Islet cell-associated autoantibodies in Ethiopians with diabetes mellitus

J Diabetes Complications. 2016 Aug;30(6):1039-42. doi: 10.1016/j.jdiacomp.2016.05.005. Epub 2016 May 7.

Abstract

Background & aims: Our understanding of the role of autoimmunity in the pathogenesis of diabetes in African populations is limited. This study aims to evaluate the prevalence of 4 different islet cell-associated antibodies in Ethiopian patients with diabetes and non-diabetic controls.

Methods: A total of 187 subjects from a diabetic clinic at an Ethiopian hospital were evaluated in a cross-sectional study. Fifty-five patients had type 1 diabetes mellitus (T1DM), 86 had type 2 diabetes mellitus (T2DM) and 46 were non-diabetic controls. Islet cell-associated antibodies were measured using 4 different assays for antibodies against islet cells (ICA), glutamic acid decarboxylase (GADA), insulin (IAA) and the protein tyrosine phosphatase-like IA-2 (IA-2A).

Results: Comparing the antibody positivity in subjects with T1DM versus T2DM, the results were as follows: 29% versus 3.5% for GADA; 21% versus 2.7% for ICA; 27% versus 16% for IAA. In the control group, the only positive result was for IAA at 2%. IA-2A was absent in all groups. The combi-assay for GADA and IA-2A detected all GADA-positive subjects. T2DM patients who were GADA positive had lower BMI, lower C-peptide levels and all of them were on insulin therapy.

Conclusions: Compared to Caucasians, Ethiopians with T1DM have less prevalence of islet cell-associated antibodies, but the rates are higher than in T2DM. GADA is present in Ethiopians, whereas IA-2A seems to be absent. GADA positivity in T2DM correlates with clinical features of T1DM, indicating the existence in Ethiopia of the subgroup, latent autoimmune diabetes in adults.

Keywords: Africa; Ethiopia; GAD, ICA; Islet cell antibodies; Type 1 diabetes.

MeSH terms

  • Adult
  • Autoantibodies / blood*
  • Case-Control Studies
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 1 / blood*
  • Diabetes Mellitus, Type 1 / immunology
  • Diabetes Mellitus, Type 2 / blood*
  • Diabetes Mellitus, Type 2 / immunology
  • Ethiopia
  • Female
  • Glutamate Decarboxylase / immunology
  • Humans
  • Insulin / immunology
  • Islets of Langerhans / immunology*
  • Male
  • Middle Aged
  • Prevalence

Substances

  • Autoantibodies
  • ICA512 autoantibody
  • Insulin
  • Glutamate Decarboxylase