Diabetes-related antibodies in adult diabetic patients.
Islet autoimmunity is made evident by the appearance of islet-cell antibodies directed against insulin (IAA), glutamic acid decarboxylase (GADA), protein tyrosine phosphatase IA-2 (IA-2Ab) and other autoantigens. IAA and IA-2Ab are predominantly detected in childhood type 1 diabetes mellitus (T1DM), while frequency of GADA is not affected by age. In adult-onset T1DM patients, GADA is the immune marker of higher diagnostic sensitivity. In adult diabetic patients not requiring insulin treatment for at least 6 months after diagnosis, GADA identifies the so-called latent autoimmune diabetes in adults (LADA). In over 80% of cases, LADA patients develop insulin dependency within a few years after the diagnosis and have an increased risk for the development of other organ-specific autoimmune diseases. High GADA titers identify a subgroup of LADA patients with low body mass index (BMI), low C-peptide levels and increased frequency of T1DM-related HLA class II haplotypes. GADA assay should be offered to every diabetic patient, and in cases of positivity screening for other autoimmune diseases should be carried out.
Falorni
Alberto
A
Department of Internal Medicine, University of Perugia, Via E. Dal Pozzo, I-06126 Perugia, Italy. falorni@dimisem.med.unipg.it
Brozzetti
Annalisa
A
D000328:Adult; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology*; D001327:Autoimmune Diseases; D003922:Diabetes Mellitus, Type 1 / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D012307:Risk Factors
D001323:Autoantibodies; C024211:islet cell antibody