducted this study to determine the prevalence of antibodies to glutamic acid decarboxylase (anti-GAD) in both Syrian and Jordanian children with Type 1 diabetes and their siblings. Patients and Methods: Sera were obtained from 85 Syrian patients with type 1 diabetes (mean age, 13.6±5.9 years), from 45 of their siblings (mean age, 11.3±6.1 years), from 78 randomly selected Syrian control subjects (mean age, 9.9±43 years), and from 95 Jordanian patients with type 1 diabetes (mean age 13.9±65 years), from 78 of their siblings (mean age 12.3±7.1 years), and from 100 randomly selected Jordanian control subjects (mean age, 7.8±4.5 years). Sera were analyzed for anti-GAD using the enzyme linked immunosorbent assay (ELISA) technique. Results: Prevalence of anti-GAD was 34.1% (29/85) in Syrian type 1 diabetes patients, 20% (9/45) in their siblings, 1.3% (1/78) in Syrian control subjects, 49.5% (47/95) in Jordanian type 1 diabetes patients, 23% (18/78) in their siblings, and 2% (2/100) in Jordanian control subjects. Differences between the Syrian and Jordanian type 1 diabetes groups and their siblings and controls were statistically significant. In patients with less than two years of diabetes duration, the frequency was 88.8% (16/18) for both groups. There was no correlation between sex and anti-GAD levels in either Syrian and Jordanian type 1 diabetes patients and their siblings. The positivity of anti-GAD tended to be more frequent at the age range of 5 to 8 years in siblings. Anti-GAD titers >90 ng/mL were found in 58.8% of type 1 diabetes patients and in 38% of siblings who were anti-GAD positive. Conclusion: Syria and Jordan have prevalence rates of anti-GAD among type 1 diabetes patients and their siblings that are among the highest reported in the world. Therefore, anti-GAD may be valuable as an early predictive marker for Type 1 diabetes. Ann Saudi Med 23 (6): 376-380

Pancreatic Autoantibodies in Sudanese Children with Newly Diagnosed Type 1 Diabetes Mellitus

“…This is higher than the previous findings of (46.1%) from Sudan [10], similar to others [21] and lower than those reported from Caucasians (80%) and Japanese (82%) [22]. It is however higher than some regional figures reported among Syrian (34%), Jordanians [23], Saudis [16] and Tunisians [11]. The highest frequency (71%) was found among the 10-15 year -age group though the difference between age groups was not significant.…”