Titre and combination of ICA and autoantibodies to glutamic acid decarboxylase discriminate two clinically distinct types of latent autoimmune diabetes in adults (LADA)

Diabetologia. 2001 Aug;44(8):1005-10. doi: 10.1007/s001250100602.


ABSTRACT AIMS/HYPOTHESIS: This study aimed to define the immunological parameters which could be used to identify patients with the distinct metabolic features of adult latent autoimmune diabetes.

Methods: Sera of 312 patients with short-term diabetes (duration < 5 years) over 35 years of age at diagnosis were screened for ICA, GAD- and IA2-Ab by antibody assays validated in workshops. The antibody status was correlated with age, BMI, residual beta-cell function, measured by fasting C-peptide, onset of diabetes-related complications and markers of the metabolic syndrome (hypertension and hyperlipidaemia).

Results: A total of 51 antibody positive patients were identified. These patients had lower fasting C-peptide and less neuropathy and hypertension compared with matched antibody-negative patients. However, only patients with two or more antibodies had reduced residual beta-cell function compared with antibody-negative or single antibody-positive (ICA or GAD-Ab only) patients. Patients with two or more antibodies were also leaner and had diabetes-related complications or hypertension less frequently than single antibody-positive or antibody negative-patients. IA2 antibody status did not substantially contribute to the diagnosis or differentiation of LADA patients.

Conclusion/interpretation: We concluded that the combination of ICA and GAD antibodies and high titre of GAD antibodies are characteristic of patients with insulin deficiency with the clinical features of Type I (insulin-dependent) diabetes mellitus (LADA-type 1). Single antibody positivity and low titre antibodies are markers for LADA-type 2 associated with the clinical and metabolic phenotype of Type II (non-insulin-dependent) diabetes patients.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Autoantibodies / blood*
  • Autoimmune Diseases / immunology*
  • Body Mass Index
  • C-Peptide / blood
  • Diabetes Mellitus, Type 1 / immunology*
  • Diabetes Mellitus, Type 1 / physiopathology
  • Fasting
  • Glutamate Decarboxylase / immunology*
  • Humans
  • Islets of Langerhans / immunology*
  • Islets of Langerhans / physiopathology
  • Middle Aged


  • Autoantibodies
  • C-Peptide
  • Glutamate Decarboxylase