RESUMO
Kawasaki disease (KD) is a pediatric systemic vasculitis of unknown etiology wherein genetic influence is suspected. Gene clusters within the HLA region at chromosome 6p21.3 have been linked to KD and other autoimmune disorders. As collagen is a strong autoantigen inducing chronic inflammation in patients with vasculitis, this study tests a hypothesis that single-nucleotide polymorphism (SNP) of a collagen gene, COL11A2, located in this HLA region may affect susceptibility to Kawasaki disease and its arterial sequels. SNP sites rs2294478 (at promoter) and rs2076311 (at intron 19) were genome-typed on 93 KD patients and 680 healthy subjects. Genotypic and allelic frequencies analyses found A allele at rs2076311 as a risk allele for KD. Clinical association study showed protective potential of C/C genotype at rs2294478 and A/A at rs2076311 for developing coronary artery lesions (CALs) in patients. In addition, C-A haplotype of COL11A2 gene associates with KD development and can serve as a genetic marker to differentiate KD patients lacking CALs from those with such lesions. Our findings suggest the involvement of genetic variations of COL11A2 in Kawasaki disease and CAL formation.
Assuntos
Colágeno Tipo XI/genética , Doença da Artéria Coronariana/genética , Predisposição Genética para Doença , Síndrome de Linfonodos Mucocutâneos/genética , Polimorfismo de Nucleotídeo Único , Doenças Autoimunes/genética , Criança , Cromossomos Humanos Par 6/genética , Colágeno Tipo XI/biossíntese , Doença da Artéria Coronariana/etiologia , Vasos Coronários/patologia , Marcadores Genéticos , Variação Genética , Genótipo , Haplótipos , Humanos , Síndrome de Linfonodos Mucocutâneos/complicações , Síndrome de Linfonodos Mucocutâneos/patologia , Reação em Cadeia da PolimeraseRESUMO
We report a detection method for C-reactive protein (CRP) based on competitive immunoassay using magnetic nanoparticles under magnetic fields. Functional magnetic nanoparticles were prepared and conjugated with anti-CRP for immunoassay. Magnetic nanoparticles labeled with anti-CRP were flowed through a separation channel to form depositions for selective capture of CRP under magnetic fields. Free CRP and a fixed number of CRP-labeled particles were used to compete for a limited number of anti-CRP binding sites on the magnetic nanoparticles. The deposited percentages of CRP-labeled particles at various concentrations of free CRP were determined and used as a reference plot. The determination of CRP in the unknown sample was deduced from the reference plot using the deposited percentages. The running time was less than 10 min. The CRP concentration of serum sample was linearly over the range of 1.2-310 microg/mL for deposited percentages of CRP-labeled particles. The detection limit of this method was 0.12 microg/mL which was approximately 8-fold lower than the typical clinical cutoff concentration (1 microug/mL). This method can provide a fast, simple, and sensitive way for protein detection based on competitive immunoassay using magnetic nanoparticles under magnetic fields.