Pancreatic autoantibodies, HLA DR and PTPN22 polymorphisms in first degree relatives of patients with type 1 diabetes and multiethnic background.

ABSTRACT

AIM: To evaluate the prevalence of pancreatic auto-antibodies (PAb) as well as its relationship with HLA DR B1 and PTPN22 polymorphisms in first degree relatives (FDR) of Brazilian patients with Type 1 diabetes (T1D) and multiethnic background. METHODS: FDR of patients with T1D were interviewed and blood was sampled for PAb measurement, HLA DRB1 and PTPN22 genotyping. Genotyping was also performed in index cases. RESULTS: In FDR (n=78), 16.7% presented at least one PAb. These individuals had a higher prevalence of HLA DRB1* 03 than others (p=0.03), without differences in PTPN22 genotyping. While the genetic profile was similar in FDR with PAb and their index cases, those without PAb had a lower frequency of HLA DR B1 * 03 than their correspondent patients (p=0.009). CONCLUSION: In this multiethnic population, a significant proportion of FDR of T1D patients had PAb, which was associated with HLA DR B1 * 03 but not with the PTPN22 polymorphism.