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

Abstract

Background: Immunepositive type one diabetes mellitus is the commonest cause of diabetes in children worldwide. Seronegative cases are said to be more common among black Africans. In a previous study in Sudan 46% of cases were found to have positive GAD antibodies. Objectives of the study: The aim of this study was to find out the prevalence of pancreatic autoantibodies among multiethnic group of newly diagnosed Sudanese children by testing for multiple antibodies and to see how common are seronegative cases as reported in black Africans. Subjects and methods: Eighty newly diagnosed children aged (1-18 years) of multiethnic groups with clinical diagnosis of type 1 diabetes mellitus were tested for 3 islet cell antibodies Glutamic Acid Decarboxylose (GADA), insulin autoantibodies (IAA) and Zinc Transporter (ZNT8A) using ELISA (ZNT8M GADA) and Radioimmunoassay (RIA) for IAA. Demographic and clinical data were obtained from the records-clinical presentations of the….seronegative cases was compared with the seropositive cases. Results: A positive result for one or more antibodies was found in 73 (91.2%) and negative in 7 (8.8%) of the cases-No ethnic variation was demonstrated. There was no difference in the clinical presentation of the two group. IAA was positive in 29 (36.3%), GADA in 62 (77.5%) and ZNT8A in 13 (16.3%). On testing for two antibodies, the best yield was on combining GADA and IAA 61 (76.3%). Conclusion: Unlike the previous study from Sudan most (91.2%) of Sudanese children with Type 1 diabetes have got one or more pancreatic antibodies at onset. However 8.2% are seronegative. Further studies to find the causes in this seronegative group is needed.

Antibodies to Glutamic Acid Decarboxylase-65 is Associated with Total Daily Dose of Insulin Requirement in Children with Type 1 Diabetes

“…(21) In this study, the prevalence of anti-GAD65 autoantibodies was 78.7% in T1D Indonesian children in concordance with the high prevalence of anti-GAD65 in T1D children reported in Western countries, 73.2% in the US and 86% in Europe. (8) Also, these results are in line with a study in Korea that reported that 71% of T1D patients were positive for anti-GAD65 (23) and 77.5% in Sudan (24) but in contrast to previous data that the most idiopathic types are found in Asian and African countries according to low positivity autoimmune markers. (8,14) An anti-GAD65 positivity of 53% has been reported in India (9), 44.3% in Singapore, 34.1% in Syria and 49.5% in Jordan (14).…”

Human Leukocyte Antigen (HLA) and Islet Autoantibodies Are Tools to Characterize Type 1 Diabetes in Arab Countries: Emphasis on Kuwait

“…One example of an IAA is proinsulin, which is the only anti-islet antibody expressed almost exclusively in β -cells [14] and corresponds to the specific targeting of β -cells by the T-cells infiltrating the pancreatic islets. The very high frequency of IAA found in young children upon diabetes onset implied that loss of tolerance to proinsulin was common in those who progress rapidly into the disease [11, 14, 75]. IAAs were also found in a nonobese diabetic mouse model of spontaneous type 1 diabetes [13]; this further supports the role of proinsulin as a primary autoantigen, which is usually the first islet autoantibody to be detected.…”