BSPED2013 Oral Communications Oral Communications 3 (6 abstracts)
1University of Birmingham, Birmingham, UK; 2Birmingham Childrens Hospital, Birmingham, UK; 3Sheffield Childrens Hospital, Sheffield, UK; 4Royal London Hospital, London, UK; 5University of Cambridge, Cambridge, UK; 6University of Bristol, Bristol, UK; 7University of Sheffield, Sheffield, UK.
Objectives: To establish the frequency of islet cell autoimmunity in children with a clinical diagnosis of type 2 diabetes (T2DM) and describe associated clinical and laboratory findings.
Methods: We recruited children with: paediatrician diagnosis of T2DM; BMI above 85th centile for age and sex; children with other confirmed diagnoses such as monogenic and type 1 diabetes (T1DM) were excluded. Clinical data was collected into a national database. Blood was taken for diabetes auto-antibody status to exclude diagnoses of T1DM. Autoantibodies were measured using standardised radio-binding assays; GADA and IA-2A with 35-S labelled antigens and IAA with I-125 labelled insulin in the reference laboratory in Bristol.
Results: Of the 130 recruited to the UK national cohort who have had antibody testing to date, 14 (11%) were positive for either GAD2 or IA2 antibodies (AAb positive). Of these, 8 (6%) were positive for a single antibody, and 6 (5%) were positive for both antibodies. Children were not classified as AAb positive if they were only positive for insulin autoantibodies, as this is likely an indicator of previous insulin treatment. Diabetes autoantibody positivity was significantly associated with a reduced pooled C-peptide (median 530 vs 1270 P=0.016), and previous insulin treatment (86 vs 31% P<0.001). There was a trend towards differences in sex, BMI-SDS and HbA1c between the groups, with more girls being antibody negative, the AAb positive group having a lower BMI-SDS, and higher HbA1c.
Conclusion: Approximately 11% of patients presenting with T2DM are in fact autoantibody positive, suggesting a masked diagnosis of T1DM. This is associated with insulin treatment and a reduced C-peptide. This suggests the need to do autoantibody testing on all children with a diagnosis of diabetes, even if it suspected T2DM, and predicts the need for insulin treatment 2 years after diagnosis in AAb positive patients.