RESUMEN
A novel human leucocyte antigen-DRB1*16 (HLA-DRB1*16) allele (DRB1*1609) has been identified by sequencing-based typing (SBT) in Chinese Han population. This new allele has identical nucleotide sequence to DRB1*160101 in exon 2, except for a single-nucleotide substitution from A to T at position 127. This change leads to an amino acid change from tyrosine to phenylalanin at residue 47 (Y47F). SBT was performed for cloned DRB1*16-specific polymerase chain reaction fragment. The serological phenotype of DRB1*1609 is equivalent to DR16 antigen.
Asunto(s)
Antígenos HLA-DR/genética , Alelos , Secuencia de Bases , China , Exones , Salud de la Familia , Femenino , Cadenas HLA-DRB1 , Prueba de Histocompatibilidad , Humanos , Masculino , Datos de Secuencia Molecular , Linaje , Fenotipo , Fenilalanina/química , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido Nucleico , Tirosina/químicaRESUMEN
A novel HLA-B*07 allele, B*0740, has been identified by sequence-based typing (SBT) in the Chinese Han population. This new allele is identical to B*0705 and B*0706 for exons 2, 3, and 4, except for a single nucleotide at position 605 of codon 202 in exon 3 (AAG-->ATG) leading to an amino acid change from lysine to methionine. SBT was performed following allele separation using the Haploprep method. The serological equivalence of B*0740 to the B7 antigen did not change.
Asunto(s)
Alelos , Antígenos HLA-B/genética , Secuencia de Aminoácidos , Pueblo Asiatico , Secuencia de Bases , Exones , Variación Genética , Antígeno HLA-B7 , Antígenos HLA-DR/genética , Antígenos HLA-DR/inmunología , Cadenas HLA-DRB1 , Prueba de Histocompatibilidad , Humanos , Datos de Secuencia Molecular , Mutación PuntualRESUMEN
OBJECTIVE: Celiac sprue is associated with specific HLA-DQ genes (mainly DQ2). Because there are epidemiological and histopathological similarities between celiac sprue and microscopic colitis, we hypothesized that these syndrome may share an HLA genetic predisposition and pathogenesis. METHODS: The HLA-DQ genes of 25 patients with celiac sprue, 53 patients with the microscopic colitis syndrome, and 429 normal controls were typed and compared. Serum was analyzed for antigliadin and antiendomysial antibodies. Small intestinal biopsies were analyzed for signs of histopathology. RESULTS: HLA-DQ2 or DQ1,3 (the latter as DQ1,7,DQ1,8, or DQ1,9) were seen more frequently in both patient groups relative to controls. In patients with the microscopic colitis syndrome, serological tests for celiac sprue were weakly positive in 17%; mild inflammation of the small intestine without villous atrophy was present in 43%, and inflammation plus partial or subtotal villous atrophy was present in 27%. CONCLUSIONS: A shared set of predisposing HLA-DQ genes account for the epidemiological overlap of celiac sprue and microscopic colitis. Mild to moderate mononuclear cell inflammation of the small intestine, often accompanied by partial or subtotal villous atrophy, is frequent in patients with the microscopic colitis syndrome. Although further studies will be necessary to determine if this enteropathy is induced by dietary gluten, we speculate that the small intestinal but not colonic histopathology in patients with microscopic colitis is caused by immunological gluten sensitivity.
