Background: Children with more than one AID (pediatric polyautoimmunity) may have a stronger genetic component than children with a single AID. PTPN22 C1858T SNP has been associated with multiple different AIDs in adults and children.
Objective and hypotheses: Evaluate the association of PTPN22 C1858T gene polymorphism with pediatric polyautoimmunity.
Method: A cross-sectional study was performed in subjects with an AID of pediatric onset (<18 years) recruited at Pediatric, Endocrinology, Rheumatology and Gastroenterology Clinics at the Health Network of the Pontificia Universidad Católica de Chile School of Medicine. The PTPN22 C1858T gene polymorphism was determined by RT-PCR in subjects with pediatric polyautoimmunity, in subjects with three common AIDs: juvenile idiopathic arthritis (JIA), autoimmune thyroid disease (AITD), type I diabetes (T1D) and in 98 healthy controls.
Results: Genomic DNA from 128 subjects was evaluated for PTPN22 C1858T gene polymorphism revealing common homozygosity (C/C) in 85.2%, heterozygosity (C/T) in 13.3%, and rare homozygosity (T/T) in 1.6%, in equilibrium with Hardy Weinberg Default (P=0.4). 26% of polyautoimmune subjects had the T allele in contrast with 11% of monoautoimmune subjects (P=0.04). No significant difference was found in the age of onset of autoimmunity between mono and polyautoimmune subjects (P=0.44) or between subjects with C/C genotype vs C/T and T/T genotypes (P=0.81).
Conclusion: A higher prevalence of the PTPN22 C1858T polymorphism in pediatric polyautoimmunity, suggesting that this variant may be a risk factor for polyautoimmunity in children with AID.
10 - 12 Sep 2016
European Society for Paediatric Endocrinology